ARST-RT-000690 - The Arista BGP router must be configured to use its loopback address as the source address for iBGP peering sessions.

Information

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.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

Ensure the Arista router's loopback address is used as the source address when originating traffic.

Step 1: Configure the Loopback interface.

LEAF-1A(config)#interface Loopback0
LEAF-1A(config-if-Lo0)#ip address 10.1.1.1/32

Step 2: Configure the loopback interface as source for all iBGP sessions.

router bgp 65001
LEAF-1A(config-router-bgp)#
LEAF-1A(config-router-bgp)#neighbor Peer_Leaf peer group
LEAF-1A(config-router-bgp)#Peer_Leaf remote-as 65001
LEAF-1A(config-router-bgp)#Peer_Leaf update-source Loopback0
LEAF-1A(config-router-bgp)#10.2.2.2 peer group Peer_Leaf

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Arista_MLS_EOS_4-2x_Y24M07_STIG.zip

Item Details

Category: CONTINGENCY PLANNING

References: 800-53|CP-8, CAT|III, CCI|CCI-004931, Rule-ID|SV-256048r991789_rule, STIG-ID|ARST-RT-000690, Vuln-ID|V-256048

Plugin: Arista

Control ID: de8b274bfdc2f487660fbc55ea3887446cb9e24a1201344db5d58eb847c468f6