Concept Guide
Marking Egress Packets with a DEI Value
On egress, you can set the DEI value according to a dierent mapping than ingress.
For ingress information, refer to Honoring the Incoming DEI Value.
To mark egress packets, use the following command.
• Set the DEI value on egress according to the color currently assigned to the packet.
INTERFACE mode
dei mark {green | yellow} {0 | 1}
Example of Viewing DEI-Marking Conguration
To display the DEI-marking conguration, use the show interface dei-mark [interface slot/port/subport ] in EXEC
Privilege mode.
DellEMC#show interface dei-mark
Default CFI/DEI Marking: 0
Interface Drop precedence CFI/DEI
--------------------------------
Te 1/1/1 Green 0
Te 1/1/1 Yellow 1
Te 2/9/1 Yellow 0
Te 2/10/1 Yellow 0
Dynamic Mode CoS for VLAN Stacking
One of the ways to ensure quality of service for customer VLAN-tagged frames is to use the 802.1p priority bits in the tag to indicate the
level of QoS desired.
When an S-Tag is added to incoming customer frames, the 802.1p bits on the S-Tag may be congured statically for each customer or
derived from the C-Tag using Dynamic Mode CoS. Dynamic Mode CoS maps the C-Tag 802.1p value to a S-Tag 802.1p value.
Figure 117. Statically and Dynamically Assigned dot1p for VLAN Stacking
When conguring Dynamic Mode CoS, you have two options:
• Mark the S-Tag dot1p and queue the frame according to the original C-Tag dot1p. In this case, you must have other dot1p QoS
congurations; this option is classic dot1p marking.
• Mark the S-Tag dot1p and queue the frame according to the S-Tag dot1p. For example, if frames with C-Tag dot1p values 0, 6, and 7 are
mapped to an S-Tag dot1p value 0, all such frames are sent to the queue associated with the S-Tag 802.1p value 0. This option requires
two dierent CAM entries, each in a dierent Layer 2 ACL FP block.
Service Provider Bridging
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