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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-256013	ARST-RT-000310	SV-256013r882381_rule		Low

Description

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.

STIG	Date
Arista MLS EOS 4.2x Router Security Technical Implementation Guide	2023-01-17

Details

Check Text ( C-59689r882379_chk )

Step 1: Verify the Arista router class-maps are configured to match on DSCP, protocols, or access control lists (ACLs) that identify traffic types based on ports. router#sh 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: Verify the Arista router policy-map is configured to set DSCP values for the defined class-maps in accordance with the QoS GIG Technical Profile. router#sh run |sec port-channel33 interface Port-Channel33 description L3-Routed-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: Verify an output service policy is bound to all interfaces. router#sh run | section qos interface Vlan33 service-policy type qos input policy3 hardware tcam profile QOS_TEST feature acl port ip sequence 45 key size limit 160 key field dscp dst-ip ip-frag ip-protocol l4-dst-port l4-ops l4-src-port src-ip tcp-control ttl action count drop mirror packet ipv4 forwarding bridged packet ipv4 forwarding routed packet ipv4 forwarding routed multicast packet ipv4 mpls ipv4 forwarding mpls decap packet ipv4 mpls ipv6 forwarding mpls decap packet ipv4 non-vxlan forwarding routed decap packet ipv4 vxlan eth ipv4 forwarding routed decap packet ipv4 vxlan forwarding bridged decap ! feature acl port ip egress mpls-tunnelled-match sequence 100 ! feature acl port ipv6 sequence 25 key field dst-ipv6 ipv6-next-header ipv6-traffic-class l4-dst-port l4-ops-3b l4-src-port src-ipv6-high src-ipv6-low tcp-control action count drop mirror packet ipv6 forwarding bridged packet ipv6 forwarding routed packet ipv6 forwarding routed multicast packet ipv6 ipv6 forwarding routed decap ! feature acl port ipv6 egress sequence 110 key field dst-ipv6 ipv6-next-header ipv6-traffic-class l4-dst-port l4-src-port src-ipv6-high src-ipv6-low tcp-control action count drop packet ipv6 forwarding bridged packet ipv6 forwarding routed ! feature acl port mac sequence 55 key size limit 160 key field dst-mac ether-type src-mac action count drop mirror packet ipv4 forwarding bridged packet ipv4 forwarding routed packet ipv4 forwarding routed multicast packet ipv4 mpls ipv4 forwarding mpls decap packet ipv4 mpls ipv6 forwarding mpls decap packet ipv4 non-vxlan forwarding routed decap packet ipv4 vxlan forwarding bridged decap packet ipv6 forwarding bridged packet ipv6 forwarding routed packet ipv6 forwarding routed decap packet ipv6 forwarding routed multicast packet ipv6 ipv6 forwarding routed decap packet mpls forwarding bridged decap packet mpls ipv4 forwarding mpls packet mpls ipv6 forwarding mpls packet mpls non-ip forwarding mpls packet non-ip forwarding bridged ! Step 4: Verify the Arista router is configured for a minimum of four queues, 0 through 3, for (Port-Channel33) as round robin, with voice strict-priority. The allocated bandwidth is queue (0) 19.6%, queue (1) 39.6%, queue (2) 14.9%, and queue (3) 24.9%. The bandwidth percentages allow 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 - ( - ) 14.8 (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 If the Arista router is not configured to implement a QoS policy in accordance with the QoS DODIN Technical Profile, this is a finding.

Fix Text (F-59632r882380_fix)

Step 1: Configure the Arista router class-maps to match on DSCP Quality of Service 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