The Cisco BGP router must be configured to reject outbound route advertisements for any prefixes belonging to the IP core.
An XCCDF Rule
Description
<VulnDiscussion>Outbound route advertisements belonging to the core can result in traffic either looping or being black holed, or at a minimum, using a non-optimized path.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-216781r531087_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Step 1: Configure a prefix set containing the IP core prefix as shown below.
RP/0/0/CPU0:R2(config)#prefix-set
Step 2: Configure a prefix set containing the current Bogon prefixes as shown below.