White Papers

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The following combination of marking actions to be specied match sequence of the class-map command:
set a new DSCP for the packet
set the packet color as ‘yellow
set the packet color as ‘yellow’ and set a new DSCP for the packet
This marking action to set the color of the packet is allowed only on the ‘match-any’ logical operator of the class-map.
This marking-action can be congured for all of the below L3 match sequence types:
match ip access-group
match ip dscp
match ip precedence
match ip vlan
Guidelines for Conguring ECN for Classifying and
Color-Marking Packets
Keep the following points in mind while conguring the marking and mapping of incoming packets using ECN elds in IPv4 headers:
Currently Dell EMC Networking OS supports matching only the following TCP ags:
ACK
FIN
SYN
PSH
RST
URG
In the existing software, ECE/CWR TCP ag qualiers are not supported.
Because this functionality forcibly marks all the packets matching the specic match criteria as ‘yellow’, Dell EMC Networking OS does
not support Policer based coloring and this feature concurrently.
If single rate two color policer is congured along with this feature, then by default all packets less than PIR would be considered as
“Green” But ‘Green’ packets matching the specic match criteria for which ‘color-marking’ is congured will be over-written and
marked as “Yellow.
If two rate three color policer is congured along with this feature then,
x < CIR – will be marked as “Green
CIR < x< PIR – will be marked as “Yellow
PIR < x – will be marked as “Red”
But ‘Green’ packets matching the specic match criteria for which ‘color-marking’ is congured will be over-written and marked as “Yellow”.
Sample conguration to mark non-ecn packets as
“yellow” with Multiple trac class
Consider the example where there are no dierent trac classes that is all the packets are egressing on the default ‘queue0’.
Dell EMC Networking OS can be congured as below to mark the non-ecn packets as yellow packets.
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ip access-list standard ecn_0
Quality of Service (QoS)
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