Check: CISC-RT-000640
Cisco NX OS Switch RTR STIG:
CISC-RT-000640
(in versions v2 r3 through v1 r0.1)
Title
The Cisco PE switch must be configured to have each Virtual Routing and Forwarding (VRF) instance with the appropriate Route Target (RT). (Cat I impact)
Discussion
The primary security model for an MPLS L3VPN as well as a VRF-lite infrastructure is traffic separation. Each interface can only be associated to one VRF, which is the fundamental framework for traffic separation. Forwarding decisions are made based on the routing table belonging to the VRF. Control of what routes are imported into or exported from a VRF is based on the RT. It is critical that traffic does not leak from one COI tenant or L3VPN to another; hence, it is imperative that the correct RT is configured for each VRF.
Check Content
Review the design plan for MPLS/L3VPN to determine what RTs have been assigned for each VRF. Review the switch configuration and verify that the correct RT is configured for each VRF. In the example below, route target 13:13 has been configured for customer 1. vrf context CUST1 address-family ipv4 unicast route-target export 13:13 route-target import 13:13 If there are VRFs configured with the wrong RT, this is a finding.
Fix Text
Configure the switch to have each VRF instance defined with the correct RT. SW1(config)# vrf context CUST1 SW1(config-vrf)# address-family ipv4 unicast SW1(config-vrf-af-ipv4)# route-target import 13:13 SW1(config-vrf-af-ipv4)# route-target export 13:13 SW1(config-vrf-af-ipv4)# end
Additional Identifiers
Rule ID: SV-221118r622190_rule
Vulnerability ID: V-221118
Group Title: SRG-NET-000512-RTR-000006
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-000366 |
The organization implements the security configuration settings. |
Controls
Number | Title |
---|---|
CM-6 |
Configuration Settings |