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V-269854

CAT III (Low)

The Dell OS10 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.

Rule ID

SV-269854r1137898_rule

STIG

Dell OS10 Switch Router Security Technical Implementation Guide

Version

V1R2

CCIs

CCI-001368

Discussion

Verifying the path a route has traversed will ensure the IP core is not used as a transit network for unauthorized or possibly even internet traffic. All autonomous system boundary routers (ASBRs) must ensure updates received from eBGP peers list their AS number as the first AS in the AS_PATH attribute.

Check Content

By default, the Dell OS10 Router rejects route advertisements from BGP peers that do not list their AS number as the first AS in the AS_PATH attribute. Verify that this behavior has not been disable by reviewing the running-configuration of BGP: 

OS10# show running-configuration bgp
!
router bgp 100
no enforce-first-as
…
!

Verify that "no enforce-first-as" has not been configured for BGP. If "no enforce-first-as" has been configured, this is a finding.

Fix Text

Configure the BGP router to reject route advertisements from BGP peers that do not list their AS number as the first AS in the AS_PATH attribute.

OS10# configure terminal
OS10 (config)# router bgp 100
OS10(config-router-bgp-100)# enforce-first-as
OS10(config-router-bgp-100)# end