[c-nsp] QoS & DSCP bits through a cisco router

[Oliver Boehmer (oboehmer)]

Matthew Crocker <> wrote on Wednesday, May 23, 2007 3:06 PM:

[...]
> R1 is a Cisco 12008 (GRP-B, GE-GBIC-B)
>
> How can I get R1 to preserve the DSCP bits on packets entering in
> from my private network?
> i.e.  How do I tell the GSR to trust the traffic coming from G0/0 &
> G5/0 (my internal switches) but not from G4/0 (my GigE Sprint
> connection) ?

GSR (as other routers) don't have the concept of port trust state. By
default, they pass the TOS-byte unmodified. If they don't, you might
have configured MQC (policy-maps) or CAR (rate-limit) to modify them.
Need to look at the config to tell..

	oli