The Nokia Multicast Source Discovery Protocol (MSDP) router must be configured to filter received source-active multicast advertisements for any undesirable multicast groups and sources.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-283850 | NOKI-RT-000320 | SV-283850r1203799_rule | CCI-001368 | low |
| Description | ||||
| The interoperability of Border Gateway Protocol (BGP) extensions for interdomain multicast routing and MSDP enables seamless connectivity of multicast domains between autonomous systems. Multiprotocol BGP (MP-BGP) advertises the unicast prefixes of the multicast sources used by Protocol Independent Multicast (PIM) routers to perform Reverse Path Forwarding (RPF) checks and build multicast distribution trees. MSDP is a mechanism used to connect multiple PIM sparse-mode domains, allowing RPs from different domains to share information about active sources. When Rendezvous Points (RPs) in peering multicast domains hear about active sources, they can pass that information on to their local receivers, thereby allowing multicast data to be forwarded between the domains. Configuring an import policy to block multicast advertisements for reserved, Martian, single-source multicast, and any other undesirable multicast groups, as well as any source-group (S, G) states with Bogon source addresses, would assist in avoiding unwanted multicast traffic from traversing the core. | ||||
| STIG | Date | |||
| Nokia Service Router OS 25.x Router Security Technical Implementation Guide | 2026-06-15 | |||
Details
Check Text (C-283850r1203799_chk)
Review the Nokia router configuration to determine if there is export policy to block local source-active multicast advertisements.
Use the command below to view the details of the policy:
- show router policy "MSDP-IMPORT-SA"
entry 10
from
prefix-list "Multicast Group and Source"
exit
action drop
exit
exit
Verify the appropriate "Import Policy" has been applied to msdp peers using the command below:
- show router msdp peer detail | match "Import Policy"
Import Policy : MSDP-IMPORT-SA
Verify an export policy is bound to each MSDP peer.
If no export policy is applied, this is a finding.
Fix Text (F-88320r1203798_fix)
Configure the MSDP router to implement an import policy to block multicast advertisements for undesirable multicast groups and sources.
Configure the prefix-list:
- configure router policy-options
- config>router>policy-options# begin
- config>router>policy-options# prefix-list "Multicast Group and Source"
- config>router>policy-options>prefix-list# prefix 172.200.200.2/32 exact
- config>router>policy-options>prefix-list# prefix 233.0.0.0/8 exact
- config>router>policy-options>prefix-list# exit
Configure the policy statement:
- config>router>policy-options# policy-statement "MSDP-IMPORT-SA"
- config>router>policy-options>policy-statement# entry 10
- config>router>policy-options>policy-statement>entry# from prefix-list "Multicast Group and Source"
- config>router>policy-options>policy-statement>entry# action drop
- config>router>policy-options>policy-statement>entry>action# exit
- config>router>policy-options>policy-statement>entry# exit
- config>router>policy-options>policy-statement# default-action accept
- config>router>policy-options>policy-statement>default-action# exit
- config>router>policy-options>policy-statement# exit
- config>router>policy-options# commit
- config>router>policy-options# exit all
Apply the import policy:
- configure router msdp peer 1.1.1.1 import "MSDP-IMPORT-SA"