On 2008-10-08, Stuart Henderson <[EMAIL PROTECTED]> wrote: > On 2008-10-08, BARDOU Pierre <[EMAIL PROTECTED]> wrote: >> This is a multi-part message in MIME format. >> >> ------=_NextPart_000_00C3_01C92936.6DEF4560 >> Content-Type: multipart/mixed; >> boundary="----=_NextPart_001_00C4_01C92936.6DEF4560" >> >> >> ------=_NextPart_001_00C4_01C92936.6DEF4560 >> Content-Type: text/plain; >> charset="iso-8859-1" >> Content-Transfer-Encoding: quoted-printable > > Ugh, I thought the list server stripped these. Did something change? > >> The problem is that if the ISP router fails, my corresponding BGP=20 >> router is still up and running, and so keeps the CARP master,=20 >> which makes him a black hole :( > > I don't think I'd do it like this (either preferring OSPF running > on BGP speakers to distribute default routes, or iBGP to avoid > handing traffic to one router only to hand it straight to the other > one). But it can be done, look at "demote". > >
Oh, in case it wasn't clear, you also need to write the bgpd.conf parts to handle route selection. As Claudio says, just the standard traffic engineering methods. Investigate localpref, prepend-neighbor, weights, etc. There is no magic "balance my traffic" button. See http://quigon.bsws.de/papers/epf2006/mgp00012.html. As you hopefully know, balacing incoming traffic is a different matter. Return packets do not automatically come in via the ISP where you sent the associated outbound packets. For this, look at prepends and whether your upstreams give you any finer control over traffic-engineering via communities (for an example of what some providers let you do, see e.g. "whois -r as3356", in the "Communities accepted from customers" section). If you are learning this whole area, you have some reading to do. Plenty of information is available online and in print. Much of it is aimed at cisco users and you'll need to read between the lines for any !cisco, but the basic information and techniques are generally applicable.
