The Arista BGP router must be configured to reject inbound route advertisements for any prefixes belonging to the local autonomous system (AS).
An XCCDF Rule
Description
<VulnDiscussion>Accepting route advertisements belonging to the local AS can result in traffic 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-255989r882309_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Configure Arista eBGP routers to reject inbound route advertisements for prefixes that are not allocated to that specific customer.
Step 1: Configure the prefix-list to reject inbound route advertisements belonging to the local AS.
router(config)#ip prefix-list LOCAL_SCOPE_BOUNDARY
router(config-ip-pfx)#seq 10 deny 10.12.0.0/16