A quick note / command snippet for filtering ICMPv6 packets when troubleshooting IPv6 autoconfiguration.
# tcpdump -i eth0 -v '(icmp6 && ip6[40] == 134) or (icmp6 && ip6[40] == 133) or (icmp6 && ip6[40] == 135) or (icmp6 && ip6[40] == 136)'
The most common ICMPv6 types are:
- unreachable: 1
- too-big: 2
- time-exceeded: 3
- echo-request: 128
- echo-reply: 129
- router-solicitation: 133
- router-advertisement: 134
- neighbor-solicitation: 135
- neighbor-advertisement: 136
