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ARST-RT-000320 - The PE router must be configured to enforce a Quality-of-Service (QoS) policy in accordance with the QoS GIG Technical Profile.

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Information

Different applications have unique requirements and toleration levels for delay, jitter, bandwidth, packet loss, and availability. To manage the multitude of applications and services, a network requires a QoS framework to differentiate traffic and provide a method to manage network congestion. The Differentiated Services Model (DiffServ) is based on per-hop behavior by categorizing traffic into different classes and enabling each node to enforce a forwarding treatment to each packet as dictated by a policy.

Packet markings such as IP Precedence and its successor, Differentiated Services Code Points (DSCP), were defined along with specific per-hop behaviors for key traffic types to enable a scalable QoS solution. DiffServ QoS categorizes network traffic, prioritizes it according to its relative importance, and provides priority treatment based on the classification. It is imperative that end-to-end QoS is implemented within the IP core network to provide preferred treatment for mission-critical applications.

NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.

Solution

Configure a QoS policy on each router in accordance with the QoS GIG Technical Profile.

Step 1: Configure the Arista router class-maps to match on DSCP Quality of Service Differentiated Service Code Points (DSCP) values to identify four traffic-class into Class 0 (0-7, 16-38, 40-44, 46-48, 50-63) Class 1 (11) Class 2 (39) Class 3 (15, 49).

router(config)#qos map
qos map dscp 0 1 2 3 4 5 6 7 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 40 41 42 43 44 46 47 48 50 51 52 53 54 55 56 57 58 59 60 61 62 63 to traffic-class 0
qos map dscp 11 to traffic-class 1
qos map dscp 39 to traffic-class 2
qos map dscp 15 49 to traffic-class 3
!

Step 2: Configure the Arista router bandwidth and shape rates based on four queues defined by DSCP and the defined class-maps in accordance with the QoS GIG Technical Profile.

router(config)#interface Port-Channel33
router(config-if-po33)#description PO33->Distro1-QFX5200-32C-100G
 routerport trunk allowed vlan 2100-2102,4033
 routerport mode trunk
 routerport trunk group 4033
 qos trust dscp
 !
 tx-queue 0
 bandwidth percent 20
 !
 tx-queue 1
 bandwidth percent 40
 shape rate 40088888
 !
 tx-queue 2
 bandwidth percent 15
 shape rate 15022222
 !
 tx-queue 3
 bandwidth percent 25
 shape rate 25250000
!

Step 3: Configure the Arista router for queues 0 through 3 for Interface (Port-Channel33) as round robin, with voice strict-priority, and then allocate bandwidth for four queues. queue (0) 19.6%, queue (1) 39.6%, queue (2) 14.9%, and queue (3) 24.9%. allowing for control-plane and protocol management traffic. These configurations allow burst traffic levels and shape rates for maximum outbound traffic bandwidth per queue.

router#sh qos int po33
Port-Channel33:
 Trust Mode: DSCP
 Default COS: 0
 Default DSCP: 0
 Port shaping rate: enabled
 Tx Bandwidth Bandwidth Shape Rate Priority ECN/WRED
 Queue (percent) Guaranteed (units) (units)
 ----------------------------------------------------------------------------------------
 7 - - ( - ) - ( - ) SP D
 6 - - ( - ) - ( - ) SP D
 5 - - ( - ) - ( - ) SP D
 4 - - ( - ) - ( - ) SP D
 3 25 - ( - ) 24.9 (Gbps) SP D
 2 15 - ( - ) 14.9 (Gbps) RR D
 1 40 - ( - ) 39.6 (Gbps) RR D
 0 20 - ( - ) - ( - ) RR D

Legend:
RR -> Round Robin
SP -> Strict Priority
 - -> Not Applicable / Not Configured
 % -> Percentage of reference
ECN/WRED: L -> Queue Length ECN Enabled W -> WRED Enabled D -> Disabled

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Arista_MLS_EOS_4-2x_Y23M02_STIG.zip

Item Details

References: CAT|III, CCI|CCI-001095, Rule-ID|SV-256014r882384_rule, STIG-ID|ARST-RT-000320, Vuln-ID|V-256014

Plugin: Arista

Control ID: 34e28d9d314e17fd2a5895b5cfec0a02fdd135a1bce0cb39a0fff509b2b2cf4d