Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

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ozgur_guler_344's avatar
ozgur_guler_344
Icon for Nimbostratus rankNimbostratus
Feb 01, 2010

dscp marking

Hello;

 

 

I want to mark dscp bit of the traffic originating from virtual server? How can i do that? Wtih an irule or on GUI?

2 Replies

  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Feb 01, 2010
    Hi Ozgur,

     

     

    I don't believe there is a way to set this flag on a packet. You could contact F5 Support to confirm this and/or request an enhancement.

     

     

    Aaron
  • Fred_Wittenberg's avatar
    Fred_Wittenberg
    Historic F5 Account
    Nov 17, 2016

    Realize this is quite dated but I just had to do this for a customer. To set the value to say CS2 you would perform the following:

     

    iptables -t mangle -A OUTPUT -j DSCP --set-dscp-class CS2

     

    NOTE: This change will not persist through reboots. you will need to run iptables-save or use a iptables config such as this

     

    *mangle :PREROUTING ACCEPT [0:0] :OUTPUT ACCEPT [0:0]

     

    Add CS2 Marker

    -A OUTPUT -j DSCP --set-dscp-class CS2 COMMIT *nat :PREROUTING ACCEPT [0:0] :POSTROUTING ACCEPT [0:0] :OUTPUT ACCEPT [0:0] COMMIT