The Juniper BGP router must be configured to reject outbound route advertisements for any prefixes belonging to the IP core.

An XCCDF Rule

Description

<VulnDiscussion>Outbound route advertisements belonging to the core can result in traffic either looping or being black holed, or at a minimum, using a non-optimized path.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>

ID: SV-217057r604135_rule
Severity: Medium
References: CCI-001097
Updated: 17 days ago

Configure the router to filter outbound route advertisements belonging to the IP core.

Configure a prefix list containing prefixes belonging to the IP core.

[edit policy-options]
set prefix-list CORE_PREFIX x.x.x.x/16
Configure a policy-statement to filter BGP route advertisements that will exclude core prefixes.

[edit policy-options]
set policy-statement BGP_ADVERTISE_POLICY term EXCLUDE_CORE from prefix-list CORE_PREFIX
set policy-statement BGP_ADVERTISE_POLICY term EXCLUDE_CORE then reject
set policy-statement BGP_ADVERTISE_POLICY term INCLUDE_OTHER then accept

Configure an export statement referencing the advertise policy on all external BGP peer groups as shown in the example below.

[edit protocols bgp group GROUP_AS4]
set export BGP_ADVERTISE_POLICY

The Juniper BGP router must be configured to reject outbound route advertisements for any prefixes belonging to the IP core.

Description

Remediation - Manual Procedure