nanog mailing list archives
Re: OSPF multi-level hierarchy: Necessary at all?
From: "Alex P. Rudnev" <alex () Relcom EU net>
Date: Mon, 31 May 1999 14:04:50 +0400 (MSD)
I was talking about ISP network which mostly is leased-line based. It depends on link stability and router stability. As I pointed out in my previous message, the more router and link a network has (i.e. the large scaled network), the large chance of having link flapping and router crashes (if you think in percentage sense), the more flooding, SPF calculation and LSDB update all routers in the network have to handle. If there is a hierarchy, then only a portion of routers (not all the routers) would need to handle flooding, SPF calculation and LSDB update.
You are 100% right - it's the classic. Through the initial question whas _does we need hierarchical multi-level SPF routing schema?_. And my opinion was _yes, but due to administration, but not CPU/memory issues (yes, this is important too but it's importance is usially overestimated). And no one from this list argued for this hierarchy at all.
Also, the large the size of network (lots of routers and links), the bigger the LSDB and the higher complexity of SPF calculation. --Jessica
Aleksei Roudnev, Network Operations Center, Relcom, Moscow (+7 095) 194-19-95 (Network Operations Center Hot Line),(+7 095) 230-41-41, N 13729 (pager) (+7 095) 196-72-12 (Support), (+7 095) 194-33-28 (Fax)
Current thread:
- Re: OSPF multi-level hierarch: side question, (continued)
- 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)