[c-nsp] WCCPv2 - what happens to existing connections when redirect-list is modified?

Dale Shaw dale.shaw+cisco-nsp at gmail.com
Thu May 21 23:38:23 EDT 2009

Hi all,

Scenario: WCCPv2 configured and active for WAAS, all TCP traffic
redirected (no redirect-list configured for service groups 61 and 62)

What happens to active/existing TCP sessions that _are_ being
intercepted/redirected if I configure a redirect-list with a 'deny'
statement that matches the session?

I'm not intimately familiar with WCCPv2 operation but I assume these
are the possibilities:

1) existing connections are not affected and continue to be
intercepted/redirected in spite of ACL; new connections are not
intercepted/redirected; WCCP is smart!
2) new packets for existing connections stop being
intercepted/redirected and are routed normally - TCP copes OK and
sessions stay up; TCP is amazing!
3) as above, but TCP does not cope, as SEQs/ACKs etc. change; sessions
are torn down/time out; TCP is only human
4) something else :-)

Can anyone provide any insight?

Adrian Chadd, I'm shining the bat torch towards the sky, are you out there? :-)


More information about the cisco-nsp mailing list