On Wed, Sep 02, 2009 at 02:42:31PM +0200, Peter Rathlev wrote: > Agreed, and introducing DFCs can give you some headaches with e.g. > policers, since each forwarding engine operates independently from the > others.
I guess here you're referring to the fact that there is no communication of ingress rates between individual DFCs, or back to the PFC? I posed this question to Cisco at a CPOC lab, and have also heard the same from TAC. Consider the following scenario: Two flows are ingress on a 6500, one on Gi1/0 (where slot 1 has a DFC), and one on Gi2/0 (where slot 2 also has a DFC). They are egress on a third port Gi3/0, which also has a DFC. Since the policing is performed by the ingress LC, if Gi3/0 has a 50Mbps policer, and the flows at Gi1/0 and Gi2/0 are both 40Mbps, neither card will drop any packets, and hence the egress rate at port Gi3/0 is 80Mbps, despite having a 50Mbps policer configured. Unfortunately, I don't have the resources to test this - has anyone tried this scenario, and verified this is _actually_ how things work, rather than theoretically? (I think the official answer for this was..."This will be fixed in EARL 8") Thanks, Rob -- Rob Shakir <[email protected]> Network Development Engineer GX Networks/Vialtus Solutions ddi: +44208 587 6077 mob: +44797 155 4098 pgp: 0xc07e6deb nic-hdl: RJS-RIPE This email is subject to: http//www.vialtus.com/disclaimer.html _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
