Synchronization of multicast information using bicasting

Abstract

Techniques that enable a network device such as a router to provide multicast routing services without interruption. Techniques are provided for using bicasting to synchronize multicast information maintained by a first processor and multicast information maintained by a second processor. A multicast protocol related event of packet is sent to both a first processor operating in active mode and a second processor operating in standby mode. Each processor then updates its multicast information based upon the bicasted event or packet.

What is claimed is: 
     
         1 . A method comprising:
 selectively bicasting a multicast protocol-related packet, received at a processing component of a network device, to a first processor and a second processor based upon a multicast protocol-related packet type, wherein selectively bicasting comprises:   upon determining the multicast protocol-related packet to be of a first type,
 sending, from the processing component, the multicast protocol-related packet to the first processor and a copy of the multicast protocol-related packet to the second processor; 
   updating, by the first processor, first multicast information maintained by the first processor based upon the multicast protocol-related packet received by the first processor; and   updating, by the second processor, second multicast information maintained by the second processor based upon the copy of the multicast protocol-related packet received by the second processor.   
     
     
         2 . The method of  claim 1  wherein the multicast protocol-related packet is a Protocol Independent Multicast (PIM) packet. 
     
     
         3 . The method of  claim 2  wherein the first multicast information updated by the first processor comprises information related to neighbors of the network device that support PIM protocol. 
     
     
         4 . The method of  claim 1  wherein the multicast protocol-related packet is an Internet Group Membership Protocol (IGMP) packet. 
     
     
         5 . The method of  claim 4  wherein the first multicast information updated by the first processor comprises information related to the IGMP. 
     
     
         6 . The method of  claim 1  further comprising:
 communicating update information from the first processor to the second processor, the update information comprising information indicative of a change made to the first multicast information; and 
 updating the second multicast information based upon the update information. 
 
     
     
         7 . The method of  claim 1 , wherein the first processor is configurable to operate in active mode, the first processor performing a set of multicast routing-related functions in the active mode and the second processor is configurable to operate in standby mode, the second processor not performing the set of multicast routing-related functions in the standby mode. 
     
     
         8 . A network device comprising:
 a processing component;   a first processor and a second processor;
 wherein the processing component is operable to determine whether a multicast protocol-related packet is of a first type, and upon determining that the multicast-protocol related packet is of the first type, to send the multicast protocol-related packet to the first processor, and a copy of the multicast protocol-related packet to the second processor; 
   wherein the first processor is further configurable to:
 receive, from the processing component, the multicast protocol-related packet; and 
 update first multicast information maintained by the first processor based upon the multicast protocol-related packet received by the first processor, the first multicast information used by the first processor for performing the set of multicast routing-related functions; 
   wherein the second processor is further configurable to:
 receive, from the processing component, a copy of the multicast protocol-related packet; and 
 update second multicast information maintained by the second processor based upon the copy of the multicast protocol-related packet received by the second processor. 
   
     
     
         9 . The network device of  claim 8  further comprising a linecard, wherein the linecard comprises the processing component. 
     
     
         10 . The network device of  claim 8  wherein the multicast protocol-related packet is a Protocol Independent Multicast (PIM) packet. 
     
     
         11 . The network device of  claim 10  wherein the first multicast information updated by the first processor comprises information related to neighbors of the network device that support PIM protocol. 
     
     
         12 . The network device of  claim 8  wherein the multicast protocol-related packet is an Internet Group Membership Protocol (IGMP) packet. 
     
     
         13 . The network device of  claim 12  wherein the first multicast information updated by the first processor comprises information related to the IGMP. 
     
     
         14 . The network device of  claim 8  wherein:
 the first processor is configurable to communicate update information to the second processor, the update information comprising information indicative of a change made to the first multicast information; and 
 the second processor is configurable to update the second multicast information based upon the update information. 
 
     
     
         15 . The network device of  claim 8 , wherein:
 the first processor is configurable to operate in an active mode, wherein the first processor is configurable to perform a set of multicast routing-related functions in the active mode; and   the second processor is configurable to operate in a standby mode when the first processor is operating in the active mode, wherein the second processor is configurable to not perform the set of multicast routing-related functions in the standby mode.