rajr0 / ndp

Package ndp implements the Neighbor Discovery Protocol, as described in RFC 4861. MIT Licensed.

ndp

Package ndp implements the Neighbor Discovery Protocol, as described in RFC 4861. MIT Licensed.

The command ndp is a utility for working with the Neighbor Discovery Protocol.

Install the package and utility using go get:

$ go get github.com/mdlayher/ndp/...

To learn more about NDP, and how to use this package, check out my blog: Network Protocol Breakdown: NDP and Go.

Examples

Listen for incoming NDP messages on interface eth0 to one of the interface's global unicast addresses.

$ sudo ndp -i eth0 -a global listen
$ sudo ndp -i eth0 -a 2001:db8::1 listen

Send router solicitations on interface eth0 from the interface's link-local address until a router advertisement is received.

$ sudo ndp -i eth0 -a linklocal rs

Send neighbor solicitations on interface eth0 to a neighbor's link-local address until a neighbor advertisement is received.

$ sudo ndp -i eth0 -a linklocal -t fe80::1 ns

An example of the tool sending a router solicitation and receiving a router advertisement on the WAN interface of a Ubiquiti router:

$ sudo ndp -i eth1 -a linklocal rs
ndp> interface: eth1, link-layer address: 04:18:d6:a1:ce:b8, IPv6 address: fe80::618:d6ff:fea1:ceb8
ndp rs> router solicitation:
    - source link-layer address: 04:18:d6:a1:ce:b8

ndp rs> router advertisement from: fe80::201:5cff:fe69:f246:
    - hop limit:        0
    - flags:            [MO]
    - preference:       0
    - router lifetime:  2h30m0s
    - reachable time:   1h0m0s
    - retransmit timer: 0s
    - options:
        - prefix information: 2600:6c4a:7002:100::/64, flags: [], valid: 720h0m0s, preferred: 168h0m0s