STIGQter: STIG Summary: Cisco IOS XE Router RTR Security Technical Implementation Guide Version: 2 Release: 2 Benchmark Date: 23 Apr 2021:

The Cisco BGP router must be configured to reject route advertisements from BGP peers that do not list their autonomous system (AS) number as the first AS in the AS_PATH attribute.

DISA Rule

SV-216692r531086_rule

Vulnerability Number

V-216692

Group Title

SRG-NET-000018-RTR-000006

Rule Version

CISC-RT-000540

Severity

CAT III

CCI(s)

• CCI-000032 - The information system enforces information flow control using organization-defined security policy filters as a basis for flow control decisions for organization-defined information flows.

Weight

10

Fix Recommendation

Configure the router to deny updates received from eBGP peers that do not list their AS number as the first AS in the AS_PATH attribute.

R1(config)#router bgp xx
R1(config-router)#bgp enforce-first-as

Check Contents

Review the router configuration to verify the router is configured to deny updates received from eBGP peers that do not list their AS number as the first AS in the AS_PATH attribute.

By default, Cisco IOS enforces the first AS in the AS_PATH attribute for all route advertisements. Review the router configuration to verify that the command no bgp enforce-first-as is not configured.

router bgp xx
no synchronization
no bgp enforce-first-as

If the router is not configured to reject updates from peers that do not list their AS number as the first AS in the AS_PATH attribute, this is a finding.

Vulnerability Number

V-216692

Documentable

False

Rule Version

CISC-RT-000540

Severity Override Guidance

Review the router configuration to verify the router is configured to deny updates received from eBGP peers that do not list their AS number as the first AS in the AS_PATH attribute.

By default, Cisco IOS enforces the first AS in the AS_PATH attribute for all route advertisements. Review the router configuration to verify that the command no bgp enforce-first-as is not configured.

router bgp xx
no synchronization
no bgp enforce-first-as

If the router is not configured to reject updates from peers that do not list their AS number as the first AS in the AS_PATH attribute, this is a finding.

Check Content Reference

M

Target Key

4028

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