Re: OSPF multi-level hierarchy: Necessary at all?

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). K.I.S.S. rulez :) --vadim 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.