From: Martin Dean (nobody@studygroup.com)
Date: Sun Sep 22 2002 - 19:29:05 GMT-3
The answer is 'depends'.
If the switch is a 5000 with MLS ACLs etc then the switch will 'route' the
traffic, once the router has routed it - Route once Switch many. This occurs
with either an RSM or a router on a stick.
If the switch is a 6000 with an MSFC, then CEF takes over and then switches
the packet with help from the PFC.
If the switch is a 1900 or 2900 then the router does all the work.
Not sure with a 3550 SMI or an EMI image. Would guess with an EMI image,
CEF does the 'routing' after the router has filled the cache with the
appropriate details.
Martin Dean
----- Original Message -----
From: "CCIE Prep" <cciemail@intellinet.ws>
To: <ccielab@groupstudy.com>
Sent: Sunday, September 22, 2002 11:00 PM
Subject: 802.1Q Trunk Question
> For the purposes of this discussion, let's assume that we have a router
> running dot1q encapsulation on an interface connected to a switch. The
> switch port is programmed as a Dot1q trunk and connectivity is established
> and functioning correctly. The router has subinterfaces programmed for
> VLAN1 and VLAN2. If a node from VLAN1 needs to communicate with a node on
> VLAN2, does all the traffic traverse the ethernet interface of the router?
> Or is the router simply used for routing decisions and the traffic remain
on
> the backplane of the switch?
>
> Thanks in advance.
>
> __________
>
> Nate Kleven
>
> Senior Network Engineer, CCNP Voice Access, MCSE
>
> Expanets
>
> 6020 So 190th ST
>
> Kent, WA 98032
>
> (206)219.6135
>
> "Experienced at Networked Solutions"
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