[20463] in North American Network Operators' Group
Re: BGP as an IGP (Was Re: IGPs in use)
daemon@ATHENA.MIT.EDU (Sean M. Doran)
Wed Oct 14 04:57:46 1998
From: "Sean M. Doran" <smd@clock.org>
To: chrisy@flix.net, nanog@merit.edu, pdonner@cisco.com
Date: Wed, 14 Oct 1998 01:45:31 -0700
Chrisy Luke wrote:
| Paul G. Donner wrote (on Oct 13):
| > If BGP rides on TCP, how are the TCP sessions built if BGP itself is used
| > as the IGP?
|
| Same way as it does when you take next-hops from any other IGP. The fact
| that one already has a route to ones' directly attached networks.
In other words, the interior routing protocol is either static
or a combination of statically configured routes and the likes
of ARP/ES-IS/other neighbour discovery protocols.
The key point is that, in a router talking iBGP, the route to the
NEXT_HOP received by an iBGP neighbour *MUST* be known through
means other than BGP. This is not to say that the route need
be dynamic -- a static default route would do just fine.
Sean.
