Re: ARP routing issue

[Jan De Luyck <lkml@kcore.org>]

On Friday 07 January 2005 08:44, Julian Anastasov wrote:
>  Hello,
>
> On Thu, 6 Jan 2005, Jan De Luyck wrote:
> > http://www.uwsg.iu.edu/hypermail/linux/net/0308.1/0071.html
> >
> > Basically it comes down to this:
> >
> > I have an IBM server running RH ES, kernel 2.4.9-e.49. It has two
> > interfaces: eth0 10.0.22.xxx
> > eth1 10.0.24.xxx
> >
> > default gateway is set to 10.0.22.1, on eth0.
> >
> > Problem is, if I try to ping from another network (10.216.0.xx) to
> > 10.0.24.xx, i see the following ARP request:
> >
> > arp who-has 10.0.22.1 tell 10.0.24.xx
> >
> > which, imo, is wrong.
> >
> > I know it has to do with the default gatway, but I can't devise a way to
> > make it actually _WORK_.
>
>  Not wrong but it is one of the possible valid requests. 

Yes, I've gathered that. Yet, it seems very strange, and I want to _change_ 
that behaviour.

>  If it 
> is ignored from other boxes in your setup then you can look
> at new kernels. 2.4.26 and 2.6.4 come with new sysctl flags for ARP.
> arp_filter filters incoming requests but you can use arp_announce to
> control the source IP when sending requests, eg. in IBM server you can set
> /proc/sys/net/ipv4/conf/eth*/arp_announce to 1 or 2 or even just
> /proc/sys/net/ipv4/conf/all/arp_announce to 1 or 2

Hmm. Point is, for certification/support reasons we'd rather stick to the 
RedHat ES supplied kernels instead of starting off with one of our own. I 
can't go off running non-checked-to-be-stable (in a business POV) code on 
mission-critical systems. (2.6.10 is stable enough in _my_ POV, but well..)

Jan

-- 
Serfs up!
  -- Spartacus