IPv4 route via IPv6 next hop: Netlink: Network unreachable

Ondrej Zajicek santiago at crfreenet.org
Wed Apr 1 15:51:15 CEST 2020

On Wed, Apr 01, 2020 at 02:56:54PM +0200, Nico Schottelius wrote:
> Hello,
> I'm running 2.0.7 on Linux 5.4.18-0-lts (Alpine)
> and I receive the route from
> 2a0a:e5c0:1:9::2. However it is never set into the kernel, with the
> error message "Netlink: Network unreachable" in syslog.
> Has anyone seen this problem recently? I'm not sure if this is really a
> bird2 problem or not, to be honest:


BIRD 2.0.7 does not support properly putting IPv4 routes with IPv6 next
hops to kernel, you can try git master branch (or apply commit
53401bef63013dfee01b65d071ffbd88e457539f to v2.0.7). Or wait for 2.0.8,
which will be released hopefully this month.

> The kernel reports many messages like this in dmesg:
> [4541983.369058] netlink: 'bird': attribute type 5 has an invalid length.
> However, I am also puzzled that manually adding the route seems to fail:

Probably older iproute2 tools?

Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."

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