CISC-RT-000520 - The Cisco BGP router must be configured to reject outbound route advertisements for any prefixes that do not belong to any customers or the local autonomous system (AS).

Information

Advertisement of routes by an autonomous system for networks that do not belong to any of its customers pulls traffic away from the authorized network. This causes a denial of service (DoS) on the network that allocated the block of addresses and may cause a DoS on the network that is inadvertently advertising it as the originator. It is also possible that a misconfigured or compromised router within the GIG IP core could redistribute IGP routes into BGP, thereby leaking internal routes.

Solution

This requirement is not applicable for the DODIN Backbone.

Step 1: Configure a prefix list for containing all customer and local AS prefixes as shown in the example below.

R1(config)#ip prefix-list CE_PREFIX_ADVERTISEMENTS permit x.13.1.0/24 le 32
R1(config)#ip prefix-list CE_PREFIX_ADVERTISEMENTS permit x.13.2.0/24 le 32
R1(config)#ip prefix-list CE_PREFIX_ADVERTISEMENTS permit x.13.3.0/24 le 32
R1(config)#ip prefix-list CE_PREFIX_ADVERTISEMENTS permit x.13.4.0/24 le 32
...
...
...
R1(config)#ip prefix-list CE_PREFIX_ADVERTISEMENTS deny 0.0.0.0/0 ge 8

Item Details

Audit Name: DISA Cisco IOS Router RTR STIG v3r4

Category: ACCESS CONTROL

Plugin: Cisco

Control ID: 7e949e4a7f2115fc0b497708bf58dec17ce7eed5262b960b9b7ca0f2fbafff1e

Detections

Analytics

CISC-RT-000520 - The Cisco BGP router must be configured to reject outbound route advertisements for any prefixes that do not belong to any customers or the local autonomous system (AS).

Information

Solution

See Also

Item Details