nanog mailing list archives
Re: OSPF multi-level hierarchy: Necessary at all?
From: Jessica Yu <jyy () ans net>
Date: Fri, 28 May 1999 14:51:40 -0400
Btw. Flat network... Routers now have - 128 or 256 MB RAM, 300 - 400 Mhz CPU. I guess you can built flat betwork with 5,000 routers withouth hard problems.
With a network this large, probability of any router interface going down, link flapping or rotuer failure is high so it can happen frequently. With one giant flat IGP area, any such incident occuring anywhere in the network will cause network wide LSA flooding, SPF calculation and link database update. Lots of network resources including router CPU will be consumed. Even one has a lot of cpu power in super routers, it's still a good idea to prevent an outage anywhere in the network from causing network wide event i.e. to localize the problem. A giant flat IGP area in a large network does not help achieving fault isolation. --Jessica
Current thread:
- Re: OSPF multi-level hierarchy: Necessary at all?, (continued)
- Re: OSPF multi-level hierarchy: Necessary at all? Alex P. Rudnev (May 27)
- RE: OSPF multi-level hierarchy: Necessary at all? Jessica Yu (May 27)
- Re: OSPF multi-level hierarchy: Necessary at all? Vadim Antonov (May 27)
- Re: OSPF multi-level hierarch: side question Steve Meuse (May 28)
- Re: OSPF multi-level hierarch: side question Alex P. Rudnev (May 28)
- Re: OSPF multi-level hierarch: side question Steve Meuse (May 28)
- Re: OSPF multi-level hierarchy: Necessary at all? Vadim Antonov (May 27)
- Re: OSPF multi-level hierarchy: Necessary at all? Sean Donelan (May 28)
- Re: OSPF multi-level hierarchy: Necessary at all? Alex P. Rudnev (May 28)
- Re: OSPF multi-level hierarchy: Necessary at all? Alex Zinin (May 28)
- Re: OSPF multi-level hierarchy: Necessary at all? Alex P. Rudnev (May 28)
- Re: OSPF multi-level hierarchy: Necessary at all? Jessica Yu (May 28)
- Re: OSPF multi-level hierarchy: Necessary at all? Alex P. Rudnev (May 28)
- Re: OSPF multi-level hierarchy: Necessary at all? Jessica Yu (May 28)
- Re: OSPF multi-level hierarchy: Necessary at all? Alex P. Rudnev (May 31)
- Re: OSPF multi-level hierarchy: Necessary at all? Alex P. Rudnev (May 28)