From: Florian Weimer <fw@deneb.enyo.de> Date: Mon, 26 May 2003 09:18:19 +0200 Cisco IOS doesn't have this hash collisions problem, they have moved away from hash tables ages ago. Let their loss be our gain :-) No, I am serious, their solution to misbehaving flows seems to be just using slow path always and continually optimize the slow path. the data structure are changed when updated routing information is encountered and not when packets are received which need to be routed. Yes, they say this in the marketing literature too. :) Now, how about some real explanation about what they are actually doing? Are they replicating the routing table all over the place? That's one possibility, and would match up to their saying that more router memory is required when using CEF. The other possibility is that it's a faster-trie thing generated from the normal routing tables. Since CEF aparently works with QoS and other features, the key must be many bits wide. Probably similar in size to our flowi's. So some bit branching trie based upon flow parameters. There are hundreds of patented such schemes :-) Anyways, you keep saying that flow hashing is stupid, can you propose an alternative? Really, I don't mean to be rude, but you do a lot of complaining about how what we have now sucks and zero of actually suggesting a usable alternative. - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
