nanog mailing list archives
Re: largest OSPF core
From: Mark Smith <nanog () 85d5b20a518b8f6864949bd940457dc124746ddc nosense org>
Date: Fri, 3 Sep 2010 07:20:18 +0930
On Thu, 02 Sep 2010 15:20:05 +0300 lorddoskias <lorddoskias () gmail com> wrote:
I'm just curious - what is the largest OSPF core (in terms of number of routers) out there?
Presuming OSPF and IS-IS SPF costs are fairly similar, the following page from "The complete IS-IS routing protocol" (really quite a good book, a bit of a shame that there are occasional minor errors that better technical editing would have picked up) shows that relatively modern (although a number of years old now) routers can perform SPF calcs on SPF databases with 10000 routers and 25000 links in less than a second. From that, it would seem that areas / levels are obsolete for most networks for the purposes of reducing SPF calculation time. Still possibly useful for route aggregation, although if BGP is carrying nearly all your routes, that may not be that useful either. http://books.google.com.au/books?id=NxIadsCKZxMC&lpg=PP1&dq="IS-IS"&pg=PA481#v=onepage&q&f=false
Current thread:
- RE: largest OSPF core, (continued)
- RE: largest OSPF core Deepak Jain (Sep 02)
- Re: largest OSPF core Chuck Anderson (Sep 02)
- Re: largest OSPF core Warren Kumari (Sep 03)
- Re: largest OSPF core Leo Bicknell (Sep 02)
- Re: largest OSPF core Alex Ryu (Sep 02)
- Re: largest OSPF core Christian Martin (Sep 02)
- Re: largest OSPF core Randy Bush (Sep 02)
- Re: largest OSPF core Christian Martin (Sep 02)
- Re: largest OSPF core Leo Bicknell (Sep 02)