Question

CoS error using Priority 6. Not sure if we need to change our setup or how to avoid this

  • 27 June 2019
  • 3 replies
  • 231 views

Userlevel 2
We are in the process of deploying ExtremeControl and have run into an issue with CoS 6. If we are understanding this correctly, CoS will replace currently configured diffserv replacement values?

In our environment, we are currently using diffserv replacement to set QP6 to EF with a value of 46. We have a mix of stacked switches and some that are unstacked. For the stacked switches, we are receiving the error below when trying to push policy. We are trying to figure out if there is any way to use CoS and maintain the tagging settings that we have or if we need to change our setup. Our full QOS mappings are below:

QP8 - Network Control (CS7 Value of 56)
QP7 - Internetwork Control (CS6 Value of 48)
QP6 - VoIP (EF Value of 46)
QP5 - PCoIP (AF41 Value of 34)
QP4 - Exchange, AD, LDAP, Kereberos (AF31 Value of 26)
QP3 - TBD (AF21 value of 16)
QP2 - Windows File Sharing (AF11 Value of 10)
QP1 - Everything else No tags


code:
Device: 

Severity: Warning

Message: Enforce Warning: Stacked EXOS devices detected. In a stacked configuration Priority 6 is reserved for interswitch communication. Traffic which map to static CoS 'RTP/Voice/Video' (which uses priority 6) will actually use 801.1p priority & Transmit Queue 5 on the following device(s): 172.21.31.2


code:
Device: 172.21.31.2

Severity: Error

Message: The following COS objects need to be modified on 172.21.31.2 - RTP/Voice/Video [802.1p: 6]

3 replies

Userlevel 2
(Am I missing the button allowing me to edit my original post?)

I wanted to give more clarification regarding what we had setup via DSCP replacement:
code:
show diffserv replacement
QOSProfile->CodePoint mapping:
QP1 -> 00
QP2 *> 10
QP3 -> 16
QP4 *> 26
QP5 *> 34
QP6 *> 46
QP7 *> 56
QP8 *> 48


That is what we are trying to recreate via CoS. Is "Transmit Queue - Q0" the same as QP1, "Transmit Queue - Q1" the same as QP2, etc?
Userlevel 1
Hello Stephen,

I think it is just a simple case of difference in numbering. The IP TOS and Diffserv have priorities of 0 to 7 since that maps onto 3 bits. I'm not that familiar with Extreme Control, so I am unsure whether the QPs are built in or if they are something you have set up. Regardless, in your case QP1 would be equivalent to CS0 and in turn transmit queue 0 - which is what you seem to have concluded anyway.

Steve
Userlevel 2
Is there any way within a domain to prevent that setting from being applied to stacked switches, or do we always just have to ignore the error that gets sent out whenever we push a policy (or we just disable the warning I guess):



--
Subject: NetSight Warning Alarm: Extreme - Warning Error Critical Alert and Emergency events

Device:
Severity: Warning
Message: Enforce Warning: Stacked EXOS devices detected. In a stacked configuration Priority 6 is reserved for interswitch communication. Traffic which map to static CoS 'RTP/Voice/Video' (which uses priority 6) will actually use 801.1p priority & Transmit Queue 5 on the following device(s): [172.21.31.2].

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