Enabling Drop Eligibility; Honoring The Incoming Dei Value - Dell C9000 Series Networking Configuration Manual

Enabling Drop Eligibility

Enable drop eligibility globally before you can honor or mark the DEI value.
When you enable drop eligibility, DEI mapping or marking takes place according to the defaults. In this case,
the CFI is affected according to the following table.
Table 81. Drop Eligibility Behavior
Ingress
Normal Port
Trunk Port
Access Port
To enable drop eligibility globally, use the following command.
• Make packets eligible for dropping based on their DEI value.
CONFIGURATION mode
dei enable
By default, packets are colored green, and DEI is marked 0 on egress.

Honoring the Incoming DEI Value

To honor the incoming DEI value, you must explicitly map the DEI bit to a drop precedence value.
Precedence can have one of three colors.
Precedence Description
Green High-priority packets that are the least preferred to be dropped.
Yellow Lower-priority packets that are treated as best-effort.
Red Lowest-priority packets that are always dropped (regardless of congestion status).
• Honor the incoming DEI value by mapping it to a drop precedence value.
INTERFACE mode
dei honor {0 | 1} {green | red | yellow}
You may enter the command once for 0 and once for 1.
Packets with an unmapped DEI value are colored green.
Example of Viewing DEI-Honoring Configuration
To display the DEI-honoring configuration, use the show interface dei-honor [interface slot/
port | linecard number port-set number] in EXEC Privilege mode.
Egress
Normal Port
Trunk Port
Trunk Port
DEI Disabled
Retain CFI
Retain inner tag CFI
Retain outer tag CFI
Retain inner tag CFI
Set outer tag CFI to 0
Service Provider Bridging
DEI Enabled
Set CFI to 0.
Retain inner tag CFI.
Set outer tag CFI to 0.
Retain inner tag CFI
Set outer tag CFI to 0
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