At 15:33 27.05.99 -0700, Vadim Antonov wrote:

Tony Li <tony1@home.net> wrote:

...

I suspect that the main driver is not the amount of routing information in the gross sense, but the scalability of the protocol as the number of nodes increases.

There's a better solution: decrease the number of nodes by replacing clusters with bigger boxes. This has an additional advantage of reducing number of hops (and, consequently, latency variance).

"Have more bigger boxes rather than less smaller ones"-approach is not for everybody and not for every case. If you have clusters sitting in one room, powered from the same source, sharing the same ceiling that can fall, running the same version of soft, using the same config., etc., than yes it's ok, because they will more likely crash at the same moment. Otherwise, I'd think first. Also, even if you do use a large box, you probably don't wanna know all the details about it's connections at some level of your network.

PS. Using DUAL or DASM instead of SPF helps, too -- these algorithms tend to eliminate updates which "do not matter" unlike SPF-based algorithms which have to inform everyone about local topology changes.

In SPF-based protocols we have areas for this purpose---we do not propogate topology information across the area boundaries. Also, magically we don't have SIAs in SPF even when there's a lot of traffic :) ------------------------------------------------------------------ Alex D. Zinin, Consultant CCSI #98966 CCIE #4015 AMT Group / ISL Cisco Systems Gold Certified Partner http://www.amt.ru irc: //EFNET/#cisco, //irc.msn.com/#NetCisco [Ustas]