The BGP router must be configured to limit the prefix size on any inbound route advertisement to /24 or the least significant prefixes issued to the customer.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-207157 | SRG-NET-000362-RTR-000118 | SV-207157r856641_rule | CCI-002385 | low |
| Description | ||||
| The effects of prefix de-aggregation can degrade router performance due to the size of routing tables and also result in black-holing legitimate traffic. Initiated by an attacker or a misconfigured router, prefix de-aggregation occurs when the announcement of a large prefix is fragmented into a collection of smaller prefix announcements. | ||||
| STIG | Date | |||
| Router Security Requirements Guide | 2024-05-28 | |||
Related Frameworks
2 paths across 2 frameworks
Related Frameworks
NIST 800-531 mapping
SC-5
1.00
- DISA · 5 · disa_xccdf · related
- DISA · 2025-01-23 · disa_cci_list · equivalent
CCI1 mapping
CCI-002385
1.00
- DISA · 5 · disa_xccdf · related
Details
Check Text (C-207157r856641_chk)
This requirement is not applicable for the DODIN Backbone.
Review the router configuration to verify that there is a filter to reject inbound route advertisements that are greater than /24 or the least significant prefixes issued to the customer, whichever is larger.
If the router is not configured to limit the prefix size on any inbound route advertisement to /24 or the least significant prefixes issued to the customer, this is a finding.
Fix Text (F-7418r382500_fix)
Ensure all eBGP routers are configured to limit the prefix size on any route advertisement to /24 or the least significant prefixes issued to the customer.