Service Manual

By default, all packets are considered as ‘green’ (without the rate-policer and trust-diffserve
configuration) and hence support would be provided to mark the packets as ‘yellow’ alone will be
provided.
By default Dell Networking OS drops all the ‘RED’ or ‘violate’ packets.
The following combination of marking actions to be specified 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 configured for all of the below L3 match sequence types:
• match ip access-group
• match ip dscp
• match ip precedence
• match ip vlan
Guidelines for Configuring ECN for Classifying and Color-
Marking Packets
Keep the following points in mind while configuring the marking and mapping of incoming packets using
ECN fields in IPv4 headers:
• Currently Dell Networking OS supports matching only the following TCP flags:
– ACK
– FIN
– SYN
– PSH
– RST
– URG
In the existing software, ECE/CWR TCP flag qualifiers are not supported.
• Because this functionality forcibly marks all the packets matching the specific match criteria as
‘yellow’, Dell Networking OS does not support Policer based coloring and this feature concurrently.
• If single rate two color policer is configured along with this feature, then by default all packets less
than PIR would be considered as “Green” But ‘Green’ packets matching the specific match criteria for
which ‘color-marking’ is configured will be over-written and marked as “Yellow”.
• If two rate three color policer is configured along with this feature then,
– x < CIR – will be marked as “Green”
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Quality of Service (QoS)