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The BGP Cisco ACI 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 IDVersionRule IDIA ControlsSeverity
V-272089CACI-RT-000029SV-272089r1114282_ruleCCI-002385low
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.
STIGDate
Cisco ACI Router Security Technical Implementation Guide2025-06-18

Related Frameworks

1 mapping across 4 frameworks
SCF0 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (13) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

MON-01Continuous Monitoring
1.00
MON-01.1Intrusion Detection & Prevention Systems (IDS & IPS)
1.00
MON-01.3Inbound & Outbound Communications Traffic
1.00
MON-01.4System Generated Alerts
1.00
MON-01.8Security Event Monitoring
1.00
NET-01Network Security Controls (NSC)
1.00
NET-02Layered Network Defenses
1.00
SEA-01Secure Engineering Principles
1.00
SEA-02Alignment With Enterprise Architecture
1.00
CAP-01Capacity & Performance Management
0.50

+3 more (top 10 by confidence shown)

NIST 800-530 mappings

No source states a mapping between these directly.

Also reachable in 2 hops (36) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

AC-10Concurrent Session Control
1.00
AC-17(9)Disconnect or Disable Access
1.00
AC-2(4)Automated Audit Actions
1.00
AC-3Access Enforcement
1.00
AC-4Information Flow Enforcement
1.00
AC-6(9)Log Use of Privileged Functions
1.00
AU-12Audit Record Generation
1.00
AU-3Content of Audit Records
1.00
AU-5Response to Audit Logging Process Failures
1.00
CM-11(2)Software Installation with Privileged Status
1.00

+26 more (top 10 by confidence shown)

CCI1 mapping
CCI-002385
1.00
NIST CSF 2.00 mappings

No source states a mapping between these directly.

Also reachable in 3 hops (3) derived by us, not asserted by any source

Each of these is a route we composed by chaining published mappings. No publisher states a relationship between the two endpoints.

DE.CM-01
1.00
PR.IR-01
1.00
PR.IR-04
0.50

Who does this work

12 NICE work roles and 9 EC-Council certifications.

This is an inference across published mappings, not a single claim by anyone. This check maps to a control, which maps to a Cybersecurity Framework outcome, which NIST assigns to the work roles below. EC-Council separately maps its certifications to those same roles.

A certification prepares someone for a role. It is not evidence that a holder is qualified, and neither NIST nor EC-Council has stated that any certification here addresses this check.

Work-role assignments published by NIST (NICE Framework Components 2.2.0 and the CSF 2.0 OLIR crosswalk). Certification mappings published by EC-Council.

Details

Check Text (C-272089r1114282_chk)

Review the configuration of the RP to verify it is rate limiting the number of PIM register messages. tenant <tenant_name> prefix-list ALLOW_SUBNET ip prefix 10.0.0.0/24 permit match-rule filter_rule match prefix allow_subnet tenant <tenant_name> l3extInstP <l3extInstP_name> route-profile FILTER_PROFILE 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-76046r1114281_fix)

Configure the router to limit the prefix size on any route advertisement to /24 or the least significant prefixes issued to the customer. Create a "match rule" within a "route profile" by specifying a prefix list, which is then applied to the desired L3Out (external routed network) to filter BGP routes based on the prefixes defined in the list. The route profile is applied to a specific L3Out (external routed network) to control which prefixes are advertised or accepted from external networks. 1. Configure a prefix list to reject any prefix that is longer than /24. tenant <tenant_name> prefix-list ALLOW_SUBNET ip prefix 10.0.0.0/24 permit 2. Create a route profile named "filter_profile". tenant <tenant_name> route-profile FILTER_PROFILE match-rule filter_rule match prefix allow_subnet 3. Apply the route profile to an L3Out. tenant <tenant_name> l3extInstP <l3extInstP_name> route-profile FILTER_PROFILE