Routing
Index
● Introduction
● Addressing and subnetting
● Routing
● ARP protocol
● IP header
● ICMP protocol
● DHCP protocol
● NAT mechanism
● RIP dynamic routing
● Security notions
Lucas Bazilio - Udemy
IP Routing
➢ Manner in which datagrams “walk” over the network
Lucas Bazilio - Udemy
IP Routing
➢ Manner in which datagrams “walk” over the network
➢ How does PC1 know that PC2, PC3, … exist?
➢ How can it transmit datagrams to them?
Lucas Bazilio - Udemy
Lucas Bazilio - Udemy
IP Routing
➢ Manner in which datagrams “walk” over the network
→ Routing Table
- Database that each router and host has
- Contains the information necessary to reach all destinations
IP Routing
Acquisition Destination Mask Gateway Interface
Indicates which are the Indicates if to reach Indicates through
Indicates how which interface it is
an entry in the destinations reachable by a destination it is
this device in terms of @IP necessary to go necessary to
table has been transmit to reach
acquired and mask. Destinations can through a router or
be @IP, network addresses, if the destination is the destination
or all destinations in the same
network
Lucas Bazilio - Udemy
IP Routing
Acquisition Destination Mask Gateway Interface
Each entry in this table forms what is called a route to a destination
● A route between source and destination is determined as the sum
of next steps (or hops)
● That is, each element of this network determines only a part of the
entire route.
Lucas Bazilio - Udemy
IP Routing
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
When configuring the @IP of e0 of PC1, this entry is created
Lucas Bazilio - Udemy
IP Routing
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
When configuring the @IP of e0 of PC1, this entry is created
It says how to transmit to the destinations of 10.0.0.0/24
Lucas Bazilio - Udemy
Lucas Bazilio - Udemy
IP Routing
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
When configuring the @IP of e0 of PC1, this entry is created
It says how to transmit to the destinations of 10.0.0.0/24
C: direct connection (PC1 is connected to network 10.0.0.0/24 and can reach all destinations on this network)
Lucas Bazilio - Udemy
IP Routing
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
When configuring the @IP of e0 of PC1, this entry is created
It says how to transmit to the destinations of 10.0.0.0/24
C: direct connection (PC1 is connected to network 10.0.0.0/24 and can reach all destinations on this network)
Gateway 0.0.0.0: indicates that it is not necessary to go through a router, the destinations are local
Lucas Bazilio - Udemy
IP Routing
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
When configuring the @IP of e0 of PC1, this entry is created
It says how to transmit to the destinations of 10.0.0.0/24
C: direct connection (PC1 is connected to network 10.0.0.0/24 and can reach all destinations on this network)
Gateway 0.0.0.0: indicates that it is not necessary to go through a router, the destinations are local
e0: indicates that the interface called e0 must be used to transmit
Lucas Bazilio - Udemy
IP Routing
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
The next step in this case is to send the datagram to the destination that is on the same
network as the source.
Lucas Bazilio - Udemy
IP Routing
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
S 10.0.1.10 255.255.255.255 10.0.0.1 e0
They are all 1s since all We have to go through
The @IP of a host the bits in the router 10.0.0.1 to
Static input Destination column reach the destination
(manually identify the
configured) destination.
Lucas Bazilio - Udemy
IP Routing
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
S 10.0.1.10 255.255.255.255 10.0.0.1 e0
The next step is to pass the datagram to router 10.0.0.1 by transmitting out interface e0
to reach host 10.0.1.10
Lucas Bazilio - Udemy
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
S 10.0.1.10 255.255.255.255 10.0.0.1 e0
S 10.0.2.0 255.255.255.0 10.0.0.1 e0
We have to go through router 10.0.0.1
All destinations of thisIs the mask of the to reach the destination
Static input network destination network
(manually configured)
Lucas Bazilio - Udemy
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
S 10.0.1.10 255.255.255.255 10.0.0.1 e0
S 10.0.2.0 255.255.255.0 10.0.0.1 e0
We have to go through router 10.0.0.1
All destinations of thisIs the mask of the to reach the destination
Static input network destination network
(manually configured)
The next step is to pass the datagram to the router 10.0.0.1 transmitting through the
interface e0 to be able to reach any @IP of the network 10.0.2.0/24
Lucas Bazilio - Udemy
PC1 routing table
Acquisition Destination Mask Gateway Interface
C 10.0.0.0 255.255.255.0 0.0.0.0 e0
S 10.0.1.10 255.255.255.255 10.0.0.1 e0
S 10.0.2.0 255.255.255.0 10.0.0.1 e0
10.0.0.1 e0
S 0.0.0.0 0.0.0.0
Any destination Any mask We have to go through router 10.0.0.1
Static input to reach the destination
(manually configured)
Lucas Bazilio - Udemy
PC1 routing table
Acquisition Destination Mask Gateway Interface
R1 routing table
Acquisition Destination Mask Gateway Interface
Lucas Bazilio - Udemy
PC1 routing table
Acquisition Destination Mask Gateway Interface
R1 routing table
Acquisition Destination Mask Gateway Interface
