802.1ad DEI
You can classify traffic based on the Drop Eligible Indicator (DEI) bit that is present in 802.1ad frames and in 802.1ah frames. DEI support includes the ability to:
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Police to a certain rate and, based on whether the traffic is conforming or exceeding, mark the DEI as 0 or 1.
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On ingress, police and set up the discard class (even on an interface that is not configured for 802.1ad encapsulation).
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On egress, mark the DEI based on the discard class value (802.1ad interfaces only).
You can manage congestion based on the Drop Eligible Indicator (DEI) bit that is present in 802.1ad frames and 802.1ah frames. DEI support includes the ability to:
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Do weighted random early detection (WRED) based on the value of the DEI bit.
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Do active queue management during traffic congestion on an interface by giving preferential treatment to traffic (bigger thresholds) or set up smaller thresholds for out-of-profile traffic based on a DEI value.
Mark DEI Based on a Policing Action: Example
In this example, the police rate is set to 5 Mbps. Conforming traffic is marked with a DEI value of 0; traffic that exceeds the police rate is marked with a DEI value of 1.
policy-map 1ad-mark-dei
class c1
police rate 5 mbps
conform-action set dei 0
exceed-action set dei 1
end-policy-map
Mark DEI Based on Incoming Fields: Example
In this example, 802.1ad CoS plus DEI is derived from the incoming 802.1q CoS. Packets with a CoS value of 0 are remarked with a DEI value of 1.
class-map match-any remark-cos
match cos 0
end-class-map
policy-map p1
class remark-cos
set dei 1
end-policy-map
interface GigabitEthernet0/4/0/39.1 l2transport
encapsulation dot1q 1
rewrite ingress tag push dot1ad 5 symmetric
service-policy input p1
!
Congestion Management Using DEI: Example
In this example, congestion is managed by dropping packets with a DEI value of 1 before dropping packets with a DEI value of 0.
policy-map dei-sample
class class-default
random-detect dei 1 1000 6000
random-detect dei 0 5000 10000
end-policy-map
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