forwarding-class (Fibre Channel Interfaces)
Syntax
forwarding-class lossless-forwarding-class-name;
Hierarchy Level
[edit class-of-service interfaces fibre-channel-interface-name]
Description
Configure a Layer 3 fixed classifier on a Fibre
Channel (FC) interface. The fixed classifier places all traffic received
from the FC network into the specified forwarding class. The forwarding
class must be lossless. (That is, the forwarding class must be either
the default fcoe or no-loss forwarding class,
or the forwarding class must be configured with the no-loss drop attribute.) If you attempt to specify a lossy forwarding class,
the system returns a commit error.
FCoE networks typically use priority 3 (IEEE code point 011)
for FCoE traffic. The QFX Series default configuration uses IEEE 802.1p
priority 3 for FCoE traffic. If the IEEE 802.1p code point value that
the Ethernet network uses for FCoE traffic is different than code
point 3, you can rewrite the code point to the value used in your
Ethernet (FCoE) network. The lossless forwarding class specified in
the fixed classifier uses the rewrite-value statement as
the IEEE 802.1p code point (priority) for FCoE traffic on the FCoE
network.
To rewrite the code point value, include the rewrite-value
input ieee code-point code-point-bits statement
at the [edit class-of-service interfaces fc-interface-name] hierarchy level.
If you are not using the default configuration (priority 3 for FCoE traffic), the lossless forwarding class specified in the FC interface fixed classifier must be mapped to the IEEE 802.1p code point specified in the rewrite value statement.
In order to avoid fate sharing (separate flows that affect each
other’s throughput), the code point (priority) used for the
lossless forwarding class (the code point specified in the rewrite
value statement) should be the only code point classified to that
forwarding class (at the [edit class-of-service classifiers] hierarchy level). For example, if the rewrite value uses code point
101 for lossless FCoE forwarding class fcoe_fc1, then in the classifier
configuration attached to ingress Ethernet interfaces, code point
101 is the only code point that should be classified to the fcoe_fc1
forwarding class. Now if you also attach a classifier to an interface
that maps code point 110 to forwarding class fcoe_fc1, then congestion
on priority 110 unfairly (and unintentionally) affects the FCoE traffic
that uses priority 101. Both priorities 101 and 110 are classified
into forwarding class fcoe_fc1, so the traffic from both priorities
shares the same fate.
Options
lossless-forwarding-class-name—Name of the lossless forwarding class.
Required Privilege Level
interfaces—To view this statement in the configuration.interface-control—To add this statement to the configuration.
Release Information
Statement introduced in Junos OS Release 12.3.