Re: [Znog] Problems when running zebra with OSPFD daemon

[Yasuhiro Ohara]

What you want is enable-multipath. Compile zebra with e.g.
--enable-multipath=2.

Because I haven't tested ospfd on Linux, I don't know if any other
tricks will be necessary. As far as I know, other platforms like
FreeBSD, NetBSD, OpenBSD it can't be done due to the fact that
they does not support ECMP feature on their kernel.
For other tricks which might be necessary,
please ask it on address@hidden

regards,
yasu

From: Santiago Najera <address@hidden>
Subject: [Znog] Problems when running zebra with OSPFD daemon
Date: Fri, 16 Apr 2004 10:54:09 +0200

> Hi:
> 
> We are experiencing problems when running OSPF as daemon, in fact, OSPF
> routes are not propagated to Kernel routing table. Let me explain the
> environment:
> 
> 
> -. We have 2 Zebra routers connectd with 2 ethernet interfaces per node (2
> links) and behind them there are 2 IP subnets to propagate
> 
> +----------+     +------+ link1 +------+      +----------+
> |          |     |      |-------|      |      |          |
> | subnet 1 |-----| node1|       | node2|------| subnet 2 |
> |          |     |      |-------|      |      |          |
> +----------+     +------+ link2 +------+      +----------+
> 
> -. We have configure OSPF using both links as balanced ("equalized" as
> specified in OSPF terminology), I mean, we need 2 routes to next hop using
> both links
> -. If we run OSPFD daemon from rc.local file (without login in system,
> invoking first "zebra -dl" and after "ospfd -d"), when checking routes using
> "show ip ospf route" 2 routes with same cost using each link to next hop
> appear in every node, but if we check them using "ip route list" (kernel ip
> routes) only appears one of them. So traffic balancing does not run. See
> example below:
> 
> 
> OSPF
> 
> address@hidden root]# ip route list
> 192.168.101.24/29 dev eth0  proto kernel  scope link  src 192.168.101.30 
> 192.168.101.32/29 dev eth1  proto kernel  scope link  src 192.168.101.38 
> 10.0.0.0/24 dev eth2  proto kernel  scope link  src 10.0.0.1 
> 10.0.1.0/24  dev eth0  proto kernel  scope link  src 192.168.101.25
> 127.0.0.0/8 dev lo  scope link 
> address@hidden root]#
> 
> 
> 
> -. If we manually run OSPFD from console (login previously as root in
> system) and we execute the commands above commented, both ip route tables
> (ospf and kernel are correct and show 2 routes as configured and needed. See
> example below:
> 
> OSPF
> 
> address@hidden root]# ip route list
> 192.168.101.24/29 dev eth0  proto kernel  scope link  src 192.168.101.30 
> 192.168.101.32/29 dev eth1  proto kernel  scope link  src 192.168.101.38 
> 10.0.0.0/24 dev eth2  proto kernel  scope link  src 10.0.0.1 
> 10.0.1.0/24  proto zebra  metric 30 equalize 
>         nexthop via 192.168.101.25  dev eth0 weight 1
>         nexthop via 192.168.101.33  dev eth1 weight 1
> 127.0.0.0/8 dev lo  scope link 
> address@hidden root]#
> 
> 
> We have reviewed permissions, Zebra compilation (with "enable-multipath=0"),
> kernel, etc. and we suspect there is a bug in daemon or any hidden feature
> that can solve the problem. Of course, manual executing is not a solution
> due to the equipment will be installed as unattended.
> We have LINUX Red Hat 7.3 and I `m using  quagga-0.96.4.
> 
> Best regards,
> Santiago
> 
> 
> 
> 
> 
> 
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