RE: DSCP/COS

From: Eric.Stuhl@ferguson.com
Date: Tue May 09 2006 - 09:22:53 ART


On my 6509s, I tend to use mls qos trust cos pass-through DSCP. Gives
you the best of both worlds as the cos value is trusted and the DSCP is
unchanged. Then again, I do several instances where my port channels are
both layer 2 and 3. At pure layer three, I'd imagine that just trusting
DSCP would be fine.

Eric Stuhl
CCNP, CCDP, CCSE-NG
Ferguson Enterprises
eric.stuhl@ferguson.com
(757)-969-4146

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
devecchio
Sent: Monday, May 08, 2006 9:19 PM
To: 'Bob Sinclair'; ccielab@groupstudy.com
Subject: RE: DSCP/COS

6500 real life problem, I am going to go with dscp since the
port-channel has an ip.

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Bob Sinclair
Sent: Monday, May 08, 2006 4:30 PM
To: devecchio; ccielab@groupstudy.com
Subject: Re: DSCP/COS

devecchio,

Seems to me you could trust either, but DSCP makes more sense. Is this
a lab problem or real life? 3550 or 6500? On 3550 all qos is physical
port level, and ports in an L3 Po are still L2, and COULD be
trunked/tagged.

Can you give more context?

Bob Sinclair
CCIE #10427, CCSI 30427
www.netmasterclass.net

  ----- Original Message -----
  From: devecchio
  To: 'devecchio' ; ccielab@groupstudy.com
  Sent: Monday, May 08, 2006 4:05 PM
  Subject: RE: DSCP/COS

  Any takers?

  -----Original Message-----
  From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
  devecchio
  Sent: Monday, May 08, 2006 12:40 PM
  To: ccielab@groupstudy.com
  Subject: DSCP/COS

  Guys,

  I am configuring a L3 port-channel to a distro and all members of this
  portchannel are just standard gig interface with the portchannel
command.
ON
  a L3 portchannel, I have the ip configured etc. the command mls qos
trust
  dscp is to be used instead of cos due to it being a l3 port? Although
the
  switch will map cos-dscp vice versa it will not be expecting a cos
value on
  a l3 port? The rule states if connecting to a router trust dscp/if a
switch
  trust cos...I am guessing the rule still applies for switches as l2
port
  channels and roulers as l3 port channels..

 



This archive was generated by hypermail 2.1.4 : Thu Jun 01 2006 - 06:33:21 ART