The Arista Multicast Source Discovery Protocol (MSDP) router must be configured to only accept MSDP packets from known MSDP peers.

An XCCDF Rule

Description

MSDP peering with customer network routers presents additional risks to the DISN Core, whether from a rogue or misconfigured MSDP-enabled router. To guard against an attack from malicious MSDP traffic, the receive path or interface filter for all MSDP-enabled RP routers must be configured to only accept MSDP packets from known MSDP peers.

ID: SV-256047r882483_rule
Version: ARST-RT-000680
Severity: Medium
References: CCI-002403
Updated: 5 days ago

Remediation Templates

Ensure the receive path or interface filter for all Arista MSDP routers only accepts MSDP packets from known MSDP peers.

Step 1: Configure the MSDP peers.

LEAF-1A(config)#router msdp
LEAF-1A(config-router-msdp)#  peer 10.11.12.2LEAF-1A(config-router-msdp)#  peer 10.22.12.2
  
Step 2: Configure the access-list inbound on MSDP peering interfaces. MSDP uses TCP port 639.

LEAF-1A(config-router-msdp-peer-10.22.12.2)#ip access-list MSDP_FILTER
LEAF-1A(config-acl-MSDP_FILTER)#  10 permit tcp host 10.1.12.2 host 10.11.17.9 eq 639
LEAF-1A(config-acl-MSDP_FILTER)#  20 permit udp host 10.1.12.2 host 10.11.17.9 eq 500
LEAF-1A(config-acl-MSDP_FILTER)#  30 permit udp 10.11.17.9 eq 500 host 10.1.12.2 
LEAF-1A(config-acl-MSDP_FILTER)#  40 deny ip any any log

Step 3: Apply the ACL on the interface.

LEAF-1A(config-acl-MSDP_FILTER)#interface ethernet 3
LEAF-1A(config-if-Et3)# ip access-group MSDP_FILTER in

The Arista Multicast Source Discovery Protocol (MSDP) router must be configured to only accept MSDP packets from known MSDP peers.

Description

Remediation Templates

A Manual Procedure