Reference Guide

812 | Service Provider Bridging
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sent to the queue associated with the S-Tag 802.1p value 0. This option requires two different
CAM entries, each in a different Layer 2 ACL FP block.
Note: The ability to map incoming C-Tag dot1p to any S-Tag dot1p requires up to 8 entries to be installed
in the Layer 2 QoS and Layer 2 ACL table for each configured customer VLAN. The scalability of this
feature is limited by the impact of the 1:8 expansion in these CAM tables.
Dell Networking OS Behavior: For Option A above, when there is a conflict between the queue selected by
Dynamic Mode CoS (vlan-stack dot1p-mapping) and a QoS configuration, the queue selected by Dynamic Mode
CoS takes precedence. However, rate policing for the queue is determined by QoS configuration. For example, the
following access-port configuration maps all traffic to Queue 0:
vlan-stack dot1p-mapping c-tag-dot1p 0-7 sp-tag-dot1p 1
However, if the following QoS configuration also exists on the interface, traffic is queued to Queue 0 but will be rate policed
at 40Mbps (qos-policy-input for queue 3) since class-map "a" of Queue 3 also matches the traffic. This behavior is expected.
policy-map-input in layer2
service-queue 3 class-map a qos-policy 3
!
class-map match-any a layer2
match mac access-group a
!
mac access-list standard a
seq 5 permit any
!
qos-policy-input 3 layer2
rate-police 40
Likewise, in the configuration below, packets with dot1p priority 0 – 3 are marked as dot1p 7 in the outer
tag and queued to Queue 3. Rate policing is according to
qos-policy-input 3. All other packets will have
outer dot1p 0 and hence are queued to Queue 1. They are therefore policed according to
qos-policy-input 1.
A policy map output with rate shape for different queues can also be used.
policy-map-input in layer2
service-queue 1 qos-policy 1
service-queue 3 qos-policy 3
!
qos-policy-input 1 layer2
rate-police 10
!
qos-policy-input 3 layer2
rate-police 30
!
interface TenGigabitEthernet 0/21
no ip address
switchport
vlan-stack access
vlan-stack dot1p-mapping c-tag-dot1p 0-3 sp-tag-dot1p 7
service-policy input in layer2
no shutdown