From: Andre Teku (andre.teku@xxxxxxxxx)
Date: Wed Jul 24 2002 - 12:19:05 GMT-3
If you are a stub (as opposed to a transit) do this:
1. Announce your aggregate or block of addresses to both ISPs but,
2. On the backup link announce your AS with a longer path length (use the
prepend command) to make it less desirable
3. Take default route announcements from both ISPs but
4. On the backup link entry point assign a lower "Local Preference" value to
the default route to make it unattractive
5. Don't take full routes and all that unless you want to optimize
neighborhood routing
Good luck
Andre
-----Original Message-----
From: Carlos G Mendioroz [mailto:tron@huapi.ba.ar]
Sent: Wednesday, July 24, 2002 9:57 AM
To: Scooby Dooby
Cc: ccielab@groupstudy.com
Subject: Re: OT: Multihoming to two ISP's
What ?
Scooby Dooby wrote:
>
> A quick input:
>
> Wihtout running BGP and playing with the BGP attributes(Local pref,Med and
> AS pre-pending), it would be unwise to advertise the same route through
two
> different ISP's.
> It would cause routing loops ,
> as the world would have only one way to reach the main advertised services
> like(Web,DNS,WEB) .Only ISP or company registered with IANA and
> RIR(regional registration authority)would be preferred to pass the traffic
> to the end host.
>
> Cheers,
> OK.
>
> >From: Carlos G Mendioroz <tron@huapi.ba.ar>
> >Reply-To: Carlos G Mendioroz <tron@huapi.ba.ar>
> >To: ccielab@groupstudy.com
> >Subject: Re: OT: Multihoming to two ISP's
> >Date: Wed, 24 Jul 2002 07:22:17 -0300
> >
> >Conditional advertisement seems to be the only reliable way for
> >directing
> >all incomming traffic throw one link. And it also serves well the health
> >of the core routers :-)
> >
> >
> >
> >roel.fonteyn@belgacom.be wrote:
> > >
> > > Did you try AS prepending, to reduce the chance other providers
taking
> >this route?
> > >
> > > Mvg/Rgrds,
> > >
> > > Roel
This archive was generated by hypermail 2.1.4 : Sat Sep 07 2002 - 19:36:42 GMT-3