[c-nsp] IRB and 802.1q subinterfaces - How to set COS?

[Robert Johnson]

IOS 12.4 advanced enterprise on a 3745. I have two fast ethernet
interfaces, each with a set of 802.1q subinterfaces. Each subinterface
has a bridge-group assigned to it so that select VLANS on each FE port
are bridged. I'd like to apply a policy-map to one of the outbound
subinterfaces that looks at the DSCP value of outbound IP packets and
sets an 802.1p COS according to the DSCP value found. Here's the
relevant part of the configuration:


class-map match-all assure
 match ip dscp af31
class-map match-all critical
 match ip dscp cs6
class-map match-all expedite
 match ip dscp ef
!
policy-map output-cos
 class expedite
  set cos 6
 class assure
  set cos 5
 class critical
  set cos 7
!
interface FastEthernet1/0
 description Trunk to switch 1
 no ip address
 full-duplex
!
interface FastEthernet1/0.500
 encapsulation dot1Q 500
 bridge-group 100
 service-policy output output-cos
!
interface FastEthernet2/0
 description trunk to cheverly-md-s1b
 no ip address
 full-duplex
!
interface FastEthernet2/0.500
 description Customer access
 encapsulation dot1Q 500
 bridge-group 100
 service-policy output output-cos
!
interface BVI100
 ip address x.x.x.x y.y.y.y
 ip verify unicast reverse-path
!
bridge 100 protocol ieee
bridge 100 route ip


The policy-map can't be applied to the BVI since it's not handling
VLAN tagging. However, the above configuration doesn't pick up any of
the traffic marked with the DSCPs specified in the class-map:

#sho policy-map int f1/0.500
 FastEthernet1/0.500

  Service-policy output: output-cos

    Class-map: expedite (match-all)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: ip dscp ef (46)
      QoS Set
        cos 6
          Packets marked 0

    Class-map: assure (match-all)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: ip dscp af31 (26)
      QoS Set
        cos 5
          Packets marked 0

    Class-map: critical (match-all)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: ip dscp cs6 (48)
      QoS Set
        cos 7
          Packets marked 0

    Class-map: class-default (match-any)
      4380 packets, 297206 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: any

Also, the class-default class does not seem to be counting in tune
with the actual traffic flowing across the subinterface.

This configuration works if the BVI is removed and IP addresses are
assigned directly to the subinterfaces. Unfortunately this is not a
practical solution due to other design considerations.

Ideas? TIA.