Method for synchronization of multicast routing table changes with a plurality of multicast routing protocols
View Patent ↗A multicast network device, such as a route may support a plurality of multicast routing protocols. A single multicast routing table may be provided to store the multicast routes for each multicast routing protocol and a selected set of unicast routes from a unicast routing table. In order to synchronize route changes in the multicast routing table with the plurality of multicast routing protocols, a route ID value is assigned to each route in the multicast routing table. Each multicast routing protocol is assigned a bookmark in a route change queue, where the bookmark is assigned the route ID value of the last route processed by the multicast routing protocol. When a route is changed, the route is assigned a new route ID value and stored in the route change queue. A multicast routing protocol may determine if a route change has occurred by comparing its bookmark to the highest route ID value in the route change queue.
1. A method for synchronizing a route change in a routing table for a plurality of multicast routing protocols in a network device in a communication network device, the method comprising:
assigning a route ID value to each route in the routing table;
assigning a bookmark in a route change queue to each multicast routing protocol, the bookmark having a value equivalent to the route ID value of the last route processed by the multicast routing protocol, wherein the route change queue is separate from the routing table, and wherein the route change queue is shared across the plurality of multicast routing protocols;
assigning a new route ID value to each route changed in the routing table;
independently storing each route changed in both the routing table and the route change queue; and
comparing the bookmark value of each multicast routing protocol to the highest route ID value in the route change queue.
2. A method according to claim 1 , wherein the route change is the addition of a new route to the routing table.
3. A method according to claim 1 , wherein the route change is the deletion of a route from the routing table.
4. A method according to claim 1 , wherein the route change is updating a route in the routing table.
5. A method according to claim 1 , further including processing routes in the route change queue with route ID values greater than the bookmark value of the multicast routing protocol.
6. A method according to claim 1 , wherein each route changed comprises a route entry for a route in the routing table for the plurality of multicast routing protocols, the route entry comprising:
an address for the route source network;
an address for the next hop of the route;
an address for the next bop interface of the route;
a route state value for indicating the current state of the route;
a routing protocol identifier for identifying the routing protocol associated with the route; and
the new route ID value, wherein the new route ID value is further for determining when the route entry has been processed by each of the plurality of multicast routing protocols.
7. A computer program product for use on a computer system for synchronizing a route change in a routing table with a plurality of multicast routing protocols in a network device in a communication network, the computer program product comprising a computer useable medium having a computer readable program code thereon, the computer readable program code including:
program code for assigning a route ID value to each route in the routing table;
program code for assigning a bookmark in a route change queue to each multicast routing protocol, the bookmark having a value equivalent to the route ID value of the last route processed by the multicast routing protocol, wherein the route change queue is separate from the routing table, and wherein the route change queue is shared across the plurality of multicast routing protocols;
program code for assigning a new route ID value to each route changed in the routing table;
program code for independently storing each route changed in both the routing table and the route change queue; and
program code for comparing the bookmark value of each multicast routing protocol to the highest route ID value in the route change queue.
8. A computer program product according to claim 7 , wherein the route change is the addition of a new route to the routing table.
9. A computer program product according to claim 7 , wherein the route change is the deletion of a route from the routing table.
10. A computer program product according to claim 7 , wherein the route change is updating a route in the routing table.
11. A computer program product according to claim 7 , further including program code for processing routes in the route change queue with route ID values greater than the bookmark value of the multicast routing protocol.