Administrator Guide

Honoring dot1p Priorities on Ingress Traffic
By default, the system does not honor dot1p priorities on ingress traffic.
You can configure this feature on physical interfaces and port-channels, but you cannot configure it on individual interfaces in a port
channel.
You can configure service-class dynamic dot1p from CONFIGURATION mode, which applies the configuration to all interfaces. A
CONFIGURATION mode service-class dynamic dot1p entry supersedes any INTERFACE entries. For more information, refer to Mapping
dot1p Values to Service Queues.
NOTE: You cannot configure service-policy input and service-class dynamic dot1p on the same interface.
• Honor dot1p priorities on ingress traffic.
INTERFACE mode
service-class dynamic dot1p
Dell#config t
Dell(conf)#interface tengigabitethernet 1/2
Dell(conf-if)#service-class dynamic dot1p
Dell(conf-if)#end
Dell#
Priority-Tagged Frames on the Default VLAN
VLAN Priority-tagged frames are 802.1Q tagged frames with (default) VLAN ID 0. For VLAN classification, these packets are treated as
untagged. However, the dot1p value is still honored when you configure service-class dynamic dot1p or trust dot1p.
When priority-tagged frames ingress an untagged port or hybrid port, the frames are classified to the default VLAN of the port and to a
queue according to their dot1p priority if you configure service-class dynamic dotp or trust dot1p. When priority-tagged
frames ingress a tagged port, the frames are dropped because, for a tagged port, the default VLAN is 0.
Dell Networking OS Behavior: Hybrid ports can receive untagged, tagged, and priority tagged frames. The rate metering calculation
might be inaccurate for untagged ports because an internal assumption is made that all frames are treated as tagged. Internally, the ASIC
adds a 4-bytes tag to received untagged frames. Though these 4-bytes are not part of the untagged frame received on the wire, they are
included in the rate metering calculation resulting in metering inaccuracy.
Configuring Port-Based Rate Policing
If the interface is a member of a VLAN, you may specify the VLAN for which ingress packets are policed.
• Rate policing ingress traffic on an interface.
INTERFACE mode
rate police
The following example shows configuring rate policing.
Dell#config t
Dell(conf)#interface tengigabitethernet 1/2
Dell(conf-if)#rate police 100 40 peak 150 50
Dell(conf-if)#end
Dell#
Configuring Port-Based Rate Shaping
Rate shaping buffers, rather than drops, traffic exceeding the specified rate until the buffer is exhausted. If any stream exceeds the
configured bandwidth on a continuous basis, it can consume all of the buffer space that is allocated to the port.
• Apply rate shaping to outgoing traffic on a port.
INTERFACE mode
rate shape
• Apply rate shaping to a queue.
QoS Policy mode
Quality of Service (QoS)
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