Default QOS trust parameters

[michael.e.reid]

I have a device connected to a Cat2950 which has an IP precedence of 5. With the default settings on the switch will this IP precedence stay at 5 or be untrusted and set to 0 ?

The COS override is set to disable so I suspect not ?

Cat2950#show mls qos interface

FastEthernet0/23

trust state: not trusted

trust mode: not trusted

COS override: dis

default COS: 0

pass-through: none

trust device: none

[Georg Pauwen]

Hello,

according to the ´Catalyst 2950 Series Switches Quality of Service (QoS) FAQ´:

In Cisco IOS Software Release 12.0(5)WC1 and later, the 2950 series switches honor the CoS value of an incoming frame by default.

Note: For untagged frames that are received on trusted and untrusted ports, QoS assigns the CoS value that the mls qos cos interface configuration command specifies. By default, this value is zero, which is trusted.

So, as I understand it, the precedence is maintained, unless you manually override it.

Catalyst 2950 Series Switches Quality of Service (QoS) FAQ

http://www.cisco.com/en/US/tech/tk389/tk813/technologies_q_and_a_item09186a00804976d3.shtml#qa9

HTH,

GP

[michael.e.reid]

Thanks GP,

This device is just connected via an access port, so no trunking will mean no COS in the frame.

I am really wondering about the IP precedence value in the IP headers from the server (which sets the IP Prec to 5) and if that will stay at 5 by default ?

Cheers,

Mike