The Juniper BGP router must be configured to use its loopback address as the source address for iBGP peering sessions.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-254060	JUEX-RT-000880	SV-254060r844213_rule		Low

Description
Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of the BGP routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the network management subnet since the source addresses will be from the range used for loopback interfaces instead of a larger range of addresses used for physical interfaces. Log information recorded by authentication and syslog servers will record the router’s loopback address instead of the numerous physical interface addresses. When the loopback address is used as the source for eBGP peering, the BGP session will be harder to hijack since the source address to be used is not known globally—making it more difficult for a hacker to spoof an eBGP neighbor. By using traceroute, a hacker can easily determine the addresses for an eBGP speaker when the IP address of an external interface is used as the source address. The routers within the iBGP domain should also use loopback addresses as the source address when establishing BGP sessions.

Description

Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of the BGP routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the network management subnet since the source addresses will be from the range used for loopback interfaces instead of a larger range of addresses used for physical interfaces. Log information recorded by authentication and syslog servers will record the router’s loopback address instead of the numerous physical interface addresses. When the loopback address is used as the source for eBGP peering, the BGP session will be harder to hijack since the source address to be used is not known globally—making it more difficult for a hacker to spoof an eBGP neighbor. By using traceroute, a hacker can easily determine the addresses for an eBGP speaker when the IP address of an external interface is used as the source address. The routers within the iBGP domain should also use loopback addresses as the source address when establishing BGP sessions.

STIG	Date
Juniper EX Series Switches Router Security Technical Implementation Guide	2023-03-23

Details

Check Text ( C-57512r844211_chk )
Review the router configuration to verify that a loopback address has been configured. Verify that a loopback interface is used as the source address for all iBGP sessions. bgp { group iBGP { type internal; local-interface lo0.0; : } } If the router does not use its loopback address as the source address for all iBGP sessions, this is a finding.

Fix Text (F-57463r844212_fix)
Ensure that the router’s loopback address is used as the source address when originating traffic. set protocols bgp group type internal set protocols bgp group local-interface lo0.0