How to enable ECMP flow based forwarding ?

Andrey V. Elsukov bu7cher at
Tue Feb 14 14:15:19 UTC 2017

On 14.02.2017 03:23, Olivier Cochard-Labbé wrote:
> Hi,
> I'm testing FreeBSD ECMP behavior by adding "options RADIX_MPATH" to my
> kernel configuration (11-stable).
> Now I can configure two identical routes toward 2 different next-hop: First
> step achieved :-)
> But it uses only the first entry and never uses the second one.
> I've tried to shutdown the first next-hop router (then no more arp-reply
> from this next-hop): But the ECMP FreeBSD router sticks to its first route
> entry and never try the second entry :-(
> Is there something else to enable (like RSS?) for having a real ECMP flow
> based router ?

I think you need to implement some code first. The fastfwd has not
supported MPATH and tryforward also doesn't support it. For IPv4 you can
try to add some IPsec security policy to disable ip_tryforward. In this
case ip_forward() will be used, and it uses rtalloc_mpath_fib(), so,
probably, it will work.

WBR, Andrey V. Elsukov

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 553 bytes
Desc: OpenPGP digital signature
URL: <>

More information about the freebsd-net mailing list