CISC-RT-000300 - The Cisco perimeter router must be configured to not redistribute static routes to an approved gateway service provider into BGP, an IGP peering with the NIPRNet, or other autonomous systems.

Information

If the static routes to the approved gateway are being redistributed into an Exterior Gateway Protocol or Interior Gateway Protocol to a NIPRNet gateway, this could make traffic on NIPRNet flow to that particular router and not to the internet access point routers. This could not only wreak havoc with traffic flows on NIPRNet but could overwhelm the connection from the router to the NIPRNet gateway(s) and cause traffic destined for outside of NIPRNet to bypass the defenses of the internet access points.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

This requirement is not applicable for the DODIN backbone.

Configure the router so that static routes are not redistributed to an approved 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 approved 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

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Cisco_IOS_Router_Y25M01_STIG.zip

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-4, CAT|III, CCI|CCI-001414, Rule-ID|SV-216578r1050878_rule, STIG-ID|CISC-RT-000300, STIG-Legacy|SV-105695, STIG-Legacy|V-96557, Vuln-ID|V-216578

Plugin: Cisco

Control ID: 286faa1b2e682519a36b2d1e9c05391ed8a54326a0fc062da08f664adc60285a