Users Guide

configure a VLAN sub-interface on the port interface and apply a policy map that classifies packets using the
dot1p VLAN ID.
To apply an input policy map with Layer 2 match criteria to a Layer 3 port interface, use the service-
policy input policy-name layer 2 command in Interface configuration mode.
To apply a Layer 2 policy on a Layer 3 interface:
1 Configure an interface with an IP address or a VLAN sub-interface
CONFIGURATION mode
Dell(conf)# interface fo 1/4
INTERFACE mode
Dell(conf-if-fo-1/4)# ip address 90.1.1.1/16
2 Configure a Layer 2 QoS policy with Layer 2 (Dot1p or source MAC-based) match criteria.
CONFIGURATION mode
Dell(conf)# policy-map-input l2p layer2
3 Apply the Layer 2 policy on a Layer 3 interface.
INTERFACE mode
Dell(conf-if-fo-1/4)# service-policy input l2p layer2
Managing Hardware Buffer Statistics
The memory management unit (MMU) is 12.2 MB in size. It contains approximately 60,000 cells, each of
which is 208 bytes in size. MMU also has another portion of 3 MB allocated to it. The entire MMU space is
shared across a maximum of 104 logical ports to support the egress admission-control functionality to
implement scheduling and shaping on per-port and per-queue levels. Also, the MMU buffer cells can be used
by each port or queue either as a static partition or as a dynamic partition. With dynamic mode, you can
specify the percentage of available buffer that is utilized by a queue. This dynamic partition or block is set to
be two-thirds of the available buffers for all unicast queues and one-fifth of the available buffers for all
multicast queues on these platforms.
The maximum number of ports, including fan-out, supported is 104 and the maximum number of queues
supported is 21. Analyzing and evaluating buffer statistics enables monitoring of resources and tuning of
allocation of buffers. Max Use count mode provides the maximum values of counters accumulated over a
period of time. Current Use count mode enables you to obtain a snapshot of the counters, at a particular
time, using a triggering utility. The trigger can either be software-based or based on a predetermined
threshold event. Software-based triggers are supported, which are the values derived from the show
command output in the Max Use count mode. In Dell Networking OS Release 9.3(0.0), only the Max Use
count mode of operation is supported for the computation of maximum counter values.
Depending on the buffer space statistical values that you can obtain, you can modify the settings for buffer
area to achieve enhanced reliability and efficiency in the handling of packets. This evaluation and
administration of buffer statistics is useful and important in deployments that experience congestion
Quality of Service (QoS) 802