[Gllug] arp problem?

[John Winters]

On Sun, 2006-06-11 at 12:36 +0100, Adrian McMenamin wrote:
> On Sun, 2006-06-11 at 03:28 +0100, Casper Gasper wrote:
> > On 10/06/06, Adrian McMenamin <adrian at mcmen.demon.co.uk> wrote:
> > > I have a network card (eth0) attached to this (Ubuntu) box which has a
> > > crossover cable connection to one other device.
> > >
> > > I assign the attached device's IP addr using arp - I have this in
> > > rc.local:
> > >
> > > arp -s 192.168.61.55 00:d0:f1:03:12:b9
> > 
> >   Why do you need to put a static entry in the arp table?
> > 
> What is the alternative? (Seriously).

The alternative (normal) way is just to let the boxes discover MAC
addresses using the ARP mechanism.  The conversation goes something like
this:

1st box (shouting): Anyone out there got IP address XX.XX.XX.XX?
2nd box:            Yup.  That's me.

Both boxes then cache the MAC address of the other in their arp caches
and the subsequent conversation continues much more quietly.

It's only if you're doing something a bit odd that you need to pre-load
the arp cache with MAC addresses.

HTH
John

-- 
John Winters, Wallingford, Oxon, England
i = (free (NULL); i++);

-- 
Gllug mailing list  -  Gllug at gllug.org.uk
http://lists.gllug.org.uk/mailman/listinfo/gllug