The Cisco PE switch must be configured to enforce a Quality-of-Service (QoS) policy to provide preferred treatment for mission-critical applications.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-221129	CISC-RT-000760	SV-221129r917451_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.

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
Cisco NX OS Switch RTR Security Technical Implementation Guide	2023-05-30

Details

Check Text ( C-22844r917449_chk )
Review the switch 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 C2_VOICE match ip dscp af47 class-map match-all VOICE match ip dscp ef class-map match-all VIDEO match ip dscp af41 class-map match-all CONTROL_PLANE match ip dscp cs6 class-map match-all PREFERRED_DATA match ip dscp af33 Step 2: Verify that the policy map reserves the bandwidth for each traffic type as shown in the example below: policy-map QOS_POLICY class C2_VOICE priority percent 10 class VOICE priority percent 15 class VIDEO bandwidth percent 25 class CONTROL_PLANE priority percent 10 class PREFERRED_DATA bandwidth percent 25 class class-default bandwidth percent 15 Step 3: Verify that an output service policy is bound to all interface as shown in the configuration example below: interface Ethernet1/1 ip address 10.1.15.1/30 service-policy output QOS_POLICY ! interface Ethernet1/2 ip address 10.1.15.4/30 service-policy output QOS_POLICY Note: Enclaves must mark or re-mark their traffic to be consistent with the DoDIN backbone admission criteria to gain the appropriate level of service. A general DiffServ principle is to mark or trust traffic as close to the source as administratively and technically possible. However, certain traffic types might need to be re-marked before handoff to the DoDIN backbone to gain admission to the correct class. If such re-marking is required, it is recommended that the re-marking be performed at the CE egress edge. Note: The GTP QOS document (GTP-0009) can be downloaded via the following link: https://intellipedia.intelink.gov/wiki/Portal:GIG_Technical_Guidance/GTG_GTPs/GTP_Development_List If the switch is not configured to enforce a QoS policy in accordance with the QoS GIG Technical Profile, this is a finding.

Check Text ( C-22844r917449_chk )

Review the switch 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 C2_VOICE
match ip dscp af47
class-map match-all VOICE
match ip dscp ef
class-map match-all VIDEO
match ip dscp af41
class-map match-all CONTROL_PLANE
match ip dscp cs6
class-map match-all PREFERRED_DATA
match ip dscp af33

Step 2: Verify that the policy map reserves the bandwidth for each traffic type as shown in the example below:

policy-map QOS_POLICY
class C2_VOICE
priority percent 10
class VOICE
priority percent 15
class VIDEO
bandwidth percent 25
class CONTROL_PLANE
priority percent 10
class PREFERRED_DATA
bandwidth percent 25
class class-default
bandwidth percent 15

Step 3: Verify that an output service policy is bound to all interface as shown in the configuration example below:

interface Ethernet1/1
ip address 10.1.15.1/30
service-policy output QOS_POLICY
!
interface Ethernet1/2
ip address 10.1.15.4/30
service-policy output QOS_POLICY

Note: Enclaves must mark or re-mark their traffic to be consistent with the DoDIN backbone admission criteria to gain the appropriate level of service. A general DiffServ principle is to mark or trust traffic as close to the source as administratively and technically possible. However, certain traffic types might need to be re-marked before handoff to the DoDIN backbone to gain admission to the correct class. If such re-marking is required, it is recommended that the re-marking be performed at the CE egress edge.

Note: The GTP QOS document (GTP-0009) can be downloaded via the following link:
https://intellipedia.intelink.gov/wiki/Portal:GIG_Technical_Guidance/GTG_GTPs/GTP_Development_List

If the switch is not configured to enforce a QoS policy in accordance with the QoS GIG Technical Profile, this is a finding.

Fix Text (F-22833r917450_fix)
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: SW1(config-cmap)# class-map match-all C2_VOICE SW1(config-cmap)# match ip dscp 47 SW1(config-cmap)# class-map match-all VOICE SW1(config-cmap)# match ip dscp ef SW1(config-cmap)# class-map match-all VIDEO SW1(config-cmap)# match ip dscp af41 SW1(config-cmap)# class-map match-all CONTROL_PLANE SW1(config-cmap)# match ip dscp cs6 SW1(config-cmap)# class-map match-all PREFERRED_DATA SW1(config-cmap)# match ip dscp af33 SW1(config-cmap)# exit Step 2: Configure a policy map to be applied to the interfaces that reserves the bandwidth for each traffic type as shown in the example below: SW1(config)# policy-map QOS_POLICY SW1(config-pmap-c)# class C2_VOICE SW1(config-pmap-c)# priority percent 10 SW1(config-pmap-c)# class VOICE SW1(config-pmap-c)# priority percent 15 SW1(config-pmap-c)# class VIDEO SW1(config-pmap-c)# bandwidth percent 25 SW1(config-pmap)# class CONTROL_PLANE SW1(config-pmap-c)# priority percent 10 SW1(config-pmap-c)# class PREFERRED_DATA SW1(config-pmap-c)# bandwidth percent 25 SW1(config-pmap-c)# class class-default SW1(config-pmap-c)# bandwidth percent 15 SW1(config-pmap-c)# exit SW1(config-pmap)# exit Step 3: Apply the output service policy to all interfaces as shown in the configuration example below: SW1(config)# int e1/1 SW1(config-if)# service-policy output QOS_POLICY SW1(config-if)# exit SW1(config)# int e1/2 SW1(config-if)# service-policy output QOS_POLICY SW1(config-if)# end

Fix Text (F-22833r917450_fix)

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:

SW1(config-cmap)# class-map match-all C2_VOICE
SW1(config-cmap)# match ip dscp 47
SW1(config-cmap)# class-map match-all VOICE
SW1(config-cmap)# match ip dscp ef
SW1(config-cmap)# class-map match-all VIDEO
SW1(config-cmap)# match ip dscp af41
SW1(config-cmap)# class-map match-all CONTROL_PLANE
SW1(config-cmap)# match ip dscp cs6
SW1(config-cmap)# class-map match-all PREFERRED_DATA
SW1(config-cmap)# match ip dscp af33
SW1(config-cmap)# exit

Step 2: Configure a policy map to be applied to the interfaces that reserves the bandwidth for each traffic type as shown in the example below:

SW1(config)# policy-map QOS_POLICY
SW1(config-pmap-c)# class C2_VOICE
SW1(config-pmap-c)# priority percent 10
SW1(config-pmap-c)# class VOICE
SW1(config-pmap-c)# priority percent 15
SW1(config-pmap-c)# class VIDEO
SW1(config-pmap-c)# bandwidth percent 25
SW1(config-pmap)# class CONTROL_PLANE
SW1(config-pmap-c)# priority percent 10
SW1(config-pmap-c)# class PREFERRED_DATA
SW1(config-pmap-c)# bandwidth percent 25
SW1(config-pmap-c)# class class-default
SW1(config-pmap-c)# bandwidth percent 15
SW1(config-pmap-c)# exit
SW1(config-pmap)# exit

Step 3: Apply the output service policy to all interfaces as shown in the configuration example below:

SW1(config)# int e1/1
SW1(config-if)# service-policy output QOS_POLICY
SW1(config-if)# exit
SW1(config)# int e1/2
SW1(config-if)# service-policy output QOS_POLICY
SW1(config-if)# end