nanog mailing list archives
Re: IGPs in use
From: Tony Li <tli () juniper net>
Date: 13 Oct 1998 15:18:00 -0700
hcb () clark net (Howard C. Berkowitz) writes:
When I gave my OSPF tutorial at NANOG in June, I stressed OSPF shouldn't be thought of purely as a 2-level hierarchy with a routing domain consisting of an area 0 and a set of nonzero areas. Some of the OSPF scaling problems I see, and these are probably equally likely in IS-IS, come from people trying to put everything into a single OSPF routing domain. Aside from performance issues, this can become a network administration nightmare. Splitting the interior network into several IGP routing domains, and linking these with a backbone-of-backbones, helps both performance and administration. The backbone group doesn't need to be concerned with LAN installations in a POP or customer site. Depending on the particular network, you might link IGP routing domains with: -- static routes -- iBGP, putting all IGPs in a single AS -- iBGP and eBGP in a confederation -- Hybrid layer 2/3 techniques, such as linking IGP-routed domains to internal layer 2 "superhubs" How much IGP support you need will depend on your network. A large enterprise, or a provider of both connectivity and content, will probably need more IGP stuff than a pure connectivity provider.
Howard, Yes, those sound like a list of administrative nightmares. ;-) Wouldn't it be much easier to make use of a three or four level hierarchical IGP? Tony
Current thread:
- Re: IGPs in use, (continued)
- 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)
- Re: IGPs in use Howard C. Berkowitz (Oct 13)
- Re: IGPs in use Tony Li (Oct 13)
- Scaling Existing IGP Administration (was) Re: IGPs in use Howard C. Berkowitz (Oct 14)
- Re: IGPs in use Henk Smit (Oct 14)
- Message not available
- Re: IGPs in use Henk Smit (Oct 14)
- Re: IGPs in use I Am Not An Isp (Oct 13)
- Re: IGPs in use Paul G. Donner (Oct 13)