Gmail MX over IPv6

Bernhard Schmidt berni at
Thu Jun 21 09:32:56 CEST 2012

Am 21.06.2012 09:28, schrieb Mansoor Nathani:


> I noticed it seems to be picking up some ip / address info from an IPv6
> tunnel to Hurricane Electric.
> I never configured this host with any such IPv6 information however.
> The tunnel is using 2001:470:b148::/48 .

Well, someone in your network obviously did.

> 2001:470:b148::/48 dev eth0  proto kernel  metric 256  expires 0sec mtu
> default via fe80::205:32ff:fee8:8b61 dev eth0  proto kernel  metric 1024
>  expires 0sec mtu 1500 advmss 1440 hoplimit 64

The device with the MAC address 00:05:32:e8:8b:61 is sending router
advertisements with the prefix 2001:470:b148::/48 . Lucky (or unlucky)
for you they are wrongly advertising a /48, not a /64, so SLAAC does not
work and you don't get an address assigned. I'm a bit confused at the
moment, since I thought Linux was handling "has defaultroute but not a
global address" correctly these days, but obviously there are still some

Hunt down that bogus advertisement, that should solve the problem.


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