qos on an cat 3550emi

[rabeder]

hi,

we want that our 3550 switch/router marks frames with certain ip-prec values.

so we configured the following:

mls qos

!

class-map match-any mark_voip

match any

!

!

policy-map mark_traffic

class mark_voip

set ip precedence 5

class class-default

set ip precedence 1

!

!

interface GigabitEthernet0/1

description RLB-Telefon1: to RLBC1 (Trunk)

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,194,304,344,1002-1005

switchport mode trunk

service-policy input mark_traffic

!

RLB-Telefon1#sh policy-map int gigabitEthernet 0/1

GigabitEthernet0/1

service-policy input: mark_traffic

class-map: mark_voip (match-any)

0 packets, 0 bytes

5 minute offered rate 0 bps, drop rate 0 bps

match: any

0 packets, 0 bytes

5 minute rate 0 bps

class-map: class-default (match-any)

0 packets, 0 bytes

5 minute offered rate 0 bps, drop rate 0 bps

match: any

0 packets, 0 bytes

5 minute rate 0 bps

RLB-Telefon1#

as you can see no packets are running into the classes.

any idea ?

[stevek1]

G'Day,

We have noticed similar situation here. I set a rate-limiting policing action against some classified traffic entering a fastEthernet interface of a 3550-48 and noted the desired affect was being achieved via large pings timing out. But the queue info provided by the output of the show policy-map interface command continually read zeros.

May be a bug.

The only way to prove you are classifying and marking these packets may be to run a sniff on some egress traffic and look at the decoded IP headers.

In any case it looks like you will be marking everything at precedence 5 from the sample config.

Cheers, SteveK.

[rabeder]

hi,

we did some testing with sniffer.

it seems the router marks the pakets but the "sh policy..." command does not really work - it does not show anything.

we saw thet this switch /router is not really the best solution for qos features (no nbar,..)