Configuring MSDP Routing Policy
All routing protocols use the routing table to store the routes that they learn and to determine which routes they advertise in their protocol packets. Routing policy allows you to control which routes the routing protocols store in, and retrieve from, the routing table. For information about routing policy, see the Junos Routing Protocols Configuration Guide.
You can configure routing policy globally, for a group, or for an individual peer:
- Globally for all MSDP peers at the [edit protocols msdp] or [edit logical-systems logical-system-name protocols msdp] hierarchy level.
- For all peers in a group at the [edit protocols msdp group group-name] or [edit logical-systems logical-system-name protocols msdp group group-name] level.
- For an individual peer at the [edit protocols msdp peer address] or [edit logical-systems logical-system-name protocols msdp peer address] level, or the [edit protocols msdp group group-name peer address] or [edit logical-systems logical-system-name protocols msdp group group-name peer address] level.
If you configure routing policy at the group level, each individual peer in a group inherits the group's routing policy.
To apply policies to source-active messages being imported into the source-active cache from MSDP, include the import statement, listing the names of one or more policy filters to be evaluated. See Table 1 for a list of match conditions.
Table 1: MSDP Source-Active Message Filter Match Conditions
Match Condition | Matches On |
|---|---|
interface | Router interface or interfaces specified by name or IP address |
neighbor | Neighbor address (the source address in the IP header of the source-active message) |
route-filter | Multicast group address embedded in the source-active message |
source-address-filter | Multicast source address embedded in the source-active message |
If you specify more than one policy, they are evaluated in the order specified, from first to last, and the first matching policy is applied to the route. If no match is found, MSDP shares with the routing table only those routes that were learned from MSDP routers.
To apply policies to source-active messages being exported from the source-active cache into MSDP, include the export statement, listing the names of one or more policies to be evaluated. If you specify more than one policy, they are evaluated in the order specified, from first to last, and the first matching policy is applied to the source-active cache entry. If no match is found, the default MSDP export policy is applied to entries in the source-active cache.
