QoS: Configuring the Modular Quality of Service CLI

[haji_akhundov]

Hello everyone!

I need some help regarding the configuration of QoS.

I have a switch(SLM224G) that is connected to a router (2811) (fast Ethernet sub interface, encap dot1Q3). Everything works just fine. MY end goal right now is to make certain physical ports on the switch to have a higher priority.

My proposed solution was to mark the packets on the switch with a CoS value and then use that information to classify the traffic.

For example,

I changed the switch's configuration to change mark interface e1 with CoS 3,

then the router with the following:

!

class-map match-all HI

match cos  3

!

!

policy-map MyPolicy

class HI

  priority percent 90

class class-default

  fair-queue

!

When I apply this to an interface:

interface fastethernet 0/0.2

service-policy output MyPolicy

I get: 'match cos' is not supported in an output policy

What's wrong here? How can I do this?

Thank you.

[Giuseppe Larosa]

Hello Haji,

change configurations so that  the switch marking is done assigning an OSI layer3 parameter like a DSCP value (this is mapped to the TOS-Diffserv byte in IPv4 header)

Then you change router configuration accordingly with the class defined matching on ip dscp instead of CoS

Hope to help

Giuseppe

[haji_akhundov]

Giuseppe,

Thank you for your reply.

It seems that I cannot make DSCP marking on my switch unfortunatly.

I tried an alternative way just now:

1. Mark CoS on a switch

2. match CoS on a router and SET dscp af11 (then apply as service-policy INPUT on a subinterface)

3. match DSCP af11 on a router set priority bandwidth et cetra (apply as OUTPUT)

class-map match-all dscpAF11

match  dscp af11

class-map match-all HI-PRI

match cos  5

!

!

policy-map marker

class HI-PRI

  set dscp af11

policy-map myQoS

class dscpAF11

  priority percent 90

class class-default

  fair-queue

!

interface FastEthernet0/0.3

encapsulation dot1Q 3

ip address 192.168.1.1 255.255.255.0

service-policy input marker

!

But now when I try to:

Router1(config)#int fastEthernet 0/0.3

Router1(config-subif)#service-policy output myQoS

I get:

CBWFQ : Not supported on subinterfaces

What I am doing at the moment seems logical to me..  But is there a special way of configuring logical interfaces?

[rogeriomonteiro]

haji_akhundov,

What is up man?

I see your message, i can help you.

"CBWFQ : Not supported on subinterfaces

What I am doing at the moment seems logical to me..  But is there a special way of configuring logical interfaces?"

you just have to configure a parente level at your policy, seems like this:

!

policy-map myQoS-child

class dscpAF11

  priority percent 90

class class-default

  fair-queue

!

policy-map myQoS-parent

class class-default

  shape average percent 100%

servisse-policy myQoS-child

!

interface FastEthernet0/0.3

encapsulation dot1Q 3

ip address 192.168.1.1 255.255.255.0

service-policy output myQoS-parent

!

when you tested, please replay to me.