Hi, I found a few messages in the archive that mention multi path and ECMP but the website says it's TODO. I was just wondering what the status is? I'm interested in having BIRD configure the Linux routing table for ECMP, if possible. Thanks, -Shaun
2015-12-14 23:02 GMT+08:00 Shaun Crampton <Shaun.Crampton@metaswitch.com>:
Hi,
I found a few messages in the archive that mention multi path and ECMP but the website says it's TODO. I was just wondering what the status is? I'm interested in having BIRD configure the Linux routing table for ECMP, if possible.
Thanks,
-Shaun
I am curious about this topic also. several years ago I use bird 1.4 + ospf ecmp at linux 2.6 (rehl6 and openwrt AA), they work quite well so I don't think much about it. recently I try bird 1.4.5 + ospf ecmp at linux 3.10/3.16 (rhel7 and openwrt CC), they work very bad. after study I realize it's because linux kernel 3.6 remove routing cache. but the situation may get better since the new patch get merged in kernel 4.4 https://lwn.net/Articles/657431/ I have heard that bird 1.5 get some new functions about ecmp, but I can not find out what are them. can anybody give some hint about what's new in bird ecmp?
Part of the problem is the kernel. The other part is BGP multipath. I've offered to sponsor its development, but the maintainers of bird aren't interested. On Mon, Dec 14, 2015 at 6:31 PM, d tbsky <tbskyd@gmail.com> wrote:
2015-12-14 23:02 GMT+08:00 Shaun Crampton <Shaun.Crampton@metaswitch.com>:
Hi,
I found a few messages in the archive that mention multi path and ECMP but the website says it's TODO. I was just wondering what the status is? I'm interested in having BIRD configure the Linux routing table for ECMP, if possible.
Thanks,
-Shaun
I am curious about this topic also. several years ago I use bird 1.4 + ospf ecmp at linux 2.6 (rehl6 and openwrt AA), they work quite well so I don't think much about it. recently I try bird 1.4.5 + ospf ecmp at linux 3.10/3.16 (rhel7 and openwrt CC), they work very bad. after study I realize it's because linux kernel 3.6 remove routing cache. but the situation may get better since the new patch get merged in kernel 4.4 https://lwn.net/Articles/657431/
I have heard that bird 1.5 get some new functions about ecmp, but I can not find out what are them. can anybody give some hint about what's new in bird ecmp?
On Mon, Dec 14, 2015 at 6:31 PM, d tbsky <tbskyd@gmail.com> wrote:
2015-12-14 23:02 GMT+08:00 Shaun Crampton <Shaun.Crampton@metaswitch.com>:
Hi,
I found a few messages in the archive that mention multi path and ECMP but the website says it's TODO. I was just wondering what the status is? I'm interested in having BIRD configure the Linux routing table for ECMP, if possible.
I have heard that bird 1.5 get some new functions about ecmp, but I can not find out what are them. can anybody give some hint about what's new in bird ecmp?
On Mon, Dec 14, 2015 at 06:38:49PM -0800, kris wrote: Part of the problem is the kernel. The other part is BGP multipath. I've offered to sponsor its development, but the maintainers of bird aren't interested.
Hi IPv4 ECMP for OSPF and static routes is supported since long ago. IPv4 ECMP for RIP is supported since v1.5.0. IPv4 BGP multipath is supported in master branch in devel tree (commit 8d9eef17713a9b38cd42bd59c4ce76c3ef6c2fc2). IPv6 ECMP is currently not supported. There also may be problems in kernel multipath forwarding unrelated to BIRD (as mentioned by d tbsky). -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santiago@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."
On 12/15/2015 6:41 AM, Ondrej Zajicek wrote:
On Mon, Dec 14, 2015 at 6:31 PM, d tbsky <tbskyd@gmail.com> wrote:
2015-12-14 23:02 GMT+08:00 Shaun Crampton <Shaun.Crampton@metaswitch.com>:
Hi,
I found a few messages in the archive that mention multi path and ECMP but the website says it's TODO. I was just wondering what the status is? I'm interested in having BIRD configure the Linux routing table for ECMP, if possible. I have heard that bird 1.5 get some new functions about ecmp, but I can not find out what are them. can anybody give some hint about what's new in bird ecmp? On Mon, Dec 14, 2015 at 06:38:49PM -0800, kris wrote: Part of the problem is the kernel. The other part is BGP multipath. I've offered to sponsor its development, but the maintainers of bird aren't interested. Hi
IPv4 ECMP for OSPF and static routes is supported since long ago.
IPv4 ECMP for RIP is supported since v1.5.0.
IPv4 BGP multipath is supported in master branch in devel tree (commit 8d9eef17713a9b38cd42bd59c4ce76c3ef6c2fc2).
IPv6 ECMP is currently not supported. There also may be problems in kernel multipath forwarding unrelated to BIRD (as mentioned by d tbsky).
Does BIRD handle sending ECMP routes via BGP? With 1.5.0, even if I enable 'add paths on', BIRD only sends one route even when it knows about multiple. To me, 8d9eef17713a9b38cd42bd59c4ce76c3ef6c2fc2 only appears to be related to populating the kernel routing table here, which I'm not using.
On Tue, Dec 15, 2015 at 10:33:30AM -0500, Brian Rak wrote:
Does BIRD handle sending ECMP routes via BGP? With 1.5.0, even if I enable 'add paths on', BIRD only sends one route even when it knows about multiple. To me, 8d9eef17713a9b38cd42bd59c4ce76c3ef6c2fc2 only appears to be related to populating the kernel routing table here, which I'm not using.
I am not sure whether i understand the question. If you have multiple routes and ADD-PATH enabled on both sides, then all routes are propagated. If you have one route with ECMP next hop, it is propagated as one route in BGP (regardless of ADD-PATH). In which use case are you interested? -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santiago@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."
On Tue, Dec 15, 2015 at 12:41:11PM +0100, Ondrej Zajicek wrote:
Hi
IPv4 ECMP for OSPF and static routes is supported since long ago.
IPv4 ECMP for RIP is supported since v1.5.0.
This is a mistake, IPv4 ECMP for RIP is also in GIT master branch, not in v1.5.0
IPv4 BGP multipath is supported in master branch in devel tree
-- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santiago@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."
On 15/12/2015 12:41 μμ, Ondrej Zajicek wrote:
On Mon, Dec 14, 2015 at 6:31 PM, d tbsky <tbskyd@gmail.com> wrote:
2015-12-14 23:02 GMT+08:00 Shaun Crampton <Shaun.Crampton@metaswitch.com>:
Hi,
I found a few messages in the archive that mention multi path and ECMP but the website says it's TODO. I was just wondering what the status is? I'm interested in having BIRD configure the Linux routing table for ECMP, if possible.
I have heard that bird 1.5 get some new functions about ecmp, but I can not find out what are them. can anybody give some hint about what's new in bird ecmp?
On Mon, Dec 14, 2015 at 06:38:49PM -0800, kris wrote: Part of the problem is the kernel. The other part is BGP multipath. I've offered to sponsor its development, but the maintainers of bird aren't interested.
Hi
IPv4 ECMP for OSPF and static routes is supported since long ago.
IPv4 ECMP for RIP is supported since v1.5.0.
IPv4 BGP multipath is supported in master branch in devel tree (commit 8d9eef17713a9b38cd42bd59c4ce76c3ef6c2fc2).
But, the kernel will balance the traffic to multiple next hops, right ? We use resilient ECMP on Arista( a close implementation mentioned in RFC2991, RFC2992) and was looking to simply run Bird on Linux to achieve the same. Cheers, Pavlos
participants (6)
-
Brian Rak -
d tbsky -
kris -
Ondrej Zajicek -
Pavlos Parissis -
Shaun Crampton