Method and apparatus for multiple contexts and layer 3 virtual private networks

Abstract

A method an apparatus for multiple contexts and layer 3 virtual private networks is described. A method comprises providing a layer 3 virtual private network (VPN) to a first customer; providing backbone access to a second customer; and maintaining on a single network element a first set of information for the first customer separately from a second set of information for the second customer.

1 . A network element comprising: 
 a control card to host an exterior gateway protocol (EGP) process and an interior gateway protocol (IGP) process;    a machine readable medium coupled with the control card, the machine readable medium having a set of instructions to 
 cause the network element to maintain a first set of information for a first layer  3  virtual private network (VPN) and separately maintain a second set of information for a second layer  3  VPN,  
 to maintain a single exterior gateway protocol (EGP) table for the first layer  3  VPN and the second layer  3  VPN,  
 to identify the first layer  3  VPN with a first value and to identify the second layer  3  VPN with a second value, and  
 to associate a first route distinguisher (RD) with the first value and a second RD with the second value;  
   a line card coupled with the control card, the first line card to process traffic for the first layer  3  VPN and the second layer  3  VPN;    a first interface coupled with the line card, the first interface to receive traffic for the first layer  3  VPN; and    a second interface coupled with the line card, the second interface to receive traffic for the second layer  3  VPN.    
     
     
         2 . The network element of  claim 1  further comprising: 
 a second line card coupled with the control card and the line card, the second line card to process traffic for the first layer  3  VPN; and    a third interface coupled with the second line card, traffic for the first layer  3  VPN to be received through the third interface.    
     
     
         3 . The network element of  claim 1  wherein 
 the set of instructions also cause the network element to maintain a data structure to performing mappings between the first value and the first RD and between the second value and the second RD.    
     
     
         4 . The network element of  claim 1  wherein 
 the set of instructions also cause the network element to maintain a third set of information for a non-VPN customer separately from the first and second sets of information, the third set of information including a third value identifying the non-VPN customer and to maintain a second EGP table for the non-VPN customer.    
     
     
         5 . A system comprising: 
 a first piece of customer equipment to transmit and receive traffic within a first layer  3  virtual private network (VPN);    a second piece of customer equipment to transmit and receive traffic within a second layer  3  VPN; and    a network element coupled with the first piece of customer equipment and the second piece of customer equipment, the network element to maintain a first set of information for the first layer  3  VPN and separately maintain a second set of information for the second layer  3  VPN, the first set of information to include a first value identifying the first layer  3  VPN and the second set of information to include a second value identifying the second layer  3  VPN, to maintain a single shared exterior gateway protocol (EGP) table for the first layer  3  VPN and the second layer  3  VPN, and to associate the first value with a first route distinguisher (RD) and the second value with a second RD.    
     
     
         6 . The system of  claim 5  wherein 
 the first and second pieces of customer equipment correspond to a single entity.    
     
     
         7 . The system of  claim 5  wherein 
 the first and second pieces of customer equipment correspond to different entities.    
     
     
         8 . The system of  claim 5  further comprising the network element to separately maintain a third set of information for a non-VPN customer and to maintain a second EGP table for the non-VPN customer.  
     
     
         9 . The system of  claim 5  further comprising the network element to exchange update messages with the first and second pieces of customer equipment.  
     
     
         10 . The system of  claim 5  wherein the network element also maintains a data structure to perform mappings between the first value and the first RD and between the second value and the second RD.