Finding ID | Version | Rule ID | IA Controls | Severity |
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V-96909 | CISC-RT-000300 | SV-106047r1_rule | Low |
Description |
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If the static routes to the alternate 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 it could overwhelm the connection from the router to the NIPRNet gateway(s) and also cause traffic destined for outside of NIPRNet to bypass the defenses of the Internet Access Points. |
STIG | Date |
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Cisco IOS XE Router RTR Security Technical Implementation Guide | 2019-12-20 |
Check Text ( C-95745r1_chk ) |
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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. |
Fix Text (F-102589r2_fix) |
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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 |