ExtremeSwitching (EXOS)

  • 1.  OSPF - QoS/CoS Marking

    Posted 01-27-2015 14:42
    Hi All.
    I'm just wiresharking some OSPF traffic to check QoS markings and I notice that OSPF hellos generated by our Summit X460 are marked as DSCP CS6 but tagged as 802.1p priority 7.
    We've got no QoS re-marking configured on the switch.
    Can anyone explain the discrepancy and why the device doesn't use 1 to 1 class marking?
    Many thanks....


  • 2.  RE: OSPF - QoS/CoS Marking

    Posted 01-28-2015 02:35
    Hello Stephen

    If you do a show


  • 3.  RE: OSPF - QoS/CoS Marking

    Posted 01-28-2015 08:25
    thanks for your reply Paul.

    extract from a 'show vlan


  • 4.  RE: OSPF - QoS/CoS Marking

    Posted 01-28-2015 09:26
    DSCP CS6 is a layer 3 marking
    802.1p priority 7. is a Layer 2 Marking
    as they are different methods there is no defacto requirement for them to match.
    Simon Bingham ( alternative networks )




  • 5.  RE: OSPF - QoS/CoS Marking

    Posted 01-28-2015 09:36
    Yes of course, thanks Simon. I understand that but, in the absence of a QoS policy, I thought it was standard practice to mark CoS the same as the DSCP CS.


  • 6.  RE: OSPF - QoS/CoS Marking

    Posted 01-28-2015 09:53
    802.1p 7 is called Network Control so that would make sense and CS6 is the same value used by Cisco for protocol traffic so that might be why the values don't match. But as said I don't think they have to.