listnd is a command line tool for discovery of devices on a network and listing them. The discovery process is passive in the sense that listnd does not send any packets to discover devices on the network. Instead, it only captures packets on a network interface and analyses them.
listnd requires libpcap to capture packets from network interfaces. So, make sure you have libpcap installed. For example on a debian-based distribution:
$ sudo apt install libpcap-devAfter installing dependencies you can download, build and install listnd with
its other dependencies to your GOPATH or GOBIN (usually ~/go/bin/) with the
go tool:
$ go install github.com/hwipl/listnd/cmd/listndYou can run listnd with
$ listndMake sure your user has the permission to capture traffic on the network interface.
You can specify the network interface with the option -i. For example, you
can specify the interface eth3 with:
$ listnd -i eth3Command line options of the listnd command:
-debug
set debugging mode
-f file
set the pcap file to read packets from
-http address
use http server and set the listen address (e.g.: :8000)
-i interface
set the interface to listen on
-interval seconds
set output interval to seconds (default 5)
-pcap-filter filter
set pcap packet filtering to filter
-pcap-promisc
set pcap promiscuous parameter (default true)
-pcap-snaplen bytes
set pcap snapshot length parameter to bytes (default 1024)
-pcap-timeout seconds
set pcap timeout parameter to seconds (default 1)
-peers
show peers
When listnd is running, it periodically prints the discovered devices and information it was able to gather about them to the console.
Running listnd on a small home network for a short period:
$ sudo ./listnd -i eth3
[...]
======================================================================
Devices: 2 (pkts: 5246)
======================================================================
MAC: 5c:49:79:fe:dc:ba (age: 1, pkts: 3317)
Properties:
Router: true (age: 122)
Powerline: true (age: 2)
Unicast Addresses:
IP: 2001:c0ff:eec0:ffee:5e49:79ff:fefe:dcba (age: 93, pkts: 1)
IP: fe80::5e49:79ff:fefe:dcba (age: 52, pkts: 1)
IP: 192.168.1.1 (age: 87, pkts: 12)
Multicast Addresses:
IP: 224.0.0.251 (age: -1, pkts: 0)
IP: 224.0.0.22 (age: -1, pkts: 0)
IP: 224.0.0.2 (age: -1, pkts: 0)
IP: 239.255.255.250 (age: -1, pkts: 0)
IP: 224.0.0.252 (age: -1, pkts: 0)
MAC: 70:85:c2:ab:cd:ef (age: 1, pkts: 1929)
Unicast Addresses:
IP: 192.168.1.23 (age: 1, pkts: 1842)
IP: fe80::7285:c2ff:feab:cdef (age: 52, pkts: 5)