Finding ID | Version | Rule ID | IA Controls | Severity |
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V-216620 | CISC-RT-000770 | SV-216620r917420_rule | Low |
Description |
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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 |
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Cisco IOS Router RTR Security Technical Implementation Guide | 2024-06-06 |
Check Text ( C-17855r917418_chk ) |
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Review the router configuration and verify that a QoS policy has been configured to provide preferred treatment for mission-critical applications. Step 1: Verify that the class-maps are configured to match on DSCP values as shown in the configuration example below. class-map match-all PREFERRED_DATA match ip dscp af33 class-map match-all CONTROL_PLANE match ip dscp cs6 class-map match-all VIDEO match ip dscp af41 class-map match-all VOICE match ip dscp ef class-map match-all C2_VOICE match ip dscp 47 Step 2: Verify that the policy map reserves the bandwidth for each traffic type as shown in the following example: policy-map QOS_POLICY class CONTROL_PLANE priority percent 10 class C2_VOICE priority percent 10 class VOICE priority percent 15 class VIDEO bandwidth percent 25 class PREFERRED_DATA bandwidth percent 25 class class-default bandwidth percent 15 Step 3: Verify that an output service policy is bound to all interfaces as shown in the configuration example below. interface GigabitEthernet1/1 ip address 10.1.15.5 255.255.255.252 service-policy output QOS_POLICY ! interface GigabitEthernet1/2 ip address 10.1.15.8 255.255.255.252 service-policy output QOS_POLICY If the router is not configured to implement a QoS policy in accordance with the QoS DODIN Technical Profile, this is a finding. |
Fix Text (F-17851r917419_fix) |
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Configure to enforce a QoS policy to provide preferred treatment for mission-critical applications. Step 1: Configure class-maps to match on DSCP values as shown in the configuration example below. R5(config)#class-map match-all PREFERRED_DATA R5(config-cmap)#match ip dscp af33 R5(config-cmap)#class-map match-all CONTROL_PLANE R5(config-cmap)#match ip dscp cs6 R5(config-cmap)#class-map match-all VIDEO R5(config-cmap)#match ip dscp af41 R5(config-cmap)#class-map match-all VOICE R5(config-cmap)#match ip dscp ef R5(config-cmap)#class-map match-all C2_VOICE R5(config-cmap)#match ip dscp 47 R5(config-cmap)#exit Step 2: Configure a policy map to be applied to the core-layer-facing interface that reserves the bandwidth for each traffic type as shown in the example below. R5(config)#policy-map QOS_POLICY R5(config-pmap)#class CONTROL_PLANE R5(config-pmap-c)#priority percent 10 R5(config-pmap-c)#class C2_VOICE R5(config-pmap-c)#priority percent 10 R5(config-pmap-c)#class VOICE R5(config-pmap-c)#priority percent 15 R5(config-pmap-c)#class VIDEO R5(config-pmap-c)#bandwidth percent 25 R5(config-pmap-c)#class PREFERRED_DATA R5(config-pmap-c)#bandwidth percent 25 R5(config-pmap-c)#class class-default R5(config-pmap-c)#bandwidth percent 15 R5(config-pmap-c)#exit R5(config-pmap)#exit Step 3: Apply the output service policy to all interfaces as shown in the configuration example below. R5(config)#int g1/1 R5(config-if)#service-policy output QOS_POLICY R5(config-if)#exit R5(config)#int g1/2 R5(config-if)#service-policy output QOS_POLICY R5(config-if)#end |