The Arista BGP router must be configured to reject outbound route advertisements for any prefixes belonging to the IP core.
An XCCDF Rule
Description
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.
- ID
- SV-256020r882402_rule
- Version
- ARST-RT-000390
- Severity
- Medium
- References
- Updated
Remediation Templates
A Manual Procedure
Configure all eBGP Arista routers to filter outbound route advertisements belonging to the IP core.
Step 1: Configure an outbound route advertise filter and configure CE Arista MLS to advertise the filter to IP Core PE (100.1.0.128). Also configure an IP prefix list named FILTER_OUT to specify the 172.16.1.0/24 subnet for outbound route advertisements filtering.
LEAF-1A(config)#ip prefix-list FILTER_OUT seq 10 permit 172.16.1.0/24