Re: Multi-home II

["Daniel L. Golding" <dan () netrail net>]

On Sun, 14 May 2000, Alex Bligh wrote:

> > > Can you please help point out a good may to multi-home?
> > > I would like to get a site put in a Co-lo in the west coast
> > > and one in the east coast.  Both would be different co-lo's.
> > > Could I get a single ASN and handle both places with different
> > > subnets under the same ASN?
>
> Yes but it's kludgy as your West coast router's BGP loop
> detection algorithm will cause it to ignore the routes
> to your East coast colo that are heard from your West coast
> upstream. You can fix this, for instance, by defaulting
> to a network originated by your upstream.
> I am assuming you send different subnets to your
> upstream(s) at either site; if both subnets together form
> a supernet and you use the same upstream, you can also send
> that same supernet from both East and West coasts and mark
> the subnets no-export which should (a) save on prefixes and
> (b) mean your advertized route is larger and less likely
> to get filtered / damped.

An aggregate address announcement by your upstream would also do this
quite nicely...


[snip]
> -- 
> Alex Bligh
> VP Core Network, Concentric Network Corporation
> (formerly GX Networks, Xara Networks)