[CentOS] IPv6 on Centos 6

Mon Aug 13 18:05:16 UTC 2012
Alan Batie <alan at peak.org>

On 8/11/12 2:17 AM, James Hogarth wrote:

> With ipv6 in the picture stop using net-tools - they were deprecated a long
> time ago and there's multiple edge cases and bugs where they don't work
> properly or lack features... learn to use the iproute2 toolset - ip, ss and
> tc being the key ones.

Love gratuitous changes to long standard toolsets... sigh...

> And it's ip -6 route not ip -6 router... or ip -6 r s in short ;-)

You're right, sorry, it was late on Friday ;-)

<centos666.peak.org> [50] # ip -6 r
unreachable ::/96 dev lo  metric 1024  error -101 mtu 16436 advmss 16376
hoplimit 4294967295
unreachable ::ffff:0.0.0.0/96 dev lo  metric 1024  error -101 mtu 16436
advmss 16376 hoplimit 4294967295
unreachable 2002:a00::/24 dev lo  metric 1024  error -101 mtu 16436
advmss 16376 hoplimit 4294967295
unreachable 2002:7f00::/24 dev lo  metric 1024  error -101 mtu 16436
advmss 16376 hoplimit 4294967295
unreachable 2002:a9fe::/32 dev lo  metric 1024  error -101 mtu 16436
advmss 16376 hoplimit 4294967295
unreachable 2002:ac10::/28 dev lo  metric 1024  error -101 mtu 16436
advmss 16376 hoplimit 4294967295
unreachable 2002:c0a8::/32 dev lo  metric 1024  error -101 mtu 16436
advmss 16376 hoplimit 4294967295
unreachable 2002:e000::/19 dev lo  metric 1024  error -101 mtu 16436
advmss 16376 hoplimit 4294967295
2607:f678::/64 dev eth0  proto kernel  metric 256  mtu 1500 advmss 1440
hoplimit 4294967295
unreachable 3ffe:ffff::/32 dev lo  metric 1024  error -101 mtu 16436
advmss 16376 hoplimit 4294967295
fe80::/64 dev eth0  proto kernel  metric 256  mtu 1500 advmss 1440
hoplimit 4294967295
default via 2607:f678::1 dev eth0  metric 1  mtu 1500 advmss 1440
hoplimit 4294967295

Also love quality error messages "-101" is *sooo* informative ;-)

But the last line should be the important one and shows the proper
default route in place, though the even more important one is the route
to the local net (2607:f678::/64) which also looks right.  It's not a
routing issue, it's a neighbor discovery issue:

<centos666.peak.org> [55] # ip neigh show
2607:f678::1 dev eth0  FAILED
207.55.16.1 dev eth0 lladdr 00:26:88:f2:9e:80 REACHABLE