Reference Guide

552 | Quality of Service
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Honoring dot1p values on ingress packets
FTOS provides the ability to honor dot1p values on ingress packets with the Trust dot1p feature. Enable
Trust dot1p using the command
trust dot1p from POLICY-MAP-IN mode. Table 30-6 specifies the queue
to which the classified traffic is sent based on the dot1p value.
The dot1p value is also honored for frames on the default VLAN; see Priority-tagged Frames on the
Default VLAN.
Fall Back to trust diffserve or dot1p
Fall Back to trust diffserve or dot1p is available only on platforms: e
When using QoS service policies with multiple class maps, you can configure FTOS to use the incoming
DSCP or dot1p marking as a secondary option for packet queuing in the event that no match occurs in the
class maps.
When class-maps are used, traffic is matched against each class-map sequentially from first to last. The
sequence is based on the priority of the rules, as follows:
1. rules with lowest priority, or in the absence of a priority configuration,
2. rules of the next numerically higher queue
011XXX AF3 Flash 3 1 1
16–31
010XXX AF2 Immediate 2 1 1
001XXX AF1 Priority 1 0 0
0–15
000XXX BE (Best Effort) Best Effort 0 0 0
Table 30-6. Default dot1p to Queue Mapping
dot1p
E-Series
Queue ID
C-Series
Queue ID
S-Series
Queue ID
0211
1000
2100
3311
4422
5522
6633
7733
DSCP/CP
hex range
(XXX)xxx DSCP Definition
Traditional IP
Precedence
E-Series
Internal
Queue ID
C-Series
Internal
Queue ID
S-Series
Internal
Queue ID
DSCP/CP
decimal