carp backup host replies to arp-request

[Kazuaki Oda]

Gleb Smirnoff wrote:
>   Kazuaki-san,
> 
> On Thu, Nov 17, 2005 at 03:22:39PM +0900, Kazuaki Oda wrote:
> K> I have set up 2 routers with FreeBSD 6.0-RELEASE.  They are using carp
> K> interfaces, so one is a master router and another is a backup.
> K> They seemed to work fine, but a few days later I noticed that not only
> K> master router but also backup router replies to arp-requests of the
> K> common IP address from a layer 3 switch.  This behavior confuses the
> K> switch, and sometimes it makes the switch to send a packet addressed
> K> to the common IP address to the port which is connected to backup router.
> K> I googled and found that OpenBSD fixed this problem in ip_carp.c 1.62.
> K> I hope that someone import this into FreeBSD...
> 
> Can you please confirm, that the attached patch fixes the problem for you?

Yes!  I just modified the patch (because I am using 6.0-RELEASE
replaced IF_LLADDR to IFP2ENADDR), applied the patch, rebuilded kernel
and rebooted the system.  So I get no arp-reply from backup router.
Layer 3 switch never sends packets to backup router.

Thanks.


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Kazuaki Oda