Customer requested to Remark the packets for a specific destination network and keep trust DSCP for the other packets.
Tested in the lab following configuration:
I used an Traffic Policy to remark, with an ACL to match traffic for a specific source or destination and apply the traffic policy on the outbound direction of the interface.
The test confirmed that when i used an IP as a source that match the ACL the packets will be Remark as DSCP EF (Expedited Forwarding) and when i use a different IP that doesn't match the ACL the packets will be only DSCP Default.
[Switch] acl 3000
[Switch-acl-adv-3000] rule permit ip source x.x.11.2 0
[Switch] traffic classifier c1 operator and
[Switch-classifier-c1] if-match acl 3000
[HUAWEI] traffic behavior b1
[HUAWEI-behavior-b1] remark dscp ef
[Switch] traffic policy p1
[Switch-trafficpolicy-p1] classifier c1 behavior b1
[Switch] interface gigabitethernet 0/0/10
[Switch-GigabitEthernet0/0/10] traffic-policy p1 outbound
Remark done when ACL match the source
DSCP Defalt keeped when ACL doesn't match the packets: