ACOS 5.2.

1-P3
Configuring ACOS Virtual
Chassis Systems
September, 2021
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Table of Contents
Chapter 1: Getting Started 1
Overview 2
VCS Details 2
Virtual Chassis Management Interface (Floating IP Address) 4
VCS Configuration Management 4
VCS Software Version Management 4
VCS Prerequisites 6
Layer 2 Connectivity 6
VCS Image Location 6
vMaster Election 6
Understanding vMaster Election 7
VCS Initial Deployment 7
VRRP-A Active/Standby Device Selection 7
VCS and VRRP-A vMaster Selection 8
vMaster Election During Initial (First-Time) Deployment 8
Initial Virtual Chassis Deployment 9
vMaster Election for Initial Deployment - Same Priority and Boot Time 9
vMaster Election for Initial Deployment - Different Priorities, Same Boot Time 10
vMaster Election Using Dynamic Priority 11
vMaster Election and Heartbeat Messages 12
vMaster Election and Split Chassis 13
Forced vMaster Takeover 14
VCS Configuration Management and Synchronization 15
VCS Configuration Management 16
Automated Configuration Synchronization 17
Manual Configuration Synchronization 19
VCS Software Image Synchronization 19
Customizing the Virtual Chassis 20
Changing the System Time in a Virtual Chassis 21
Configurable VCS Prompts 21
Restoring the Default Prompt Display 22

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Chapter 2: Deploying a Virtual Chassis 23

Initial VCS Deployment 24
Overview 24
Initial vMaster Configuration 25
Initial vBlade Configuration 26
First-Time Deployment Example 27
Topology and Commands 28
vMaster Initial Configuration Example 28
vBlade Initial Configuration Example 32
Forcing vMaster Takeover 34
Procedure 34
Temp-Priority Value 35
Determining a Device’s VCS ID 35
Viewing VCS Information 36
CLI Configuration 37
GUI Configuration 37
VCS CLI-Session Management 37
CLI Message for Commands That Affect Only the Local Device 38
Local Device 38
Message Example 38
Notes 39
Configuring VCS Master Affinity to VRRP-A Active 40
Overview 40
Configuration Example 41
VCS Master Affinity to VRRP-A Active and vMaster Takeover 42
Disabling Syncing of SNMP sysContact OID 42
vMaster Maintenance Mode 43

Chapter 3: Device Management 44

Adding a Device to a Virtual Chassis 44
Overview 44
Procedure 46
Replacing a Device in a Virtual Chassis 47

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Chapter 4: Configuration Synchronization without Reload 48

Usage Summary 48
VRRP-A with VCS Deployment Example 49
Commands on Device 1 49
Commands on Device 2 50

Chapter 5: VCS CLI Commands 52

VCS Operational Commands 53
device-context 53
vcs admin-session-connect 54
vcs disable 55
vcs enable 56
vcs vMaster-maintenance 57
vcs vmaster-take-over 57
VCS Configuration Commands 59
vcs dead-interval 60
vcs debug 60
vcs device 61
vcs failure-retry-count 63
vcs floating-ip 64
vcs floating-ipv6 64
vcs force-wait-interval 65
vcs discovery-mode 65
vcs multicast-ip 67
vcs multicast-ipv6 68
vcs multicast-port 68
vcs reload 68
vcs ssl-enable 69
vcs time-interval 69
vcs unicast-ip 70
vcs unicast-ipv6 70
vcs unicast-port 70
vcs vmaster-maintenance 70
VCS Show Commands 72

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show vcs debug 72

show vcs images 72
show vcs stat 74
show vcs summary 74

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Chapter 1: Getting Started
This section provides an overview of the Virtual Chassis System (VCS).

NOTE: VCS and aVCS, an acronym for ACOS Virtual Chassis System, are
used interchangeably.

The following topics are covered:

Overview 2

VCS Prerequisites 6

vMaster Election 6

VCS Configuration Management and Synchronization 15

VCS Software Image Synchronization 19

Customizing the Virtual Chassis 20

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Overview
The following topics are covered:

VCS Details 2

Virtual Chassis Management Interface (Floating IP Address) 4

VCS Configuration Management 4

VCS Software Version Management 4

VCS Details

ACOS Virtual Chassis System (VCS) enables you to manage a cluster of ACOS devices like a
single, virtual chassis. One ACOS device in the virtual chassis is the virtual master (vMaster).
The other ACOS devices are virtual blades (vBlades) within the virtual chassis, and are man-
aged by the vMaster. As a controller for the vBlades, the vMaster provides centralized storage
of the entire ACOS device configuration. Any configuration changes from the vMaster are
automatically propagated to the vBlades.

VCS, as a management tool, provides high availability functionality on the ACOS device with
the help of VRRP-A across multiple ACOS devices.

Depending on the ACOS series model, with the help of VRRP-A, VCS can support a maximum
7 additional blades. VCS requires that all devices in the same virtual switch have the same
number of CPUs and are the same ACOS device model.

CAUTION: If you use the system-reset command to restore an ACOS

device to its factory default state, the command affects all
ACOS devices in the virtual chassis. The command erases any
saved configuration profiles (including startup-config), as
well as system files such as SSL certificates and keys, aFleX
policies, black/white lists, and system logs. The management
IP address and admin-configured admin and enable pass-
words are also removed. The only workaround is to reload the

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system from a saved configuration or configure the device

once again.

NOTE: Before performing a system- reset , always create a system

backup of the ACOS device to allow you to be able to restore the
ACOS device from the backup when necessary.

VCS elects a single device within the virtual chassis as the vMaster for the chassis. The
vMaster provides a single point of control for all devices in the virtual chassis, as shown in
FIGURE 1-1.

FIGURE 1-1: vMaster - Control Point for all Devices

In addition to individual device management and VCS configurations, the vMaster can also
take care of the following operations on vBlades:

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l Synchronize configurations
l Synchronize certificates
l Synchronize keys
l Synchronize aFleX policies
l Synchronize black/white lists
l Synchronize code versions

Virtual Chassis Management Interface (Floating IP Address)

The virtual chassis has a floating IP address. The virtual chassis’ floating IP address is the
management address for the chassis. To manage a virtual chassis, establish a management
connection (for example, CLI or GUI) to the floating IP address.

When you connect to the virtual chassis’ management IP address, the connection goes to the
vMaster. You can make configuration changes only on the vMaster. The vMaster auto-
matically sends the changes to the vBlades.

If necessary, you can change the context of the management session to a specific vBlade. To
change the management context to the vBlade, use the vcs admin-session-connect com-
mand. The management session will change from the vMaster to the specified vBlade.

NOTE: For more information, see VCS CLI-Session Management.

VCS Configuration Management

When you make a configuration change on the vMaster, the change is sent to the running-
config on each vBlade.

NOTE: For more information, see VCS Configuration Management and

Synchronization.

VCS Software Version Management

The vMaster also ensures that each device in the virtual chassis is running the same software
version.

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NOTE: For more information, see VCS Software Image Synchronization.

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VCS Prerequisites
VCS has the following prerequisite requirements:

l Layer 2 Connectivity
l VCS Image Location

Layer 2 Connectivity

VCS uses IP multicast. All ACOS devices in an VCS virtual chassis must be in the same Layer 2
broadcast domain.

VCS can operate across different geographic regions provided latency is low. VRRP-A session
synchronization will be the gating factor in terms of latency.

NOTE: When using VCS with VRRP-A high availability, the VCS man-
agement address (virtual chassis’ floating IP address) should not
be the same as a VRRP-A floating IP address of the VRID.

VCS Image Location

The VCS-capable image must be installed in the same image area on each device. For
example, install the image in the primary image area of the hard disk or solid state drive
(SSD) on each device.

vMaster Election
This section contains information about vMaster election in a virtual chassis and the factors
that help determine which device becomes the vMaster.

The following topics are covered:

Understanding vMaster Election 7

vMaster Election During Initial (First-Time) Deployment 8

vMaster Election Using Dynamic Priority 11

vMaster Election and Heartbeat Messages 12

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vMaster Election and Split Chassis 13

Forced vMaster Takeover 14

Understanding vMaster Election

The devices in a virtual chassis use a vMaster election process to elect the vMaster for the vir-
tual chassis.

The following topics are covered:

VCS Initial Deployment 7

VRRP-A Active/Standby Device Selection 7

VCS and VRRP-A vMaster Selection 8

To understand when a vMaster will take over as the Active device, it is necessary to under-
stand different configuration scenarios that impact vMaster selection for VCS, for VRRP-A,
and for VCS with VRRP-A:

VCS Initial Deployment

For initial configuration, each ACOS device in the virtual chassis is assigned a VCS device ID
and VCS priority. An ACOS device becomes the vMaster if it has the highest configured VCS
priority among all the other ACOS devices in the virtual chassis. If all ACOS devices in the
VCS configuration have the same VCS priority, then the ACOS device with the lowest device
ID will become the vMaster. In this configuration, each ACOS device will be a stand-alone
device, without any active or standby pairs.

To avoid having to configure each individual ACOS device separately, it is recommended that
you configure only one ACOS device that will serve as the vMaster then have the vMaster
automatically configure the remaining ACOS devices in the virtual chassis.

VRRP-A Active/Standby Device Selection

When VRRP-A is configured, the Active device selection is based on two factors, weight and
priority, before electing an Active device that will have several Standby devices ready to take
over that role. An ACOS device will become an Active or Standby device depending on the
weight or priority of that device. The weight of an ACOS device will always take precedence
over the priority. If we have a higher weight but a lower priority, the ACOS device with the
higher weight will be the Active. If the weight of the devices are equal, the ACOS device with

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the higher priority will become the Active ACOS device. If the weight and the priority of the
devices are equal, the ACOS device will the lowest VRRP-A device ID will be the Active ACOS
device.

As a ACOS device user, configure VRRP-A using VRRP-A failover templates and VRRP-A
tracking options to adjust the weight (using failover templates) or priority (using global track-
ing options) of an ACOS device and elect an Active device.

NOTE: For more information, see Configuring VRRP-A High Availability.

VCS and VRRP-A vMaster Selection

When VCS and VRRP-A are configured to work in conjunction, all ACOS devices will be able
to process traffic as an Active/Standby pair, but these Active/Standby pairs will be con-
figurable using a single ACOS device. The VRRP-A concept of having an Active device and a
Standby device to process traffic will remain the same. However, with VCS, you can con-
figure the Active and Standby devices using a single ACOS device.

In summary, VCS has its own configured priority and dynamic priority for electing the
vMaster not for electing the Active or Standby device. Use the show vcs statistics command
to display the configured and dynamic priority.

VRRP-A has its own weight and priority algorithm to determine which ACOS device is the Act-
ive or the Standby device, however, it does not elect the vMaster. Use the show vrrp-a com-
mand to display the weight and priority for the devices running VRRP-A. For details on how a
failover occurs based on weight or priority using a template, refer to “Event Tracking for
Weight or Priority” in Configuring VRRP-A High Availability. You can force a device to serve
as a vMaster without dynamic election by temporarily assigning it a higher priority.

vMaster Election During Initial (First-Time) Deployment

The following topics are covered:

Initial Virtual Chassis Deployment 9

vMaster Election for Initial Deployment - Same Priority and Boot Time 9

vMaster Election for Initial Deployment - Different Priorities, Same Boot Time 10

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Initial Virtual Chassis Deployment

For initial virtual chassis deployment, the vMaster is elected based on one of the following
parameters:

l Priority – The device with the highest configured VCS priority is elected to be the
vMaster. If you boot one of the devices first and allow it to become the vMaster, the
device remains the vMaster when the other devices join the virtual chassis, even if the
configured priority is higher on another device. This is due to the dynamic priority
value assigned by VCS.

NOTE: For more information, see Initial Virtual Chassis

Deployment.

l Device ID – If all devices have the same configured priority, the device with the lowest
VCS device ID is elected to be the vMaster.

NOTE: For more information, see vMaster Election for Initial Deploy-
ment - Same Priority and Boot Time and vMaster Election
for Initial Deployment - Different Priorities, Same Boot
Time.

vMaster Election for Initial Deployment - Same Priority and Boot Time
FIGURE 1-2illustrates vMaster selection in a virtual chassis where all devices have the same
priority and are booted up at the same time. In this situation, the device with the lowest
device ID (Device 1) is elected as the vMaster.

FIGURE 1-2: vMaster Election in Initial Deployment - Same Priority Value on each Device

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vMaster Election for Initial Deployment - Different Priorities, Same Boot Time
FIGURE 1-3illustrates vMaster selection in a virtual chassis where each device has a different
priority, and all devices are booted up at the same time. In this situation, the device with the
highest priority (Device 4) is elected as the vMaster.

FIGURE 1-3: vMaster Election in Initial Deployment - Different Priority Values Configured

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vMaster Election Using Dynamic Priority

The configurable VCS priority is a static value in each device’s configuration. After a virtual
chassis becomes active, another priority value, the dynamic priority, becomes the most
important parameter when electing the vMaster. The device with the highest dynamic pri-
ority always becomes the vMaster.

The dynamic priority adds stability to the virtual chassis, by consistently using the same
device as vMaster whenever possible. Once a device becomes vMaster, its dynamic priority
ensures that it will remain the vMaster, even if another device has a higher configured pri-
ority. For example, if the vMaster becomes unavailable and a vBlade transitions to vMaster,
the new vMaster remains in control even if the previous vMaster rejoins the virtual chassis.

The following FIGURE 1-4 shows an example of how dynamic priority works. Device 3 was
booted first, and even though other devices have higher priority values, dynamic priority
keeps Device 3 as the vMaster.

FIGURE 1-4: vMaster Election with Dynamic Priority

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Dynamic priority is not configurable. However, you can force a vBlade to become the vMaster.
(See Forced vMaster Takeover.)

vMaster Election and Heartbeat Messages

At regular intervals (the heartbeat time interval), the vMaster sends heartbeat messages to
each of the vBlades, to inform them that the vMaster is still up, as shown in the FIGURE 1-5.

FIGURE 1-5: Heartbeat Messages

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If a vBlade does not receive a heartbeat message within a specified amount of time (heart-
beat dead interval), the vBlade changes its state from vBlade to vMaster-candidate, and
engages in the vMaster election process with the other devices that are still up.

The default heartbeat time is 3 seconds. The default heartbeat dead interval is 10 seconds.
Both parameters are configurable.

vMaster Election and Split Chassis

If one or more vBlades lose contact with the vMaster, the vMaster remains in control for the
vBlades that can still receive the vMaster’s heartbeat messages. However, the other vBlades
use the vMaster election process to elect a new vMaster. This results in two separate virtual
chassis (a “split chassis”), as shown in the FIGURE 1-6.

FIGURE 1-6: vMaster Election - Split Chassis

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After the links among the disconnected devices are restored, the devices again use the
vMaster election process to elect a vMaster. Generally, the vMaster that was in effect before
the virtual chassis divided continues to be the vMaster after the virtual chassis is rejoined,
based on the device’s dynamic priority value (see Initial Virtual Chassis Deployment).

Forced vMaster Takeover

You can force a vBlade to take over as vMaster, without changing the vMaster-election pri-
ority values configured on the devices. For example, you can force a vBlade to take over the
vMaster role, without changing the VCS profiles of any of the devices.

FIGURE 1-7: Forced vMaster Takeover

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NOTE: For a configuration example, see Forcing vMaster Takeover.

VCS Configuration Management and Synchronization

This section describes how configuration changes are handled within the virtual chassis.

The following topics are covered:

VCS Configuration Management 16

Automated Configuration Synchronization 17

Manual Configuration Synchronization 19

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VCS Configuration Management

When you make a configuration change on the vMaster, the change is simultaneously propag-
ated to the running configuration on each vBlade. For example (FIGURE 1-8), if you create a
new SLB server “RS1” on the vMaster, the vMaster sends the server to the running con-
figuration on each of the vBlades.

When the configuration on the vMaster is saved, the vMaster writes the contents of its run-
ning configuration to its startup configuration and performs the same action on each vBlade
in the virtual chassis.

FIGURE 1-8: VCS Configuration Management

Once the virtual chassis is fully operational, all devices in the virtual chassis have exactly the
same set of configuration profiles. This includes the startup configuration and any custom
configuration profiles.

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Automated Configuration Synchronization

VCS automatically synchronizes configuration information within the virtual chassis. Con-
figuration changes are synchronized in real-time as they occur.

All configuration changes are synchronized, even changes to device-specific parameters

such as hostnames and IP addresses. VCS configuration synchronization ensures that each
device in the virtual chassis has a complete set of configuration information for itself and for
each of the other devices. For example, configuration synchronization ensures that each
device has the complete VCS configuration for the virtual chassis (FIGURE 1-9).

FIGURE 1-9: VCS Device-Specific Parameters

In this example, the device-specific portions of the configuration are shown in enlarged text
bold type for each device.

NOTE: For brevity, some commands are omitted from the illustration.
For example, in a working configuration, the vcs enable com-
mand normally would appear in the configuration for each
device, under the vrrp-a commands, and the enable command
would appear among the VCS commands for each device.

Common parameters, such as SLB parameters, are shared by all devices in the virtual chassis
and do not have a device ID (FIGURE 1-10).

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FIGURE 1-10: Common Parameters

Interface parameters are unique to each device and include the VCS device number (FIGURE
1-11).

FIGURE 1-11: Interface Parameters

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This example shows the configuration for each device’s management IP address and an Eth-
ernet interface. VLANs, Virtual Ethernet (VE) interfaces, and trunks also include the VCS
device ID.

Manual Configuration Synchronization

Optionally, you can manually synchronize the VRRP-A configuration to specific devices. For
more information on manual synchronization using VRRP-A, refer to “Manually Synchronizing
the Configuration” in Configuring VRRP-A High Availability.

VCS Software Image Synchronization

In addition to the configuration repository, each device in the virtual chassis also has a soft-
ware image repository. When a new or rebooted device joins the virtual chassis as a vBlade,
the device compares its running software image version with the version running on the
vMaster. If the version on the vMaster is newer, the vBlade downloads the image from the
vMaster, then reboots to place the image into effect.

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When a vBlade upgrades in this way, the new image replaces the older image, in the same
image area. For example, if the vBlade boots the older image from the primary image area on
the hard drive, the upgrade image downloaded from the vMaster replaces the image in the
primary image area.

NOTE: When the web GUI image is upgraded on the vMaster, it gets syn-
chronized to all vBlades.

Customizing the Virtual Chassis

This section contains information for customizing items related to VCS configuration.

The following topics are covered:

Changing the System Time in a Virtual Chassis 21

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Configurable VCS Prompts 21

Restoring the Default Prompt Display 22

Changing the System Time in a Virtual Chassis

If you need to set or change the system time on a vBlade in a virtual chassis, make sure to
make the change on the vMaster, not directly on the vBlade.

This is especially important if you need to set the time ahead on the vBlade. In this case, if
you set the time ahead directly on a vBlade, that device leaves, then rejoins the virtual
chassis, and the change does not take effect.

Configurable VCS Prompts

The CLI prompt can be configured to reflect the VCS chassis device ID and status.

To explicitly enable display of information items in the CLI prompt, use the following com-
mand at the global configuration level of the CLI:
terminal prompt info-item-list

The info-item-list can contain one or more of the following values:

l vcs-status [chassis-device-id] – Enables display of the aVCS status of the device.

The chassis-device-id option enables display of the virtual chassis ID and device ID.
l hostname – Enables display of the ACOS hostname.

l chassis-device-id – Display aVCS device id in the prompt. For example, this can be
7/1, where the number 7 indicates the chassis ID and 1 indicates the device ID within
the aVCS set.

NOTE: The aVCS Chassis ID and the aVCS Device ID are configurable as
part of the prompt if aVCS is running. The prompt that you spe-
cify will be synchronized and reflected on all the other devices in
the aVCS set.

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Restoring the Default Prompt Display

To re-enable display of all the information items, use the no terminal prompt global con-
figuration command.

The following command disables display of the aVCS status and hostname in the CLI prompt:
ACOS2-Active-vMaster[1/1](config)# terminal prompt ha-status
Active(config)#

The following command re-enables display of all the information items:

Active(config)# no terminal prompt
ACOS2-Active-vMaster[1/1](config)#

NOTE: For more information, see “VRRP-A / VCS Status in Command

Prompt” in the Command Line Interface Reference.

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Chapter 2: Deploying a Virtual Chassis
This section describes how to deploy VCS.

The following topics are covered:

Initial VCS Deployment 24

Forcing vMaster Takeover 34

Determining a Device’s VCS ID 35

Viewing VCS Information 36

VCS CLI-Session Management 37

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Initial VCS Deployment

This section describes how to deploy VCS for the first time.

The following topics are covered:

Overview 24

Initial vMaster Configuration 25

Initial vBlade Configuration 26

First-Time Deployment Example 27

CAUTION: Use this procedure only for first-time deployment of VCS. If

you are upgrading ACOS devices on which VCS is already con-
figured, refer to the upgrade instructions included with the
release notes for your release.

Overview

The following TABLE 2-1 summarizes the steps in the procedure for initial VCS deployment.

TABLE 2-1 : Summary of Steps for Initial VCS Deployment

Step Description and Documentation

1 Complete VCS configuration on the device that will be the vMaster.

NOTE: See Initial vMaster Configuration for more inform-

ation.

2 After completing VCS configuration on the vMaster, enable VCS on the vBlades,
and configure VCS-related parameters for the vBlades.

NOTE: See Initial vBlade Configuration for more inform-

ation.

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Step Description and Documentation

3 Reload VCS on the vBlades. At this point, the vMaster synchronizes the con-
figuration to the vBlades.

NOTE: This step is not required when deploying VCS in the

GUI; when VCS is enabled the GUI automatically per-
forms the system reload to synchronize con-
figurations.

4 View the running-config on the vMaster and on the vBlades to verify that both
the vMaster and vBlades configurations are synchronized.

The steps above establishes the first-time base VCS configuration syn-
chronization between vMaster and vBlades. After this, subsequent configuration
changes on the vMaster are automatically synchronized to the vBlades.

5 If you plan to use Layer 3 virtualization, configure it on the vMaster.

Initial vMaster Configuration

To configure the vMaster for the first time:

1. If you have not already done do, configure basic system settings:
l Management interface and default gateway
l Hostname
l Ethernet interfaces
l VLANs
l Routing

2. Configure the following VCS settings related to VRPR-A high availability:

l Chassis ID – Assign each device to the same set (this is the VRRP-A set ID).
l Device ID – Assign a unique device ID to each device (this is the VRRP-A device
ID).
3. Enable VCS.

4. Configure the floating IP address that will be used by the virtual chassis.

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The floating IP address must be in the same subnet as the ACOS device’s management
IP address or one of the device’s data interface IP addresses.

5. Configure VCS device settings:

l vMaster-election interface – Ethernet interface(s) to use for vMaster election. Gen-
erally, these are the interfaces connected to the other devices in the virtual
chassis. The election interfaces for devices in a VCS virtual chassis must be in the
shared partition. Use of an L3V private partition’s interface as a VCS election inter-
face is not supported.

l (Optional) vMaster-election priority – If you want a specific device to serve as the

vMaster for the virtual chassis, set that device’s VCS priority to 255. You can
leave the priority set to its default value on the other devices, which will become
vBlades.

To allow VCS to select the vMaster based on VCS device ID, leave the vMaster-
election priority on all devices unchanged.

NOTE: It is recommended not to disable any of the vMaster election inter-

faces. Doing so can interrupt communication between vMaster
and vBlade, and cause the vBlade to reload.

See vMaster Initial Configuration Example for an example configuration.

Initial vBlade Configuration

This section provides details for initial vBlade configuration. You must perform these steps on
each device that you want to be a vBlade in the virtual chassis.

1. Configure basic system settings:

l Management interface and default gateway
l Hostname
l Ethernet interfaces
l VLANs
l Routing

2. Configure the following VCS settings related to VRPR-A high availability:

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l Chassis ID – Assign each device to the same set (this is the VRRP-A set ID).
l Device ID – Assign a unique device ID to each device (this is the VRRP-A device
ID).
3. Enable VCS.

4. Configure VCS device settings:

l vMaster-election interface – Ethernet interface(s) to use for vMaster election. Gen-
erally, these are the interfaces connected to the other devices in the virtual
chassis. The election interfaces for devices in an VCS virtual chassis must be in
the shared partition. Use of an L3V private partition’s interface as a VCS election
interface is not supported.

l (Optional) vMaster-election priority – If you want a specific device to serve as the

vMaster for the virtual chassis, set that device’s VCS priority to 255. You can
leave the priority set to its default value on the other devices, which will become
vBlades.

To allow VCS to select the vMaster based on VCS device ID, leave the vMaster-
election priority on all devices unchanged.

NOTE: It is recommended not to disable any of the vMaster election inter-

faces. Doing so can interrupt communication between vMaster
and vBlade, and cause the vBlade to reload.

NOTE: See vBlade Initial Configuration Example for an example con-

figuration.

First-Time Deployment Example

The following topics are covered:

Topology and Commands 28

vMaster Initial Configuration Example 28

vBlade Initial Configuration Example 32

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Topology and Commands

The following commands deploy a virtual chassis containing two devices.

FIGURE 2-2: Sample First-Time VCS Deployment Topology

NOTE: For simplicity, configuration of basic system settings is not

shown.

vMaster Initial Configuration Example

This section provides an example of initial configuration for the vMaster.

vMaster Initial Configuration Example Using the CLI

1. Enable VRRP-A and configure the VRRP-A set ID and device ID:
ACOS# configure
ACOS(config)# vrrp-a common
ACOS(config-common)# set-id 1
ACOS(config-common)# device-id 1
ACOS(config-common)# enable
ACOS-Active(config-common)# exit
ACOS-Active(config)#

NOTE: If VRRP-A is not already configured on your system, the

prompt will show “ForcedStandby” until the system is able
to determine that it should be the active device. When this
happens, the prompt will show “Active” as illustrated in this
example.

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2. Enable VCS:
ACOS-Active(config)#vcs enable
ACOS-Active(config:1)#

NOTE: The “:1” at the end of the prompt, indicating that VCS
enabled and you are on local device 1 (the vMaster). The
device ID was set earlier using the device- id command
under VRRP-A common configuration mode.

3. Configure the floating IP address for the virtual chassis:

ACOS(config:1)#vcs floating-ip 192.168.209.23 /24

4. Configure the VCS profile for the device:

ACOS(config:1)#vcs device 1
ACOS(config:1-device:1)# interfaces management
ACOS(config:1-device:1)# priority 125
ACOS(config:1-device:1)# enable
ACOS(config:1-device:1)# exit
ACOS(config:1)# vcs reload

System configuration has been modified. Save? [yes/no]:yes

Building configuration...
Write configuration to primary default startup-config
[OK]
Running configuration is saved
ACOS(config:1)#

vMaster Initial Configuration Example Using the GUI

1. Enable VRRP-A and configure the VRRP-A set ID and device ID.
a. Hover over System in the menu bar, then select VRRP-A. Ensure Global is selected
under the Settings Tab.
b. Under the General Fields section, select Enable for the VRRP-A Enable field and
configure the Device ID and Set ID by entering a device ID and set ID number in the
respective fields.
c. Click OK.

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2. Configure VCS General Settings:

a. Hover over System in the menu bar, then select aVCS and select Enable in the
aVCS Enable field.

b. Configure the management address for the virtual chassis.

Click +Add in the Floating IP Address section to add a Floating IP address row. In
the IP Address Type field, select IPv4 as the address type from the drop-down list,
then enter 192.168.209.23 as the floating IP management address in the IP

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Address field, and enter /24 as the subnet mask in the Netmask field.
c. Click OK.

3. Configure the aVCS device settings:

a. From the System >> aVCS >> Settings, select the Device tab.
b. Click New Device.
c. In the Device field, specify the device ID.
d. In the Priority field, specify the priority.
e. Select Enable in the Enable field.
f. Select Enable in the Management field.
g. Click Submit.

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vBlade Initial Configuration Example

This section provides an initial configuration example for the vBlade. If your configuration
contains multiple vBlades, this procedure should be repeated on each device.

vBlade Initial Configuration Example Using the CLI

ACOS-2# configure
ACOS-2(config)# vrrp-a common
ACOS-2(config-common)# set-id 1
ACOS-2(config-common)# device-id 2
ACOS-2(config-common)# enable
ACOS-2-ForcedStandby(config-common) #exit
ACOS-2-ForcedStandby(config)# vcs enable
ACOS-2-ForcedStandby(config:2)# vcs floating-ip 192.168.209.23 /24
ACOS-2-ForcedStandby(config:2)# vcs device 2

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ACOS-2-ForcedStandby(config:2-device:2)# interfaces management

ACOS-2-ForcedStandby(config:2-device:2)# priority 120
ACOS-2-ForcedStandby(config:2-device:2)# enable
ACOS-2-ForcedStandby(config:2-device:2)# exit
ACOS-2-ForcedStandby(config:2)# vcs reload

System configuration has been modified. Save? [yes/no]:yes

Building configuration...
Write configuration to primary default startup-config
[OK]
Running configuration is saved
ACOS-2(config:2)#

vBlade Initial Configuration Example Using the GUI

1. Enable VRRP-A and configure the VRRP-A set ID and device ID.
a. Hover over System in the menu bar, then select VRRP-A. Ensure Global is selected
under the Settings Tab.
b. Under the General Fields section, select Enable for the VRRP-A Enable field and
configure the Device ID and Set ID by entering a device ID and set ID number in the
respective fields.
c. Click OK.

2. Configure VCS General Settings:

a. Hover over System in the menu bar, then select aVCS and select Enable in the
aVCS Enable field.

b. Configure the management address for the virtual chassis.

Click +Add in the Floating IP Address section to add a Floating IP address row. In
the IP Address Type field, select IPv4 as the address type from the drop-down list,
then enter 192.168.209.23 as the floating IP management address in the IP
Address field, and enter /24 as the subnet mask in the Netmask field.
c. Click OK.

3. Configure the aVCS device settings:

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a. From the System >> aVCS >> Settings, select the Device tab.
b. Click New Device.
c. In the Device field, specify the device ID.
d. In the Priority field, specify the priority.
e. Select Enable in the Enable field.
f. Select Enable in the Management field.
g. Click Submit.

4. Reload the device:

a. From the System >> aVCS >> Device, select the Actions tab.
b. In the Reload Option drop-down list, select Reload and click Apply.

Repeat this procedure for each device.

Forcing vMaster Takeover

This topic describes how to force a vBlade to take over as the vMaster.

The following topics are covered:

Procedure 34

Temp-Priority Value 35

Procedure

If you need to force a vBlade to take over the vMaster role:

1. Either change the management context to the vBlade or log directly onto the vBlade.

To change the management context to the vBlade, use the vcs admin-session-connect
command. For example, to change management context to the vBlade device 2:
vcs admin-session-connect device 2

2. After you have changed the management context to the vBlade, or logged on directly
to the vBlade, use the vcs vmaster-take-over command. For example:

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vcs vmaster-take-over 215

You are required to specify a temp-priority value (215 in this example). Unless you use
this command on more than one vBlade, it does not matter which value within the
range 1-255 you specify. (See Temp-Priority Value).

Temp-Priority Value

This command does not change the configured VCS priority on the vBlade. The command
only temporarily overrides the configured priority.

If you enter this command on only one vBlade, you can specify any value within the valid
range (1-255). The takeover occurs regardless of priority settings on the current vMaster

If you enter the vcs vmaster-take-over command on more than one vBlade, the device on
which you enter the highest temp-priority value becomes the vMaster

If you enter the same temp-priority value on more than one vBlade, the same parameters
used for initial vMaster election are used to select the new vMaster:

l The device with the highest configured VCS priority is selected. (This is the priority con-
figured by the priority command at the configuration level for the VCS device.)
l If there is a tie (more than one of the devices has the same highest configured VCS pri-
ority), then the device with the lowest device ID is selected.

In either case, the new vMaster is selected from among only the vBlades on which you enter
the vcs vmaster-take-over command.

Determining a Device’s VCS ID

When you log onto the virtual chassis or onto an individual device in the chassis, the device’s
VCS ID is not apparent, unless you modified the device’s hostname to indicate the device ID.

To determine a device’s VCS ID, use the show vcs summary command. The device you are
logged onto is indicated with an asterisk in the State column of the Members section.

l If you are logged directly onto a device through its management interface or a data
interface, the asterisk indicates the device.

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l If you are logged onto the floating IP address of the virtual chassis, the asterisk indic-
ates the vMaster.

(This is true unless you changed the device context of the management session. In this
case, you are logged onto the vBlade to which you changed the device context. See Vir-
tual Chassis Management Interface (Floating IP Address).)

The following example indicates that the device you are logged onto is VCS device 1, indic-
ated by the asterisk for device ID 1 in the “Members” section of the output:

ACOS-Active-vMaster[1/1]# show vcs summary

VCS Chassis:
VCS Enabled: Yes
Chassis ID: 1
Multicast IP: 224.0.0.210
Multicast Port: 41217
Version: 4.0.1.b159

Members(* means local device):

ID State Priority IP:Port Location
-------------------------------------------------------------------------------
1 vMaster(*) 0 192.168.216.201:41216 Local
2 vBlade 0 192.168.216.202:41216 Remote
Total: 2

In the GUI, you can view this information in the main header. Look for this section in the
header:

The Device Context field shows that you are currently working on device 1 in the chassis. In
addition, the field on the left indicates that this device (the local device, indicated by the
asterisk) is the vMaster.

Viewing VCS Information

The following topics are covered:

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CLI Configuration 37

GUI Configuration 37

CLI Configuration

Use the show vcs summary command to view global virtual chassis parameters and the cur-
rent role (vMaster or vBlade) of each device in the virtual chassis:

Use the show vcs images command to view the installed VCS-capable ACOS software image:
ACOS# show vcs images
Image Name Type
aximage_4_0_0_500.tar.gz hd_pri
aximage_2_7_0-P2_53.tar.gz hd_sec
-------- ext

GUI Configuration

From the GUI, navigate to System >> aVCS >> Settings. Click on the Statistics tab, then
select aVCS Summary from the drop-down list. The resulting page shows general VCS stat-
istics and available aVCS-capable images on the device.

Also from the GUI, navigate to System >> aVCS >> Settings, then click on the aVCS Deploy-
ment Summary tab to view information about your virtual chassis deployment.

VCS CLI-Session Management

The following topics are covered:

CLI Message for Commands That Affect Only the Local Device 38

Configuring VCS Master Affinity to VRRP-A Active 40

Disabling Syncing of SNMP sysContact OID 42

vMaster Maintenance Mode 43

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CLI Message for Commands That Affect Only the Local Device

This release provides an option that displays a message when you enter a configuration com-
mand that applies to only the local device. When this option is enabled, a message is dis-
played if you enter a configuration command that affects only the local device, and the
command does not explicitly indicate the device.

The following topics are covered:

Local Device 38

Message Example 38

Notes 39

NOTE: This enhancement is enabled by default and can not be disabled.

Local Device
The “local device” is the device your CLI session is on.

l If you log directly onto one of the devices in the virtual chassis, that device is the local
device. For example, if you log on through the management IP address of a vBlade, that
vBlade is the local device.
l If you change the device context to another ACOS device, that device becomes the
local device.
l If you log onto the virtual chassis’ floating IP address, the vMaster is the local device.

Message Example
The following command sets an aging time for learned MAC entries:
ACOS(config)# mac-age-time 444
This operation applied to device 1

This type of configuration change is device-specific. However, the command does not specify
the device ID to which to apply the configuration change. Therefore, the change is applied to
the local device and the output message displays the device ID results. In this example, the
local device is device 1 in the VCS virtual chassis.

The message is not necessary if you explicitly specify the device, and therefore is not dis-
played:
ACOS(config)# device-context 2

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ACOS(config)# mac-age-time 444 device 2

Notes
l For commands that access the configuration level for a specific configuration item, the
message is displayed only for the command that accesses the configuration level. For
example:
ACOS(config)# interface ethernet 2
This operation applied to device 1
ACOS(config-if:ethernet1/2)# ip address 1.1.1.1 /24
ACOS(config-if:ethernet1/2)#

The message is not displayed after the ip address command is entered, because the
message is already displayed after the interface ethernet 2 command is entered.

The same is true for commands at the configuration level for a routing protocol. The
message is displayed only for the command that accesses the configuration level for
the protocol.
l In most cases, the message also is displayed following clear commands for device-spe-
cific items. An exception is clear commands for routing information. The message is
not displayed following these commands.
l The message is not displayed after show commands.

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Configuring VCS Master Affinity to VRRP-A Active

The following topics are covered:

Overview 40

Configuration Example 41

VCS Master Affinity to VRRP-A Active and vMaster Takeover 42

Overview
Master affinity to VRRP-A Active enables the vMaster device in a virtual chassis to failover
when the Active device in a VRRP-A VRID fails over to a Standby device. When the Standby
device becomes Active, it will also act as the vMaster device in the virtual chassis (FIGURE 2-
3).

FIGURE 2-3: VCS Master Affinity to VRRP-A Active

In this topology, device 1 is the Active device in the VRID. When it fails over, device 2 will
become the Active device, as it has the next highest priority. Device 4, which is currently the

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vMaster in the virtual chassis and is configured with VRID affinity, will follow the update in
VRRP-A and switch to device 2 as the vMaster.

This ensures that the device assuming the master configuration also serves as the active data
path. Configuring the VRID affinity causes the vMaster to stay with a selected VRID. This cap-
ability provides deterministic behavior on the location of the VCS master and the unit pro-
cessing traffic for a particular VRRP-A VRID. It also provides better control to effectively
utilize available bandwidth and facilitates troubleshooting efforts.

Configuration Example
To enable a vMaster failover to the Active device, the shared partition is configured to follow
the Active device on a specified VRID (device running VRRP-A). On each device that is part of
the VCS cluster, including the Active device, issue the affinity-vrrp-a-vrid command. See
vcs device for more information.

The following example snippets configure VRID affinity for four devices in a virtual chassis,
based on the example topology in Overview:

NOTE: The affinity-vrrp-a-vrid must be explicitly configured on all

devices for which you want to enable this feature, and the VRID
must also be the same for all devices.

!
...
vcs device 1
priority 225
enable
affinity-vrrp-a-vrid 0
!
vcs device 2
priority 200
enable
affinity-vrrp-a-vrid 0
!
vcs device 3
priority 150
enable
affinity-vrrp-a-vrid 0
vcs device 4
priority 175

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enable
affinity-vrrp-a-vrid 0

!
vcs local-device 1
...

VCS Master Affinity to VRRP-A Active and vMaster Takeover

VRID affinity and forced vMaster takeover (Forced vMaster Takeover) cannot be used
together; you will see the following message if you try to configure vMaster takeover with
VRID affinity configured:
Take over vMastership: VCS: vmaster take over is not allowed in affinity vrid
state

Once VRID affinity is configured, the vMaster will continue to follow the active device in the
VRID using the existing device priorities. To change the priorities, you must issue the vcs
reload command for the new priorities to take effect.

vMaster takeover can be used to assign a new vMaster without regard to existing priorities;
hence it is not allowed in conjunction with VRID affinity.

Disabling Syncing of SNMP sysContact OID

By default, the SNMP sysContact OID value is synchronized among all member ACOS devices
of an VCS virtual chassis. The current release provides an option to disable this syn-
chronization, on an individual device basis.

NOTE: After configuring this option for an ACOS device, if you disable
VCS on that device, the running-config is automatically updated
to continue using the same sysContact value you specified for
the device. You do not need to reconfigure the sysContact on the
device after disabling VCS.

The following example shows an example; to disable syncing of SNMP contact snmp-admin
on VCS device 2:
ACOS(config)# no snmp-server contact snmp-admin on-device 2

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vMaster Maintenance Mode

In maintenance mode, the vMaster can briefly be placed into maintenance without triggering
a failover of the vMaster role to a vBlade. During the maintenance window, the vBlades con-
tinue to operate, without attempting to failover to the vMaster role.

NOTE: For more information, see the vcs vMaster- maintenance com-
mand.

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Chapter 3: Device Management

The following topics are covered:

Adding a Device to a Virtual Chassis 44

Replacing a Device in a Virtual Chassis 47

Adding a Device to a Virtual Chassis

This section describes how to add a configured ACOS device to a running virtual chassis.

CAUTION: By default, when you add a configured ACOS device to a run-

ning virtual chassis, the device-specific configuration is
retained but the common configuration (SLB and so on) is
replaced by the vMaster.

To allow the vMaster to also replace the new device’s device-

specific configuration, use the disable-merge option when
you reload VCS.

NOTE: If a device has already been a member of a virtual chassis, the

device can not be added to a new virtual chassis.

The following topics are covered:

Overview 44

Procedure 46

Overview

The following FIGURE 3-1 shows the process that occurs when you add an ACOS device that
is already configured to a virtual chassis.

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NOTE: The configuration merge behavior described in this section is the

default behavior. If you want the vMaster to also remove the
device-specific configuration information from the new device,
use the disable-merge option when you reload VCS.

FIGURE 3-1: Previously Configured Device Added to Virtual Chassis and Merged with Virtual
Chassis

The following process occurs when you add a previously configured ACOS device to a virtual
chassis:

1. The previously configured ACOS device (labeled “Configured Device” in the figure) is
connected to the virtual chassis network at Layer 2.

An admin then configures VCS settings on the previously configured device and
reloads VCS.

The VCS reload causes the device to send its VCS configuration and its device-specific
configuration to the vMaster.

2. The vMaster applies the VCS configuration and device-specific configuration to its

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virtual chassis configuration.

The vMaster then synchronizes the device’s configuration to the other vBlades as part
of the normal configuration synchronization process.
3. The vMaster sends its running-config to the device.
4. On the device, the vMaster running-config is saved as the device’s startup-config. To
complete its VCS reload, the device loads its new startup-config. The device is now
another vBlade in the virtual chassis.

Procedure

To add an ACOS device that already has a configuration to a VCS chassis:

1. Make sure the virtual chassis is running:

a. Log onto the floating IP address (management address) of the virtual chassis.
b. View the virtual chassis status using the show vcs summary command
2. Connect the configured ACOS device to the Layer 2 network that contains the other vir-
tual chassis members.

3. Configure VCS settings on the new device and reload VCS.

The following commands show how to configure VCS settings on a configured ACOS
device to be added to a virtual chassis, and reload VCS to activate the VCS con-
figuration:
ACOS# configure
ACOS(config)# vrrp-a common
ACOS(config-common)# set-id 1
ACOS(config-common)# device-id 3
ACOS(config-common_# enable
ACOS-Active(config-common)# exit
ACOS-Active(config)# vcs enable
ACOS-Active(config:3)# vcs floating-ip 192.168.100.169 /24
ACOS-Active(config:3)# vcs device 3
ACOS-Active(config:3-device:3)# interface management
ACOS-Active(config:3-device:3)# priority 197
ACOS-Active(config:3-device:3)# enable
ACOS-Active(config:3-device:3)# exit
ACOS-Active(config:3)# vcs reload

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Following the reload of VCS, the ACOS device joins the virtual chassis as a vBlade, and
its configuration information is migrated to the virtual chassis’ vMaster.
4. Verify that the device is now a member of the virtual chassis using the show vcs sum-
mary command.

NOTE: Do not use the disable-merge option when you reload VCS; this
option is used only when replacing an existing virtual chassis
member with a new device.

Replacing a Device in a Virtual Chassis

By default, when you add an ACOS device to a virtual chassis that is already running, the
device’s configuration information is migrated to the vMaster.

However, if you are replacing a member of the virtual chassis by removing the ACOS device
from the network and inserting another ACOS device of the same model, you may want the
vMaster to migrate the removed device’s configuration information to the new device. In this
case, when you reload VCS on the new device, make sure to use the disable-merge option:

The following commands configure VCS settings on a replacement ACOS device to be inser-
ted into a virtual chassis, and reload VCS to activate the VCS configuration:
ACOS# configure
ACOS(config)# vrrp-a common
ACOS(config-common)# set-id 1
ACOS(config-common)# device-id 3
ACOS(config-common)# enable
ACOS-Active(config-common)# exit
ACOS-Active(config)# vcs enable
ACOS-Active(config:3)# vcs floating-ip 192.168.100.169 /24
ACOS-Active(config:3)# vcs device 3
ACOS-Active(config:3-device:#)# interface management
ACOS-Active(config:3-device:3)# priority 197
ACOS-Active(config:3-device:3)# enable
ACOS(Active(config:3-device:3)# exit
ACOS-Active(config:3)# vcs reload disable-merge

Following the reload of VCS, the ACOS device joins the virtual chassis as a vBlade, and
receives its configuration information from the virtual chassis’ vMaster.

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Chapter 4: Configuration Synchronization
without Reload

The following topics are covered:

Usage Summary 48

VRRP-A with VCS Deployment Example 49

Usage Summary
You can use the Virtual Chassis System (VCS) feature to provide automated configuration
synchronization in VRRP-A deployments, even if you do not plan to use any other VCS fea-
tures. Use of VCS for configuration synchronization provides the following benefits:

l VCS configuration synchronization is automatic and occurs in real time. Each con-
figuration change is synchronized to the other ACOS device(s) as soon as the change
occurs.
l Reload is not required.

FIGURE 4-1shows an example VRRP-A deployment that uses VCS for automated con-
figuration synchronization.

FIGURE 4-1: VCS Used for Automated Configuration Synchronization

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VRRP-A with VCS Deployment Example

The following topics are covered:

Commands on Device 1 49

Commands on Device 2 50

NOTE: The following commands deploy the VRRP-A configuration shown

in VCS Used for Automated Configuration Synchronization.

Commands on Device 1

The following commands configure the VRRP-A set ID and device ID, and enable VRRP-A on
device 1:
ACOS-1# configure
ACOS-1(config)# vrrp-a common
ACOS-1(config-common)# set-id 1
ACOS-1(config-common)# device-id 1
ACOS-1(config-common)# enable
ACOS-1-Active(config-common)# exit
ACOS-1-Active(config)#

The following command enables VCS and configures the floating IP address, which is the
management address for the virtual chassis. The floating IP address must be in the same sub-
net as the ACOS device’s management IP address or one of the device’s data interface IP
addresses.
ACOS-1-Active(config)# vcs enable
ACOS-1-Active(config:1)# vcs floating-ip 192.168.209.23 /24

The following commands configure the VCS profile for the device.
ACOS-1-Active(config:1)# vcs device 1
ACOS-1-Active(config:1-device:1)# priority 110
ACOS-1-Active(config:1-device:1)# interface management
ACOS-1-Active(config:1-device:1)# interfaces ethernet 1
ACOS-1-Active(config:1-device:1)# enable
ACOS-1-Active(config:1-device:1)# exit

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The priority command helps identify this ACOS device as the preferred vMaster. Use a
higher priority value on this device than on the second device.

The interfaces commands identify interfaces that can be used by VCS. It is recommended to
specify more than one interface, to help ensure continued communication in case a link goes
down.

The following commands save the changes and activate the VCS configuration.
ACOS-1-Active(config:1)# write memory
ACOS-1-Active(config:1)# vcs reload

Commands on Device 2

The following commands configure the VRRP-A set ID and device ID, and enable VRRP-A on
device 2:
ACOS-2# configure
ACOS-2(config)# vrrp-a common
ACOS-2(config-common)# set-id 1
ACOS-2(config-common)# device-id 2
ACOS-2(config-common)# enable
ACOS-2(config-common)# exit
ACOS-2-Active(config)# vcs enable
ACOS-2-Active(config:2)# vcs floating-ip 192.168.209.23 /24
ACOS-2-Active(config:2)# vcs device 2
ACOS-2-Active(config:2-device:2)# priority 100
ACOS-2-Active(config:2-device:2)# interface management
ACOS-2-Active(config:2-device:2)# interface ethernet 1
ACOS-2-Active(config:2-device:2)# enable
ACOS-2-Active(config:2-device:2)# exit
ACOS-2-Active(config:2)# vcs reload

System configuration has been modified. Save? [yes/no]:yes

Building configuration...
Write configuration to primary default startup-config
[OK]
Running configuration is saved
ACOS-2-Active(config:2)#

NOTE: When you enter the vcs reload command on the second device,
it receives non- device- specific configuration information from

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the first device. This occurs if the first device already has become
the vMaster for the VCS virtual chassis.

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Chapter 5: VCS CLI Commands
This section describes the commands used to configure Virtual Chassis System (VCS).

NOTE: VCS reload is required to place any VCS-related configuration

changes into effect.

The following topics are covered:

VCS Operational Commands 53

VCS Configuration Commands 59

VCS Show Commands 72

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VCS Operational Commands

This section describes the VCS operational commands.

NOTE: These commands are used to operate VCS, but do not change any
VCS configuration settings. To configure VCS, refer to VCS Con-
figuration Commands.

The following topics are covered:

device-context 53

vcs admin-session-connect 54

vcs disable 55

vcs enable 56

vcs vMaster-maintenance 57

vcs vmaster-take-over 57

device-context

Description Change the context of the CLI session from the vMaster to a vBlade, in
order to configure the vBlade.
This command is used to configure device- specific and routing settings
for an ACOS device in a VCS environment. To configure VCS- related
settings for a device in a VCS environment, use the vcs device
command.
This command can also be applied to certain non- routing configuration
commands (for example, LACP).

NOTE: This command replaces the router device-context command

in previous releases.

Syntax device-context DeviceID

Replace DeviceID with the ID of the target device. The target device is
the device you plan to access. The acceptable values for this parameter
will vary depending on your specific hardware platform.

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Default By default, the vMaster for the virtual chassis is the context of the man-
agement session.

Mode Configuration mode

Example The following example changes the configuration context to device 3 in a

virtual chassis, and changes the hostname of that device to “ACOS3:”
ACOS(config)# device-context 3
All the following configuration will go to device 3
ACOS(config)# hostname ACOS3
ACOS3(config)#

vcs admin-session-connect

Description Open an SSH admin session with a device in a VCS virtual chassis.

Syntax vcs admin-session-connect device DeviceID

Replace DeviceID with the ID of the target device. The target device is
the device you plan to access. The acceptable values for this parameter
will vary depending on your specific hardware platform.

Default By default, the CLI session is on the device you logged onto.

Mode Global Config (on vMaster only)

Usage This command does not apply to device- specific configuration com-
mands. To enter device- specific configuration commands on another
device, use the device-context command instead.
Entering this command on the vMaster creates an SSH connection to the
vBlade, without a password prompt. After the connection is established,
you can enter configuration commands to take effect on the vBlade.
While the connection to the vBlade is in effect, configuration commands
cannot be entered directly on the vBlade through any other
management connections.
If an SSH security warning about the RSA fingerprint is displayed:
• If the RSA fingerprint is correct, enter yes.
• If the RSA fingerprint does not match, enter no. Someone may be
attempting to spoof the device in order to gain information about the
system or network access.

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Example The following command changes the CLI session to VCS device 2. In this
example, this is the first time the command has been used to access
device 2.

ACOS-device1(config)# vcs admin-session-connect device 2

spawn ssh -l admin 192.168.100.126
The authenticity of host '192.168.100.126 (192.168.100.126)'
can't be established.
RSA key fingerprint is
ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.100.126' (RSA) to the
list of known hosts.
Last login: Thu Feb 23 03:33:37 2017 from 10.254.101.80

ACOS system is ready now.

[type ? for help]

TIS-Standby-vBlade[1/2]>enable
Password:***
Last login: Thu Jul 22 21:06:46 2010 from 192.168.3.77
ACOS-device2#

At the Password prompt, enter the password for the admin account on
the target device.

Example The following example shows the CLI response if you accidentally try to
switch to the device you are already on:
ACOS-device1(config)# vcs admin-session-connect device 1
Unnecessary to do such operation to manage local device

vcs disable

Description Disable VCS on the device.

Syntax vcs disable

Default N/ A. This is an operational command rather than a configuration com-

mand.

Mode Privileged EXEC (vMaster or vBlade)

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Usage In addition to disabling VCS on the current device, you can also use
device-context to disable VCS on another device. See examples below.

Example The following example disables VCS on the current device:

ACOS-Active-vMaster[1/1]# vcs disable
ACOS-Active-vMaster[1/1]#

Example The following example switches to device 2 from device 1, then disables
VCS on device 2:
ACOS-Active-vMaster[1/1]# configure
ACOS-Active-vMaster[1/1](config:1)# device-context 2
All the following configuration will go to device 2
ACOS-Active-vMaster[1/1](config:2)# vcs disable
ACOS-Active-vMaster[1/1](config:2)#

vcs enable

Description Enable VCS on the device.

Syntax vcs enable

Default N/ A. This is an operational command rather than a configuration com-

mand.

Mode Privileged EXEC (vMaster or vBlade)

Usage After you enter the vcs enable command, you must enter the vcs
reload command to place any VCS configuration changes into effect
and activate the feature.
Before using this command, many of the VCS commands are not
available from the CLI.
The following example shows the commands available prior to running
the vcs enable command:
ACOS(config)# vcs ?
failure-retry-count VCS retry count after fails to join the
chassis
vMaster-maintenance During this period, vMaster can leave
and come back to
be vMaster again
enable enable VCS
disable disable VCS
ACOS(config)# vcs

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In addition to enabling VCS on the current device, you can also use
device-context to enable VCS on another device. See examples below.

Example The following example enables VCS on the current device:

ACOS-Active-vMaster[1/1]# vcs enable
ACOS-Active-vMaster[1/1]#

Example The following example switches to device 2 from device 1, then enables
VCS on device 2:
ACOS-Active-vMaster[1/1]# configure
ACOS-Active-vMaster[1/1](config:1)# device-context 2
All the following configuration will go to device 2
ACOS-Active-vMaster[1/1](config:2)# vcs enable
ACOS-Active-vMaster[1/1](config:2)#

vcs vMaster-maintenance

Description Change the length of the vMaster maintenance window.

Syntax [no] vcs vMaster-maintenance seconds

Replace seconds with the length of the maintenance window. You can
specify 0- 3600 seconds.

Default The default is 60 seconds.

Mode Privileged EXEC (on vBlade); Privileged EXEC and Global Config (on
vMaster)

Usage VCS option that allows the vMaster to briefly be placed into maintenance,
without triggering failover of the vMaster role to a vBlade. During the
maintenance window, the vBlades continue to operate, without attempt-
ing to failover to the vMaster role.

vcs vmaster-take-over

Description Force vMaster re- election, by temporarily changing a device’s VCS pri-
ority. This command is useful for changing a vBlade to vMaster without
changing the VCS configuration profile for either device.

Syntax [no] vcs vmaster-take-over temp-priority

Replace temp-priority with the priority value, 1- 255.

Default N/ A

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Mode Privileged EXEC (on vBlade); Privileged EXEC and Global Config (on
vMaster)

Usage This command does not change the configured VCS priority on the
device. The command only temporarily overrides the configured priority.
If you enter this command on only one vBlade, you can specify any value
within the valid range (1- 255). The takeover occurs regardless of priority
settings on the current vMaster.
If you enter the vcs vmaster-take-over command on more than one
device, the device on which you enter the highest temp- priority value
becomes the vMaster.
If you enter the same temp- priority value on more than one device, the
same parameters used for initial vMaster election are used to select the
new vMaster:
• The device with the highest configured VCS priority is selected. (This
is the priority configured by the priority command at the con-
figuration level for the VCS device.)
• If there is a tie (more than one of the devices has the same highest
configured VCS priority), then the device with the lowest device ID is
selected.
In either case, the new vMaster is selected from among only the devices
on which you enter the vcs vmaster-take-over command.

Example The following commands change the management context to a vBlade,

then force the device to become the vMaster:
ACOS-1# vcs admin-session-connect device 2
spawn ssh -l admin 192.168.100.126
The authenticity of host '192.168.100.126 (192.168.100.126)'
can't be established.
RSA key fingerprint is
ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.100.126' (RSA) to the
list of known hosts.
Password:
Last login: Wed Aug 11 20:27:24 2010 from 192.168.3.74

[type ? for help]

ACOS>enable
Password:********
ACOS-2#vcs vmaster-take-over 255

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VCS Configuration Commands

This section describes the VCS configuration commands.

These commands are used to configure specific VCS settings, and are available after entering
the device-context global configuration command.

The following topics are covered:

vcs dead-interval 60

vcs debug 60

vcs device 61

vcs failure-retry-count 63

vcs floating-ip 64

vcs floating-ipv6 64

vcs force-wait-interval 65

vcs discovery-mode 65

vcs multicast-ip 67

vcs multicast-ipv6 68

vcs multicast-port 68

vcs reload 68

vcs ssl-enable 69

vcs time-interval 69

vcs unicast-ip 70

vcs unicast-ipv6 70

vcs unicast-port 70

vcs vmaster-maintenance 70

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vcs dead-interval

Description Configure the number of seconds vBlade devices wait for a keepalive
message from the vMaster, before assuming the vMaster is unavailable
and triggering vMaster re- election.

Syntax [no] vcs dead-interval seconds

Replace seconds with the maximum number of seconds to wait for a

keepalive message from the vMaster before triggering vMaster re-
election. You can specify 5- 60 seconds.

Default 10

Mode Global Config (vMaster only)

Example The following example sets the interval to 20 seconds:

ACOS-Active-vMaster[1/1](config:1)# vcs dead-interval 20

vcs debug

Description Enable VCS debugging.

Syntax [no] vcs debug {daemon | election | info | vblade | vmaster}

Parameter Description

daemon Enables debugging for the VCS process.

election Enables debugging for vMaster election.

info Enables display of informational messages in the

debugging output.

vblade Enables debugging for vBlade-related operations.

vmaster Enables debugging for vMaster-related operations.

Default Disabled

Mode Privileged EXEC (on vBlade); Privileged EXEC and Global Config (on
vMaster)

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Example The following commands enable debugging for VCS vMaster operations,
and display the output:
ACOS-Active-vMaster[1/1](config:1)# vcs debug vmaster
ACOS-Active-vMaster[1/1](config:1)# show vcs debug
Debugging switches: vmaster,
Debugging Buffer Size: 8 MB
2010/08/02 10:46:02, [vMaster], vBlade 0, msg loop, received
msg 21
2010/08/02 10:46:02, [vMaster], vBlade 0, msg loop, sent msg
20
...

vcs device

Description Add a device to an existing VCS chassis, and configure VCS- related set-
tings for the specified device.
To configure device- specific or routing settings for an ACOS device in an
VCS environment, use the device-context command.

Syntax [no] vcs device device-id

Replace device-id with the device ID. The acceptable values for this
parameter will vary depending on your specific hardware platform.
This command changes the CLI to the configuration level for the
specified VCS device, where the following VCS-related commands
are available.

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Command Description

[no] affinity- Configures a vMaster failover to the Active

vrrp-a-vrid device on a specified VRID (device running
vrid-group VRRP-A). Use this command on each device
that is part of the VCS cluster, including the
Active device.

NOTE: For more inform-

ation about this fea-
ture, see
Configuring VCS
Master Affinity to
VRRP-A Active.

[no] enable Enables VCS on the device.

VCS is disabled by default.

[no] inter- Device interfaces used for VCS vMaster elec-

faces tion traffic. You can specify up to 6 election
{ethernet port- interfaces.
num |
For vMaster election to work, the other devices
management |
in the virtual chassis must be able to reach the
trunk trunk-
device on the specified interface(s).
num |
ve ve-num}

[no] priority Priority of this device for vMaster election,

num 1-255. Higher priority values are preferred over
lower ones.

The default priority is 0 (not set).

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Command Description

[no] unicast- Protocol port used to create TCP connection

port between the vMaster and vBlade. This con-
portnum nection is used for configuration syn-
chronization.

The default unicast port is 41216.

Default No VCS devices are configured by default. When you add a VCS device,
its parameters have the default values described in the table above.

Mode Global Config (vMaster only)

Usage The election interfaces for devices in an VCS virtual chassis must be in
the shared partition. Use of an L3V private partition’s interface as a VCS
election interface is not supported.

Example The following commands add device 3 to an existing VCS chassis. The
management interface will be used for VCS election traffic and its priority
is 3.
ACOS-Active-vMaster[1/1](config:1)# vcs device 3
ACOS-Active-vMaster[1/1](config:1-device:3)# interfaces man-
agement
ACOS-Active-vMaster[1/1](config:1-device:3)# priority 3
ACOS-Active-vMaster[1/1](config:1-device:3)# enable

vcs failure-retry-count

Description Configure the maximum number of retries for a VCS device to join a vir-
tual chassis.

Syntax [no] vcs failure-retry-count {retries | forever}

Parameter Description

retries Maximum number of retries for a VCS device to join a virtual

chassis. You can specify 0- 255.

forever Specify an unlimited amount of retries for a VCS

device to join a virtual chassis.

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Default 2

Mode Global Config (vMaster or vBlade)

Usage If the device is unable to join the virtual chassis after all allowed retries are
used, VCS stops on the device. In this case, you use the vcs reload com-
mand to restart VCS on the device.

Example The following example configures an ACOS device to try 3 times to join a
virtual chassis:
ACOS-Active-vMaster[1/1](config:1)# vcs failure-retry-count
3

vcs floating-ip

Description Configure the management IP address for the VCS virtual chassis.

Syntax [no] vcs floating-ip ipaddr {subnet-mask | /mask-length}

Specifies the IP address and subnet mask.

Default Not set

Mode Global Config (vMaster or vBlade)

Example The following command sets the management address for the VCS vir-
tual chassis to 192.168.1.69/24:
ACOS-Active-vMaster[1/1](config:1)# vcs floating-ip
192.168.1.69 /24

vcs floating-ipv6

Description Configure an IPv6 management IP address for the VCS virtual chassis.

Syntax [no] vcs floating-ipv6 ipv6-addr/mask-length

Specifies the IP address and subnet mask.

Default Not set

Mode Global Config (vMaster or vBlade)

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Example The following command sets the management address for the VCS vir-
tual chassis to the IPv6 address fc00:0:3::23:a/24:
ACOS-Active-vMaster[1/1](config:1)# vcs floating-ipv6
fc00:0:3::23:a/24

vcs force-wait-interval

Description Delay the start of VCS following a reload/ reboot.

Syntax [no] vcs force-wait-interval seconds

Replace seconds with the number of seconds (5- 240) to wait following a
a reload or reboot to start VCS.

Default 5

Mode Global Config (vMaster or vBlade)

Usage This command can be useful if you use staggered upgrade.

Example The following example configures the device to wait 10 seconds before
starting the reload or reboot:
ACOS-Active-vMaster[1/1](config:1)# vcs force-wait-interval
10

vcs discovery-mode

Description Supports L3 communication in Scaleout.

Syntax [no] vcs discovery-mode ?

Replace ? with unicast, Mcast, or Mixed.

Parameter Description

Unicast Enables VCS Unicast election mode.

Mcast Enables VCS Multicast election mode.

Mixed Enables both VCS Multicast/Unicast election mode.

Default Mcast

Mode Global Config (vMaster or vBlade)

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Usage This command is useful for establishing connectivity between L3 to L2

CGNAT nodes.

NOTE: If users only run “vcs discovery- mode Unicast”, then it removes
vcs interface commands. It the “vcs discovery- mode mcast/ vcs
discovery- mode mixed”, then it reserves vcs interface com-
mands.

Example The following example configures vcs to send its heartbeat to multicast
election address for per 3 seconds, after support unicast election, AX
sends a heartbeat to UDP unicast address. VCS also can be running if ax
is in a different subnet and there are routers in between them.
Ipv4 :
vrrp-a common
device-id 2
set-id 7
!
device-context 1
vcs enable
!
device-context 2
vcs enable
!

vcs device 2
enable

vcs device 1
enable
vcs unicast-election
port 12000
members
ip-address 2.2.2.115
ip-address 2.2.2.116

vcs discovery-mode Unicast

interface ethernet 1/2

enable
ip address 2.2.2.115 255.255.255.0

interface ethernet 2/2

enable

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ip address 2.2.2.116 255.255.255.0

Ipv6:

vrrp-a common
device-id 1
set-id 7
!
device-context 1
vcs enable
!
device-context 2
vcs enable
!
vcs unicast-election
port 12005
members
ipv6-address 3000::115 use-mgmt-port
ipv6-address 3000::116 use-mgmt-port
!

vcs discovery-mode Unicast

multi-config enable
!
device-context 1
interface management
ip address 192.168.105.116 255.255.255.0
ip default-gateway 192.168.105.1
ipv6 address 3000::116/64
!
device-context 2
interface management
ip address 192.168.105.115 255.255.255.0
ip default-gateway 192.168.105.1
ipv6 address 3000::115/64
-Active-vMaster[1/1](config:1)# vcs force-wait-interval 10

vcs multicast-ip

Description Configure the multicast IPv4 address used for VCS vMaster election.

Syntax [no] vcs multicast-ip ipv4-addr

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Replace ipv4-addr with the multicast address.

Default 224.0.0.210

Mode Global Config (vMaster or vBlade)

Usage To configure the protocol port, see vcs multicast-port.

vcs multicast-ipv6

Description Configure the multicast IPv6 address used for VCS vMaster election.

Syntax [no] vcs multicast-ip ipv6-addr

Replace ipv6-addr with the multicast address.

Mode Global Config (vMaster or vBlade)

Usage To configure the protocol port, see vcs multicast-port.

vcs multicast-port

Description Configure the protocol port used for VCS vMaster election.

Syntax [no] vcs multicast-port portnum

Replace portnum with the protocol port number, 1- 65535.

Default 41217

Mode Global Config (vMaster or vBlade)

Usage To configure the multicast address, see vcs multicast-ip.

vcs reload

Description Reload the VCS process.

Syntax vcs reload [disable-merge]

The disable-merge option prevents configuration information from

being migrated from the vBlades to the vMaster following the reload. This
option is useful when you are replacing a virtual chassis vBlade by
removing an ACOS device and replacing it with another ACOS device of

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the same model. In this case, the option allows the replacement device to
be configured by the vMaster.
After the initial configuration migration, configuration synchronization
operates normally.
Without this option, when you add an ACOS device to a virtual chassis
that is already running, the device’s configuration information is migrated
to the vMaster

Default N/ A

Mode Global Config (vMaster only)

Usage VCS reload is required to place any VCS- related configuration changes
into effect.

vcs ssl-enable

Description Enable or disable SSL for configuration synchronization traffic between

VCS devices.

Syntax [no] vcs ssl-enable

Default Disabled

Mode Global Config (vMaster only)

vcs time-interval

Description Number of seconds between keepalive messages from the vMaster to

vBlades.

Syntax [no] vcs time-interval seconds

Replace seconds with the number of seconds between transmission of

keepalive messages from the vMaster to vBlades. You can specify 1- 60
seconds.

Default 3

Mode Global Config (vMaster or vBlade)

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vcs unicast-ip

Description Configure the multicast IPv6 address used for VCS unicast - election.

Syntax [no] vcs unicast-ip ipv6-addr

Replace ipv6-addr with the unicast address.

Mode Global Config (vMaster or vBlade)

Usage To configure the protocol port, see VCS unicast -port.

vcs unicast-ipv6

Description Configure the unicast IPv6 address used for VCS unicast election.

Syntax [no] vcs unicast-ip ipv6-addr

Replace ipv6-addr with the unicast address.

Mode Global Config (vMaster or vBlade)

Usage To configure the protocol port.

vcs unicast-port

Description Configure the protocol port used for VCS unicast election.

Syntax [no] vcs unicast-port portnum

Replace portnum with the protocol port number, 1- 65535.

Default 41217

Mode Global Config (vMaster or vBlade)

vcs vmaster-maintenance

Description Briefly place the vMaster into maintenance mode without triggering a fail-
over to a vBlade.

Syntax vcs vmaster-maintenance period

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Replace period with the amount of time (0- 3600 seconds) that the
vMaster is placed into maintenance mode without triggering a failover.

Default 60 seconds

Mode Global Config (vMaster or vBlade)

Usage The vMaster can be placed into maintenance mode without triggering a
failover to a vBlade. During this maintenance window, the vBlades con-
tinue to operate without attempting to take over the vMaster role. At the
end of the configurable maintenance period, the vMaster returns to the
vMaster role.

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VCS Show Commands

This section describes the VCS-specific show commands.

NOTE: This section only contains VCS-related show commands begin-

ning with “show vcs.” Many other show commands can be used in
a VCS context by specifying the specific ID of a device in the vir-
tual chassis.

NOTE: For more information, see the “Show Commands” section in the
Command Line Interface Reference , or type “ ? ” at the CLI
prompt.

The following topics are covered:

show vcs debug 72

show vcs images 72

show vcs stat 74

show vcs summary 74

show vcs debug

Description Display VCS debug messages.

Syntax show vcs debug [old_first]

Use the old_first option to list messages beginning with the most
recent. Without this option, the list begins with the oldest message in the
buffer.

Mode All

show vcs images

Description Display the VCS- capable software images stored on the ACOS device.

NOTE: Only images that support VCS are listed. To list all images, use the
show bootimage command instead.

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Syntax show vcs images

Mode All

Example The following command shows the VCS- capable software images stored
on the device:
ACOS# show vcs images
Image Name Type
aximage_4_0_1_159.tar.gz hd_pri
aximage_4_0_0_536.tar.gz hd_sec
-------- cf_pri
-------- cf_sec
-------- ext

The following table describes the fields in the command output.

Field Description

Image Name of the software image.

Name

Type Location of the image:

l hd_pri – Primary image area of the hard drive or

Solid State Drive (SSD)
l hd_sec – Secondary image area of the hard drive
or SSD
l cf_pri – Primary image area of the compact flash
drive
l cf_sec – Secondary image area of the compact
flash drive
l ext – Extended image, used for staged upgrades
during which multiple ACOS software versions
run in the virtual chassis.

NOTE: If dashes (- - - - - - - - ) are

displayed instead of an
image name, the image
does not support VCS.

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show vcs stat

Description Display VCS statistics information.

Syntax show vcs stat

Mode All

Example The following command shows statistics of the VCS information:

ACOS# show vcs stat

Chassis-ID: 8
time-interval: 3
failure-retry-count: 2
force-wait-interval: 5
SSL-enabled: No
Multicast-IP: 224.0.0.210
Multicast-Port: 41217
Unicast-elect-Port: 12000
Unicast-election-members: 2
Current discover mode : unicast
Member-IP: 192.168.105.127
Member-IP: 192.168.105.121
Dev-ID: 1
Dev-Prio: 0
Unicast-Port: 41216
Interfaces: management
Enabled: Yes
Local-Dev-ID: 1

show vcs summary

Description Display VCS virtual chassis information.

Syntax show vcs summary

Mode All

Example The following commands show summary of the VCS information:

ACOS# show vcs summary

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VCS Chassis:
VCS Enabled: Yes
Chassis ID: 8
Unicast Election port: 12000
Multicast IP: 224.0.0.210
Multicast Port: 41217
Current discover mode: unicast
Version: 4.1.4-GR1-P1.b19

Members(* means local device):

ID State Priority IP:Port Location
------------------------------------------------------------
-------------------
1 vBlade 0 192.168.105.121:41216 Remote
2 vMaster(*) 0 192.168.105.127:41216 Local
Total: 2

ACOS# show vcs summary

VCS Chassis:
VCS Enabled: Yes
Chassis ID: 8
Unicast Election port: 12000
Multicast IP: 224.0.0.210
Multicast Port: 41217
Current discover mode: unicast
Version: 4.1.4-GR1-P1.b19

Members(* means local device):

ID State Priority IP:Port Location

________________________________________
1 vBlade(*) 0 3000:::116 41216 Local
2 vMaster 0 3000::115:41216 Remote

The following table describes the fields in the command output.

Field Description

VCS Chassis Fields

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Field Description

VCS Enabled State of the VCS feature, Enabled or Disabled.

Chassis ID ID of the virtual chassis.

Unicast
Election
Port

Multicast Multicast IP address used for VCS vMaster election.

IP

Multicast Protocol port used for vMaster election.

Port

Current dis- Specify Discover-mode as Unicast, Mcast or Mixed

cover Mode election mode. To run unicast mode user must spe-
cify Discover-mode is Unicast (vcs discovery-mode
Unicast ) and provide Unicast neighbor con-
figurations.

Version Software version and build running on the ACOS

device.

Members Fields

ID VCS ID of the member device.

State Current role of the device, vMaster or vBlade.

NOTE: If you enter this com-

mand in a session
that is logged onto
the VCS floating IP
address, the “local
device” is always the
vMaster, unless you
change the context
ID of the man-
agement session.

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Field Description

Priority vMaster election priority of the device.

NOTE: This is the admin-

configured priority
value, not the
dynamic priority
assigned by VCS.

IP:Port IP address and protocol port used for configuration

synchronization with the member device.

Location Indicates whether this is the device context on

which you entered the show vcs summary com-
mand:

l Local – This is the device context on which

you entered the command.
l Remote – This is not the device context on
which you entered the command.

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