The 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.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-207102	SRG-NET-000018-RTR-000006	SV-207102r604135_rule		Low

Description
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.

STIG	Date
Router Security Requirements Guide	2021-03-16

Details

Check Text ( C-7363r382151_chk )
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. 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.

Fix Text (F-7363r382152_fix)
Configure all ASBRs to deny updates received from eBGP peers that do not list their AS number as the first AS in the AS_PATH attribute.