From: Bob Sinclair (bsin@cox.net)
Date: Sun Dec 21 2003 - 13:04:09 GMT-3
William,
If you mark packets with a DSCP inbound an interface, then you will see the
DSCP in the output packets, and you will see that the COS has been set per
the default DSCP-COS map.
I verified this as follows:
1. I applyied a service-policy inbound that set all DSCP to 35.
2. I changed the encap on the outbound port to my pc to ISL
3. I turned on my sniffer (note that my NIC is not ISL, I had to do a
static arp entry on the sending box)
4. The sniffer showed DSCP set as expected and it showed the ISL user field
set to 4, which is the default mapping.
Hope this helps, sometimes a debug or sniffer is the only way to get a
definitive answer.
-Bob Sinclair
CCIE #10427, CISSP, MCSE
www.netmasterclass.net
----- Original Message -----
From: "William Chen" <kwchen@netvigator.com>
To: <ccielab@groupstudy.com>
Sent: Sunday, December 21, 2003 2:17 AM
Subject: Catalyst 3550 QoS
> Dear all,
>
> The Catalyst 3550's Classification will result an internal DSCP. Will
> this DSCP be actually marked in the packets or just for internal use only?
> How about the COS value after DSCP-to-COS map applied, will it be internal
> use only to select the output queue or will actually marked in the tagged
> frames. I think DocCD don't clearly states it.
>
> Best Regards,
> William Chen
>
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