When a packet arrives at the switch on an ingress port and Diffserv examination is enabled, the switch uses the DSCP value to select the egress QoS profile that forwards the packet. The QoS profile configuration defines the forwarding characteristics for all traffic assigned to the QoS profile.
Note
When DiffServ examination is enabled on 1 Gigabit Ethernet ports for BlackDiamond 8800 series switches, SummitStack, and Summit family switches, 802.1p replacement is enabled and cannot be disabled. The ingress 802.1p value is replaced with the 802.1p value assigned to the egress QoS profile.Note
When DiffServ examination is enabled on a Summit X670, or X770, the following warning message does not apply:"Warning: Enabling diffserv examination will cause dot1p replacement of 802.1q tagged packets."