[c-nsp] DCEF720 card together with CEF256/classic line cards in Cat6.5k with Sup720?

[Lars Fenneberg]

Hey Brian,

Quoting Brian Turnbow (b.turnbow at twt.it):

> > Is a DCEF720 card like the WS-X6708-10G-3CXL supported together with a
> > Supervisor 720 and a bunch of classic and CEF256 line cards?
> 
> Short answer yes, long answer is that mixing dfc cards brings limitations, all dfcsgoing to lowest common denominator, OIR etc.

thanks for your answer. I'm not so much concerned about mixing different
revisions of PFC/DFCs as the supervisor engine has a PFC3BXL so it'll fall
back to 3BXL which is okay.  I'm thinking about the packet flow in such a
scenario: Is the forwarding decision made on the DFC and the packet is
then transfered via the switching fabric to the supervisor which then puts
it on the bus? So the supervisor is just used as a gateway from the
switching fabric to the bus?

I've found several presentations on the topic [1] but they don't talk about
the DCEF/classic combination.

Cheers,
Lars

[1] http://www.scribd.com/doc/21695833/Cisco-Catalyst-6500-Switch-Architecture
-- 
Lars Fenneberg, lf at elemental.net (private), lf at mcs.de (work)
Work legalese: MCS Moorbek Computer Systeme GmbH, Hamburg, Handelsregister Hamburg B62933, Geschaeftsfuehrer: Kai Brandes, Eckard Kabel