About Ingress Port Trust

By default, there is no configuration required for trusting the traffic’s marking in ingress: the hardware uses the 802.1Q packets’ CoS field for classification.

However, when the network administrator needs to trust the IP marking in the DSCP field, then trust can be changed to DSCP-based for IP traffic by configuring a DSCP to CoS mapping, as described in the next section. In such case, the CoS values associated to the trusted DCSP values also reflect in egress in the packets’ CoS field.