MSDP

MSDP (Multicast Source Discovery Protocol) is an inter-domain multicast protocol that enables the sharing of active multicast source information between Protocol Independent Multicast Sparse Mode (PIM-SM) domains with different Rendezvous Points (RPs). It allows multicast sources in one autonomous system to be discovered by receivers in other autonomous systems by creating peering relationships between MSDP speakers that exchange Source-Active (SA) messages containing multicast source and group information. MSDP is essential for building scalable inter-domain multicast networks, enabling global multicast connectivity while maintaining autonomous control of multicast routing within each domain.

Diagram

Classes

configuration (iosxe.devices)

Name	Type	Constraint	Mandatory	Default Value
msdp	Class	`[msdp]`	No

msdp (iosxe.devices.configuration)

Name	Type	Constraint	Mandatory
originator_id	String		No
passwords	List	`[passwords]`	No
peers	List	`[peers]`	No
vrfs	List	`[vrfs]`	No

passwords (iosxe.devices.configuration.msdp)

Name	Type	Constraint	Mandatory
host	String		Yes
encryption	Integer	min: `0`, max: `7`	No
password	String		Yes

peers (iosxe.devices.configuration.msdp)

Name	Type	Constraint	Mandatory
host	String		Yes
remote_as	Integer	min: `1`, max: `65535`	No
connect_source_interface_type	Choice	`Loopback`	No
connect_source_interface_id	String		No

vrfs (iosxe.devices.configuration.msdp)

Name	Type	Constraint	Mandatory
vrf	String		Yes
originator_id	String		No
passwords	List	`[passwords]`	No
peers	List	`[peers]`	No

By sharing active multicast source information between PIM-SM domains, MSDP enables scalable inter-domain multicast routing and global multicast connectivity.

MSDP Parameters

Key Components:

Originator ID (originator_id): Sets the MSDP originator ID, typically using a loopback interface.
Peers (peers): Defines MSDP peer relationships, including IP address, remote AS, and connect source interface.
Passwords (passwords): Configures per-peer authentication passwords with encryption type.
SA-Filter Lists (sa_filter_in, sa_filter_out): Applies inbound and outbound SA-filters using access lists.
Keepalive Interval (keepalive): Sets the MSDP keepalive interval.
Holdtime (holdtime): Sets the MSDP holdtime interval.
Mesh-Groups (mesh_groups): Configures mesh-groups for MSDP peers.
VRF-Specific Configuration (vrfs): Enables MSDP and configures parameters within specific VRF instances.

Key Parameters Briefly Explained:

originator_id: MSDP originator ID.
peers: MSDP peer configuration.
passwords: Peer authentication settings.
sa_filter_in, sa_filter_out: SA-filter lists.
keepalive: Keepalive interval.
holdtime: Holdtime interval.
mesh_groups: Mesh-group configuration.
vrfs: VRF-specific MSDP settings.

You can use these MSDP parameters to enable inter-domain multicast routing and share active source information between different PIM-SM domains. Customize peer relationships, authentication, and SA-filters to fit your network’s multicast distribution requirements and security policies. Adjusting these parameters lets you tailor how multicast sources are discovered and propagated across autonomous systems.

Sample Configuration

The following configuration describes how to set up MSDP on a Cisco IOS-XE device, including originator ID, peer relationships, authentication, SA-filters, keepalive/holdtime intervals, and VRF-specific settings.

ip msdp originator-id Loopback0
ip msdp password 10.10.10.10 0 Cisco123
ip msdp password 10.20.20.20 7 encryptedPassword456
ip msdp peer 10.10.1.1 remote-as 25000 connect-source Loopback0
ip msdp peer 10.30.30.30 remote-as 30000
ip msdp sa-filter in 10.0.0.0/8 list SA-IN-ACL
ip msdp sa-filter out 10.0.0.0/8 list SA-OUT-ACL
ip msdp keepalive 60
ip msdp holdtime 90
!
ip msdp vrf VRF-MULTICAST
 originator-id Loopback1
 password 172.16.10.10 0 VrfPassword123
 peer 172.16.20.20 remote-as 40000 connect-source Loopback1

Example YAML Code

The following YAML code defines MSDP configuration on an IOS-XE device, including originator ID, peer definitions, passwords, and VRF-specific MSDP settings.

iosxe:
  devices:
    - name: Device1
      configuration:
        msdp:
          originator_id: 192.168.1.1
          passwords:
            - host: 10.10.10.10
              encryption: 0
              password: Cisco123
            - host: 10.20.20.20
              encryption: 7
              password: encryptedPassword456
          peers:
            - host: 10.10.1.1
              remote_as: 25000
              connect_source_interface_type: Loopback
              connect_source_interface_id: "0"
            - host: 10.30.30.30
              remote_as: 30000
          vrfs:
            - vrf: VRF-MULTICAST
              originator_id: 172.16.1.1
              passwords:
                - host: 172.16.10.10
                  encryption: 0
                  password: VrfPassword123
              peers:
                - host: 172.16.20.20
                  remote_as: 40000
                  connect_source_interface_type: Loopback
                  connect_source_interface_id: "1"