Changing ECMP weight on OSPF routes with an ingress filter
Hi, I have a setup with some routers: +----------------+ +----------------+ +---------------+ | close router 1 | | close router 2 | | far router | | 45.91.126.233 | | 45.91.126.236 | | 45.91.126.235 | +----------------+ +----------------+ +---------------+ \ | / | \ +-------------+/ +---------------+ \| core router | | other routers | +-------------+ +---------------+ Each edge router announces a default to my core router, and I have ECMP to balance the traffic. bird> show route all 0.0.0.0/0 Table master4: 0.0.0.0/0 unicast [ospf_ipv4 12:15:31.798] I (150/30) [89.234.186.31] via 45.91.126.233 on tinc0 weight 1 via 45.91.126.235 on tinc0 weight 1 via 45.91.126.236 on tinc0 weight 1 Type: OSPF univ I tried to change ecmp_weight on the ospf import filter matching the router ID, but I have this message: “/etc/bird.conf:81:22 Symbol `ecmp_weight' is read-only.” I don’t want to change the weight on the far router as there are other routers to have their default on 45.91.126.233 and 45.91.126.236. I can’t change the cost on the link as it’s the same L2 viewed from the core router. Is there a simple mean to achieve this or is it a better idea to switch to BGP? Thanks, -- Alarig
On Wed, Nov 13, 2019 at 06:38:09PM +0100, Alarig Le Lay wrote:
Hi,
bird> show route all 0.0.0.0/0 Table master4: 0.0.0.0/0 unicast [ospf_ipv4 12:15:31.798] I (150/30) [89.234.186.31] via 45.91.126.233 on tinc0 weight 1 via 45.91.126.235 on tinc0 weight 1 via 45.91.126.236 on tinc0 weight 1 Type: OSPF univ
I tried to change ecmp_weight on the ospf import filter matching the router ID, but I have this message: “/etc/bird.conf:81:22 Symbol `ecmp_weight' is read-only.”
Hi We currently do not support changing properties of specific nexthops (limitation of BIRD-script). You can configure per-interface weight in OSPF, but that probably does not help in your case (as they are all in tinc0). -- 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."
Hi, On 18/11/2019 16:04, Ondrej Zajicek wrote:
On Wed, Nov 13, 2019 at 06:38:09PM +0100, Alarig Le Lay wrote:
Hi,
bird> show route all 0.0.0.0/0 Table master4: 0.0.0.0/0 unicast [ospf_ipv4 12:15:31.798] I (150/30) [89.234.186.31] via 45.91.126.233 on tinc0 weight 1 via 45.91.126.235 on tinc0 weight 1 via 45.91.126.236 on tinc0 weight 1 Type: OSPF univ
I tried to change ecmp_weight on the ospf import filter matching the router ID, but I have this message: “/etc/bird.conf:81:22 Symbol `ecmp_weight' is read-only.”
Hi
We currently do not support changing properties of specific nexthops (limitation of BIRD-script). You can configure per-interface weight in OSPF, but that probably does not help in your case (as they are all in tinc0).
Thanks for the clarification! I think that it will be easier to switch to BGP for now. Kind regards, -- Alarig
participants (2)
-
Alarig Le Lay -
Ondrej Zajicek