I would like to know if anybody can tell me how or even if fast-switching and CEF handle special packet handling decisions like extended access-lists, policy-routing, QoS (like queuing, CAR, WRED). From reading the CiscoPress book "Inside Cisco IOS Software Architecture", I understand how fast-switching and CEF work in normal packet forwarding situations. But what happens when more intelligence is needed in packet forwarding, like in situations mentioned above? I am well aware of the command "ip route-cache policy", which seems to imply that a policy route can be cached for fast-switching. I am interested in finding out how this really works. Because I can make a policy route that matches on so many different things (source IP, IP precedence/TOS value, packet length,etc.) and can change so many different things (next hop, default next hop, prec/TOS, etc.), it seems to me that the tree or trie or whatever logic structure IOS may use would quickly become overwhelmed by the sheer number of possibilities. Which makes me wonder whether the router can really cache the policy at all, or if it can, should it (as opposed to just process-switching the packet). Thanx Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=5180&t=5180 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
