Netlink: File exists

[Ondrej Zajicek]

On Tue, Feb 02, 2010 at 06:57:14PM +0000, Chris Webb wrote:
> This seems to work fine, apart from the message "bird: Netlink: File exists"
> appearing in syslog every minute. My routing table before starting bird
> looks like this
> 
>   # ip route show
>   84.45.39.148/30 dev eth1  proto kernel  scope link  src 84.45.39.150 
>   91.203.56.0/23 dev eth0  proto kernel  scope link  src 91.203.57.1
>   default via 84.45.39.149 dev eth1 
> 
> in case this is related to bird being unable to overwrite the existing
> static routes?


Yes, the behavior is that BIRD will ignore existing 'alien' routes and can't
overwrite them. As routes in kernel routing table have protocol tag
specifying who added such route, we remove 'our' unexpected routes (for
example, if BIRD is killed and restarted), but ignore 'alien' routes.

But this explanation of error message "Netlink: File exists" would assume
that you receive default route wia BGP, which is not usual.

I would like to add a option allowing BIRD to remove 'alien' routes,
but it is not here yet. It can be workarounded by creating static
routes with 'bird' tag, like:

ip r a 192.168.210.0/24 via 192.168.1.45 protocol bird

> Also, I needed 
> 
>   sysctl net.core.rmem_max=524284
> 
> before starting quagga to avoid netlink "recvmsg overrun" messages and
> occasional loss of prefixes. Am I right in assuming that bird will need the
> same thing for the same reason?

I don't know about such requirement.

-- 
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."
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: Digital signature
URL: <http://trubka.network.cz/pipermail/bird-users/attachments/20100202/1adf10a1/attachment-0001.asc>