Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Catalyst 4948 QoS configuration (IOS 122-46.SG)

I have some Catalyst 4948-10GE switches configured for QoS with COS to DSCP mapping commands. On each interface "qos cos 1" and "qos trust cos" are configured. A WireShark monitor of any port reveals that the packet DSCP value is "0x00". Have tried trust dscp with dscp default of 10 and configuring a Service Policy to tag "any" traffic with a DSCP value of "af", but the packets still have a DSCP value of "0x00".

Any solutions available?

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Silver

Re: Catalyst 4948 QoS configuration (IOS 122-46.SG)

Hello Rob,

basic check:

1)

have you configured mls qos in global config mode ?

conf t

qos

see

http://cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/46sg/configuration/guide/qos.html#wp1207227

2) cos settings apply to L2 trunk ports where an 802.1p CoS field is present in the 802.1Q header if the ports are access ports this setting is not effective for them.

3) are you using an monitor session or capturing traffic directed to the PC ?

Hope to help

Giuseppe

2 REPLIES
Hall of Fame Super Silver

Re: Catalyst 4948 QoS configuration (IOS 122-46.SG)

Hello Rob,

basic check:

1)

have you configured mls qos in global config mode ?

conf t

qos

see

http://cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/46sg/configuration/guide/qos.html#wp1207227

2) cos settings apply to L2 trunk ports where an 802.1p CoS field is present in the 802.1Q header if the ports are access ports this setting is not effective for them.

3) are you using an monitor session or capturing traffic directed to the PC ?

Hope to help

Giuseppe

New Member

Re: Catalyst 4948 QoS configuration (IOS 122-46.SG)

Giuseppe,

Was using a monitor session to check the QoS value. Have found out that the QoS settings cannot be seen via a monitor port. Need to analyze the data from another device on the same switch, or monitor a trunk link.

RobJ

3714
Views
0
Helpful
2
Replies