STIGQter: STIG Summary: Cisco IOS XE Router RTR Security Technical Implementation Guide Version: 2 Release: 2 Benchmark Date: 23 Apr 2021:

The Cisco perimeter router must be configured to not redistribute static routes to an alternate gateway service provider into BGP or an Interior Gateway Protocol (IGP) peering with the NIPRNet or to other autonomous systems.

DISA Rule

SV-216668r531086_rule

Vulnerability Number

V-216668

Group Title

SRG-NET-000019-RTR-000010

Rule Version

CISC-RT-000300

Severity

CAT III

CCI(s)

• CCI-001414 - The information system enforces approved authorizations for controlling the flow of information between interconnected systems based on organization-defined information flow control policies.

Weight

10

Fix Recommendation

This requirement is not applicable for the DODIN Backbone.

Configure the router so that static routes are not redistributed to an alternate gateway into either a BGP or any IGP peering with the NIPRNet or to any other autonomous systems. This can be done by excluding that route in the route-map as shown in the example below:

Step 1: Configure a prefix list for any static routes with the alternate gateway as the next-hop address.

R5(config)#ip prefix-list ISP_PREFIX permit x.x.x.0/24

Step 2: Configure a route map that will deny the state routes to the ISP.

R5(config)#route-map FILTER_ISP_STATIC deny 10
R5(config-route-map)#match ip address prefix-list ISP_PREFIX
R5(config-route-map)#exit
R5(config)#route-map FILTER_ISP_STATIC permit 20
R5(config-route-map)#exit

Step 3: Apply the route-map to the IGP and BGP redistribute static commands as shown in the EIGRP example.

R5(config)#router eigrp 1
R5(config-router)#redistribute static route-map FILTER_ISP_STATIC

Check Contents

This requirement is not applicable for the DODIN Backbone.

Step 1: Review the IGP and BGP configurations. If there are redistribute static statements configured as shown in examples below, proceed to step 2.

OSPF Example:

router ospf 1
log-adjacency-changes
redistribute static subnets
network 0.0.0.0 255.255.255.255 area 0

EIGRP example:

router eigrp 1
network 10.1.15.0 0.0.0.255
redistribute static

RIP example:

router rip
version 2
redistribute static
network 10.0.0.0

BGP example:

router bgp nn
no synchronization
bgp log-neighbor-changes
redistribute static
neighbor x.11.1.7 remote-as nn
neighbor x.11.1.7 password xxxxxxx
no auto-summary

Step 2: Review the static routes that have been configured to determine if any contain the next hop address of the alternate gateway.

If the static routes to the alternate gateway are being redistributed into BGP or any IGP peering to a NIPRNet gateway or any other autonomous system, this is a finding.

Vulnerability Number

V-216668

Documentable

False

Rule Version

CISC-RT-000300

Severity Override Guidance

This requirement is not applicable for the DODIN Backbone.

Step 1: Review the IGP and BGP configurations. If there are redistribute static statements configured as shown in examples below, proceed to step 2.

OSPF Example:

router ospf 1
log-adjacency-changes
redistribute static subnets
network 0.0.0.0 255.255.255.255 area 0

EIGRP example:

router eigrp 1
network 10.1.15.0 0.0.0.255
redistribute static

RIP example:

router rip
version 2
redistribute static
network 10.0.0.0

BGP example:

router bgp nn
no synchronization
bgp log-neighbor-changes
redistribute static
neighbor x.11.1.7 remote-as nn
neighbor x.11.1.7 password xxxxxxx
no auto-summary

Step 2: Review the static routes that have been configured to determine if any contain the next hop address of the alternate gateway.

If the static routes to the alternate gateway are being redistributed into BGP or any IGP peering to a NIPRNet gateway or any other autonomous system, this is a finding.

Check Content Reference

M

Target Key

4028

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