Re: [IPv6] PROBLEM? Network unreachable despite correct route

Bernhard Schmidt
2007-01-11T13:08:23Z

Jarek Poplawski wrote:

>> ip -6 route:
>> 2001:4ca0:0:f000::/64 dev eth0 proto kernel metric 256 expires 86322sec mtu 1500 advmss 1440 fragtimeout 4294967295
>> fe80::/64 dev eth0 metric 256 expires 21225804sec mtu 1500 advmss 1440 fragtimeout 4294967295
>> ff00::/8 dev eth0 metric 256 expires 21225804sec mtu 1500 advmss 1440 fragtimeout 4294967295
>> default via fe80::2d0:4ff:fe12:2400 dev eth0 proto kernel metric 1024 expires 1717sec mtu 1500 advmss 1440 fragtimeout 64
>> unreachable default dev lo proto none metric -1 error -101 fragtimeout 255
> Did you analyze this dev lo warning?

That one is default. Recent kernels (since 2.6.12 or so, I think when
the default on-link assumption was killed) have a default route pointing
to "unreachable default lo" on bootup. Routes learned from RA or added
statically are installed with a better metric and are preferred that way.

I think the use is to have a Network unreachable returned immediately if
no IPv6 router is present.

Regards,
Bernhard