Deployment Guide

Applying Layer 2 Match Criteria on a Layer 3 Interface
To process Layer 3 packets that contain a dot1p (IEEE 802.1p) VLAN Layer 2 header, configure VLAN tags on a Layer 3
port interface which is configured with an IP address but has no VLAN associated with it. You can also 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
DellEMC(conf)# interface fo 1/49/1
INTERFACE mode
DellEMC(conf-if-fo-1/49/1)# 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
DellEMC(conf)# policy-map-input l2p layer2
3. Apply the Layer 2 policy on a Layer 3 interface.
INTERFACE mode
DellEMC(conf-if-fo-1/49/1)# 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 EMC 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 frequently. The receive buffer must be large enough to save all data that
is received when the system processes a PFC PAUSE frame.
You can use the service-class buffer shared-threshold-weight queue0 ... queue7 number command in
Interface Configuration mode to specify the threshold weight for the shared buffer for each of the queues per port.
1. Create a 10-Gigabit Ethernet interface.
DellEMC(conf)#interface TenGigabitEthernet 1/1/1
2. Configure the threshold weight of the shared buffer for the queues you want. In this example, this setting is configured for
queues 5 and 7.
DellEMC(conf-if-te-1/1/1)#Service-class buffer shared-threshold-weight queue5 4 queue7 6
722
Quality of Service (QoS)