Archive for June, 2015

Stupid IPv6 Tricks

Monday, June 22nd, 2015

Today, I was given a VM with an IPv6 address, but it had no IPv6 default route:

$ route -A inet6
Kernel IPv6 routing table
Destination Next Hop Flags Metric Ref Use Iface
2001:db8:80:fd::/64 * U 256 1 0 eth1
fe80::/64 * U 256 0 0 eth1
localhost/128 * U 0 48 1 lo
2001:db8:80:fd::67:8/128 * U 0 77 1 lo
fe80::a00:32ff:feb7:73cd/128 * U 0 53 1 lo
ff00::/8 * U 256 0 0 eth1

Sadness.

I was also not given the router I needed to set the default route to. But no fear, we can ping the router multicast address!

$ ping6 ff02::2 -I eth1 -c1
PING ff02::2(ff02::2) from fe80::a00:32ff:feb7:73cd eth1: 56 data bytes
64 bytes from fe80::a00:32ff:fe4f:9ebc: icmp_seq=1 ttl=64 time=0.411 ms
--- ff02::2 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.411/0.411/0.411/0.000 ms

And all is solved!

# route -A inet6 add default gw fe80::a00:43ff:fe4f:9ebc dev eth1
$ route -A inet6
Kernel IPv6 routing table
Destination Next Hop Flags Metric Ref Use Iface
2001:db8:80:fd::/64 * U 256 1 0 eth1
fe80::/64 * U 256 0 0 eth1
*/0 fe80::a00:32ff:fe4f:9ebc UG 1 0 0 eth1
localhost/128 * U 0 48 1 lo
2001:db8:80:fd::67:8/128 * U 0 77 1 lo
fe80::a00:32ff:feb7:73cd/128 * U 0 53 1 lo
ff00::/8 * U 256 0 0 eth1
$ ping6 facebook.com -c1
PING facebook.com(edge-star6-shv-12-frc3.facebook.com) 56 data bytes
64 bytes from edge-star6-shv-12-frc3.facebook.com: icmp_seq=1 ttl=48 time=163 ms
--- facebook.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 163.953/163.953/163.953/0.000 ms

And there was much rejoicing!


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