[52601] in North American Network Operators' Group
Re: iBGP next hop and multi-access media
daemon@ATHENA.MIT.EDU (Alex Rubenstein)
Mon Oct 7 00:34:56 2002
Date: Mon, 7 Oct 2002 00:34:39 -0400 (Eastern Daylight Time)
From: Alex Rubenstein <alex@nac.net>
To: Ralph Doncaster <ralph@istop.com>
Cc: "nanog@merit.edu" <nanog@merit.edu>
In-Reply-To: <Pine.LNX.4.21.0210070026070.3597-100000@ns.istop.com>
Errors-To: owner-nanog-outgoing@merit.edu
Aha.
So, if you route to a ethernet interface, it will try to arp for that
address on that subnet, even without having a local address on the same
subnet?
This seems to me to be something you don't want to do.
Is the entire route valid as long as the router can ARP for one of the
addresses in the routed subnet?
On Mon, 7 Oct 2002, Ralph Doncaster wrote:
> On Mon, 7 Oct 2002, Alex Rubenstein wrote:
>
> > I've been doing ip route statements going on 8 years now, and I can't
> > imagine why ever -- and how it would even work -- you'd want to ip route a
> > netblock with a next hop of a multi-access brandcast media. As in, the
> > next hop is still truly undetermined.
> >
> > I guess I don't know this because I've never tried it. But, how does the
> > router determine where to send the packets for a route statement as
> > specified above (ip route a.b.c.d e.f.g.h f0/0) ?
>
> When you setup a secondary ip on an interface
> int fa0/0
> ip address a.b.c.d e.f.g.h secondary
>
> How does it determine where to send the packets? ARP.
> Which is the same as adding the route described above.
>
> -Ralph
>
-- Alex Rubenstein, AR97, K2AHR, alex@nac.net, latency, Al Reuben --
-- Net Access Corporation, 800-NET-ME-36, http://www.nac.net --
