On Dec 29, 2011, at 2:27 AM, Vitkovsky, Adam wrote:
... host systems should participate in IGP
We tried that.
It didn't scale well.
The Internet today is very different than the Internet in 1981.
-did you? I thought CLNS with plethora of ip addresses compared to ipv4 was buried before it could be widely deployed, I was not around back than but would like to know why ES-IS did not scale well when integrated IS-IS is still used primarily for great scalability
??? CLNS carried NSAPs, not IP addresses. ES-IS was the protocol between hosts and routers, very much akin to ARP. IS-IS was the IGP used for CLNS. Yes, it's the same one that we use today for IP. Even in the ISO model, hosts did not participate in IS-IS. There was no particular scalability problem with ES-IS, other than the mcast burden that it imposed on the link layer. This is not radically different than the burden that ARP broadcasts require. Limit your broadcast domains. Tony