[c-nsp] which IGRP?

[Jeff Chan]

On Friday, July 15, 2005, 5:30:28 AM, Mark Tinka wrote:
> On Friday 15 July 2005 13:02, Jeff Chan wrote:

>> Instead of iBGP, should we use a routing protocol
>> optimized specifically for interior use such as EIGRP,
>> OSPF, etc.? Or can it be done satisfactorily with iBGP
>> and a route reflector setup?  (Naturally we're talking
>> eBGP to our external peers.)
>>
>> Is there a standard practice for this?

> I wouldn't say it's a standard practice, per se, but most 
> providers now do what you're doing, use iBGP as the IGP, 
> but different from what you are doing, use a "real" IGP, 
> e.g., OSPF or IS-IS, to create an infrastructure atop 
> which iBGP can create it's sessions. iBGP isn't 
> link-state, so it needs another routing protocol to tell 
> it how to get to its neighbors.

> In your case, although you don't mention it, it sounds 
> like you create your infrastructure with static routes, 
> which is how iBGP then creates its relationships. This 
> fine, for a small, beginning network, but as you grow 
> (which is what you are doing with a third router), 
> moving your static routing to something like OSPF or 
> IS-IS is the way to go.

> Keeping iBGP as your interior routing protocol would 
> still be personally recommended. As an IGP to begin 
> with, I'd recommend OSPF.

> Mark.

Thanks Mark and others so far.  Mark's explanation makes good
sense; we are currently using static routes to make the loopback
addresses reachable between routers, then we are iBGP peering
between loopback addresses.  Using something like OSPF to share
routing information about the internal network (instead of static
routes between routers) makes a lot of sense.

Cheers,

Jeff C.
-- 
Jeff Chan
mailto:cisco-nsp at jeffchan.com
http://www.supranet.net/