[c-nsp] Cisco 7600 vlan issue

Ian Cox icox at cisco.com
Mon Dec 1 14:39:44 EST 2008

Julio Arruda wrote:

> I was under impression the L3 forwarding and the L2 forwarding was done
> by the same engine, in the PFC card(s) ? and behind it, the EARL for the
> lookup and the rewriting of the header info (mac rewrite, dec ttl and
> goes on) ?

PFC/DFC - is the customer facing name for the L2 and L3/L4 forwarding
engines on the 6500.

EARL x - is the internal name used to refer to the L2 and L3/L4
forwarding engine, x being the generation of the forwarding engine. EARL
generation and PFC/DFC versions do not directly match, but map as follows

5	PFC		Supervisor 1A
6	PFC2 / DFC	Supervisor 2
7	PFC3 / DFC3	Supervisor 720

Depending upon the features and the availability of particular ASIC
processes the forwarding engine has ranged from four ASICs to a single
ASIC. The exact number varies from generation to generation, and even
within revisions within a generation.


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