Dell S4820T, Configuration Manual

Page: 792 / 1178

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
Example of Configuring an Interface to Honor dot1p Priorities on Ingress Traffic
Dell#configure terminal
Dell(conf)#interface tengigabitethernet 1/1
Dell(conf-if-te-1/1)#service-class dynamic dot1p
Dell(conf-if-te-1/1)#end
Priority-Tagged Frames on the Default VLAN
Priority-tagged frames are 802.1Q tagged frames with 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
Example of the
rate police
Command
Dell#configure terminal
Dell(conf)#interface tengigabitethernet 1/1
Dell(conf-if-te-1/1)#rate police 100 40 peak 150 50
Dell(conf-if-te-1/1)#end
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Quality of Service (QoS)