Virtual network device architecture

Abstract

A network device such as a router or a switch is comprised of a control module and a plurality of physical line cards. The control module includes a control processor virtual machine, a plurality of route processing virtual machines and one or more instances of a line card virtual machine. The line card virtual machine operates to receive routing information base update information, to modify the routing information base according to the update information and to update each instance of a plurality of forwarding information bases included on each of the physical line cards.

What is claimed is: 
     
         1 . A networking device, comprising:
 a chassis;   a backplane housed in the chassis;   a physical line card housed in the chassis and coupled to the backplane, wherein the physical line card includes at least one port and a physical line card database; and   a virtualization subsystem housed in the chassis and coupled to the physical line card through the backplane, wherein the virtualization subsystem is configured to:
 determine a database update; 
 determine that the database update provides modifications to information in the physical line card database and, in response, update information in the physical line card database using the database update; and 
 perform, using information in the physical line card database, layer 2 and layer 3 protocol processing for the physical line card to process and forward a packet that was received through the at least one port such that the packet is forwarded through the at least one port. 
   
     
     
         2 . The network device of  claim 1 , wherein the physical line card is free of a layer 2 protocol processing system. 
     
     
         3 . The network device of  claim 1 , wherein the physical line card is free of a layer 3 protocol processing system. 
     
     
         4 . The network device of  claim 1 , wherein the virtualization subsystem is configured to:
 execute at least one network protocol to receive network information through a network; and   use the network information to determine the database update.   
     
     
         5 . The network device of  claim 1 , wherein the physical line card database includes a layer 2 forwarding table. 
     
     
         6 . The network device of  claim 1 , wherein the physical line card database includes a layer 3 forwarding table. 
     
     
         7 . The network device of  claim 1 , wherein the database update is provided in a virtualization subsystem database in the virtualization subsystem, and wherein the virtualization subsystem includes at least one agent that is configure to:
 determine that the database update provides modifications to information in the physical line card database and update information in the physical line card database using the database update in response to determining that the database update provides modifications to information in the virtualization subsystem database.   
     
     
         8 . A networking system, comprising:
 a backplane;   a plurality of physical line cards coupled to the backplane, wherein each of the plurality of physical line cards includes at least one port and a physical line card database; and   a virtualization subsystem coupled to the plurality of physical line cards through the backplane, wherein the virtualization subsystem is configured to:
 determine a database update; 
 determine that the database update provides modifications to information in a respective physical line card database included in each of a subset of the plurality of physical line cards; 
 update, using the database update, information in the respective physical line card database included in each of the subset of the plurality of physical line cards; and 
 perform, using information in the respective physical line card database in each of the plurality of physical line cards, layer 2 and layer 3 protocol processing for each of the plurality of physical line cards to process and forward packets that are received by those physical line cards such that the packets are forwarded from those physical line cards. 
   
     
     
         9 . The networking system of  claim 8 , wherein each of the plurality of physical line cards is free of a layer 2 protocol processing system. 
     
     
         10 . The networking system of  claim 8 , wherein each of the plurality of physical line cards is free of a layer 3 protocol processing system. 
     
     
         11 . The networking system of  claim 8 , wherein the virtualization subsystem is configured to:
 execute at least one network protocol to receive network information through a network; and   use the network information to determine the database update.   
     
     
         12 . The networking system of  claim 8 , wherein each physical line card database includes a layer 2 forwarding table. 
     
     
         13 . The networking system of  claim 8 , wherein each physical line card database includes a layer 3 forwarding table. 
     
     
         14 . The networking system of  claim 8 , wherein the database update is provided in a virtualization subsystem database in the virtualization subsystem, and wherein the virtualization subsystem includes at least one agent that is configure to:
 determine that the database update provides modifications to information in the respective physical line card database included in each of the subset of the plurality of physical line cards and update information in the respective physical line card database in each of the subset of the plurality physical line cards using the database update in response to determining that the database update provides modifications to information in the virtualization subsystem database.   
     
     
         15 . A method for forwarding packets, comprising:
 determining, using a virtualization subsystem in a networking device, a database update;   determining, using the virtualization subsystem, that the database update provides modifications to information in a physical line card database included in a physical line card in the networking device;   updating, by the virtualization subsystem using the database update, information in the physical line card database included in the physical line card; and   performing, by the virtualization subsystem using information in the physical line card database included in the physical line card, layer 2 and layer 3 protocol processing for the physical line card to process and forward a packet that is received by the physical line card such that the packet is forwarded from the physical line card.   
     
     
         16 . The method of  claim 15 , wherein the physical line card is free of a layer 2 protocol processing system. 
     
     
         17 . The method of  claim 15 , wherein the physical line card is free of a layer 3 protocol processing system. 
     
     
         18 . The method of  claim 15 , further comprising:
 executing, by the virtualization subsystem, at least one network protocol to receive network information through a network; and   using, by the virtualization subsystem, the network information to determine the database update.   
     
     
         19 . The method of  claim 15 , wherein the physical line card database includes a layer 2 forwarding table. 
     
     
         20 . The method of  claim 15 , wherein the physical line card database includes a layer 3 forwarding table.