nanog mailing list archives
Re: IGPs in use
From: Alex Bligh <amb () gxn net>
Date: Tue, 13 Oct 1998 20:09:47 +0100
Jared,
1) If you put your backbone connected interfaces (loopbacks serials, etc.. in your IGP [isis, ospf, whatever]) 2) Have a full iBGP mesh doing next-hop-self of the loopback interface 3) Redistribute statics and connected into your iBGP routing table (with route-map, or appropriate filters as necessary that vary by vendor)
No argument with the principles here but why do you need to redistribute connected interfaces into your IGP *and* into iBGP? Overkill, surely? IMHO all you need do is put appropriate connected interfaces and statics pointing out of your core into either the IGP *or* iBGP. Whether you do this via redistribution or not is probably network dependent. In case anyone hadn't realized (I'm sure Jared did), (2) ensures you carry round the iBGP next hop of the loopback addres of the exit router rather than (say) the next hop over the NAP concerned, which some idiot is bound to leak a more specific of just when you've forgotten to filter it. This also removes the nead for carrying the DMZ in your IGP (or, I suppose iBGP). Are there really networks out there that chose to run iBGP not only as an IGP (we do this in one AS), but also don't run something to hold up the loopback interface mesh too? (i.e. use Chris' auto-discovery method). Presumably they peer between interface addresses or it's not going to work as nothing will ever discover an arbitrary /32 loopback. Euch! -- Alex Bligh GX Networks (formerly Xara Networks)
Current thread:
- IGPs in use Andre' Zehl (Oct 12)
- Re: IGPs in use Timothy R. McKee (Oct 13)
- <Possible follow-ups>
- Re: IGPs in use Megatron (Oct 12)
- Re: IGPs in use Chrisy Luke (Oct 12)
- Re: IGPs in use Randy Bush (Oct 12)
- Re: IGPs in use David O'Leary (Oct 12)
- Re: IGPs in use Phillip Vandry (Oct 13)
- Re: IGPs in use Jared Mauch (Oct 13)
- Re: IGPs in use Alex Bligh (Oct 13)
- Re: IGPs in use Tony Li (Oct 13)
- Re: IGPs in use Chrisy Luke (Oct 12)
- Re: IGPs in use Ben Black (Oct 12)
- Re: IGPs in use Chrisy Luke (Oct 13)
- Re: IGPs in use Paul G. Donner (Oct 13)
- BGP as an IGP (Was Re: IGPs in use) Chrisy Luke (Oct 13)
- RE: IGPs in use Thom Youngblood (Oct 13)
- Re: IGPs in use bmanning (Oct 12)
- Re: IGPs in use Richard Irving (Oct 12)
- Re: IGPs in use Paul Ferguson (Oct 13)