IPv6 multipath static routes with different weights and BFD supervision

[Ondrej Zajicek]

On Mon, Jan 22, 2018 at 03:39:06PM +0000, ?????? ?????????? wrote:
> Hi BIRD experts,
> I face some problems on static routes on IPv6. I try to configure multipath static routes that are supervised with BFD. I use the following conf:
> route <DEST_IPv6> multipath
>         via <NEXT_HOP1_IPv6> weight 10 bfd
>         via <NEXT_HOP2_IPv6> weight 20 bfd;
> This does not seem to have the expected behavior since I notice that the static routes are configured with the same priority rather than having the less weighted one with higher priority than the more weighted.
> When I try to check the routes passed to the kernel I notice this:
> <DEST_IPv6> via <NEXT_HOP1_IPv6> dev eth3  proto bird  metric 1024
> <DEST_IPv6> via <NEXT_HOP2_IPv6> dev eth5  proto bird  metric 1024
> The same configuration for IPv4 works as expected...
> could you, please, give me some initial orientation regarding the issue?

Hi

I think that older kernels (ones that report IPv6 ECMP routes as multiple
routes) do not support weight for IPv6. On Jessie, i cannot set IPv6
weighted ECMP even using 'ip route add'.

Not sure about newer kernels. BIRD uses older IPv6-ECMP API for route
changes (to be compatible with older kernels), so we do not support
weight here neither.

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
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"To err is human -- to blame it on a computer is even more so."