On Thu, Mar 15, 2007 at 03:08:07PM +0100, Ralph Passgang wrote:
> Hello,
>
> I noticed that our freewrt routers answer to arp request for ip adresses on
> all available interfaces, even if the requested ip is not bound to the
> interface where the request was recieved. This has nothing to do with vlans,
> furthermore this happens even for completely diffrent physical interfaces.
>
> in my case the IP 192.168.1.1 was configured on eth0.6, but even if I pinged
> 192.168.1.1 from an external system, that was connected to eth0.0, the box
> replied via arp on eth0.0, even if the ip isn't reachable via eth0.0 at all.
>
> This means that it is not possible to use the same IPs in diffrent VLANs or
> physical LANs at all without serious trouble.
>
> To disable this "feature" of arp-replying on all interfaces, it is possible to
> set arp_filter = 1 via the proc interface per interface or global for all
> interfaces.
>
> Even if the default linux behaviour is to repsond to arp request on all
> interfaces (arp_filter = 0) it might be more clever to enable this filter on
> all freewrt installations per default. It shouldn't break anything on a
> already working setup, but should help to reduce strange network errors that
> are hard to resolve, that might get caused without this filter.
>
> Waldemar told me, that he would like to enable this filter globally, so if no
> one protests about it, we will enable it for branch/1.0 in 5 days from now
> on.

Hi Ralph,

sounds logical to me. Perhaps you should make some tests with arp_ignore
as well, see
http://kb.linuxvirtualserver.org/wiki/Using_arp_announce/arp_ignore_to_disable_ARP.

Dirk
_______________________________________________
freewrt-developers mailing list
[email protected]
https://www.freewrt.org/lists/listinfo/freewrt-developers

Reply via email to