The BGP Cisco ACI must be configured to reject outbound route advertisements for any prefixes belonging to the IP core.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-272080 | CACI-RT-000020 | SV-272080r1113986_rule | CCI-001097 | medium |
| Description | ||||
| Outbound route advertisements belonging to the core can result in traffic either looping or being black holed, or at a minimum, using a nonoptimized path. | ||||
| STIG | Date | |||
| Cisco ACI Router Security Technical Implementation Guide | 2025-06-18 | |||
Details
Check Text (C-272080r1113986_chk)
If this review is for the DODIN Backbone, mark as not applicable.
Verify the router is configured to deny router-advertisements.
apic1(config-tenant-fhs-secpol)# router-advertisement-guard
If the router is not configured to reject outbound route advertisements for prefixes belonging to the IP core, this is a finding.
Fix Text (F-76037r1063636_fix)
Configure the router with FHS to suppress Router Advertisements on all external IPv6-enabled interfaces as shown in the example below. View the FHS requirement in the Layer 2 STIG.
apic1(config-tenant-fhs-secpol)# router-advertisement-guard