Re: [squid-users] Squid and level 4 switch

On Tue, Jul 17, 2007, Ming-Ching Tiew wrote:

> I got the word "level 4 switch" from someone who knows nothing else,
> so I have to make guesses too. But I would imagine that it is doing L2
> rewrite.
> Care to elaborate how the L2 rewrite in Cisco TCAM works ?

I'm not a Cisco engineer. :) They basically match on various parts of the
IP/TCP header using TCAM rules and set the next-hop.

> Does it constantly do arp request based on IP of the cache engine and update
> the MAC address accordingly ( much like ip routing does ) or it statically
> configure the the mac address of the cache engine ?

I can't tell you without inspecting the CEF/TCAM tables on a Cisco device
running WCCPv2. I'd -guess- there's an L3 rewrite which the WCCPv2 L2
requirement of "must be directly connected" translates essentially into
an L2 rewrite. The end result -is- an L2 rewrite though, and stuff is
negotiated using the router and cache IP addresses..

Just pick up a cheap Cisco 3550 off Ebay; they do WCCPv2 with L2 redirect
good enough for experimenting.

Adrian
Received on Tue Jul 17 2007 - 01:47:38 MDT