High-availability cluster architecture and protocol

Abstract

Methods and systems are provided for an improved cluster-based network architecture. According to one embodiment, an active connection is established between a first interface of a network device and an enabled interface of a first cluster unit of a high availability (HA) cluster. The HA cluster is configured to provide connectivity between network devices of an internal and external network. A backup connection is established between a second interface of the network device and a disabled interface of a second cluster unit. While the first cluster unit is operational and has connectivity, it receives and processes all traffic originated by the network device that is destined for the external network. Upon determining the first cluster unit has failed or has lost connectivity, then all subsequent traffic originated by the network device that is destined for the external network is directed to the second cluster unit.

What is claimed is: 
     
         1 . A method comprising:
 establishing an active connection between a first interface of a network device within an internal network and an enabled interface of a first cluster unit of a high-availability (HA) cluster, wherein the HA cluster provides the internal network with connectivity to an external network;   establishing a backup connection between a second interface of the network device and a disabled interface of a second cluster unit of the HA cluster;   while the first cluster unit remains in an operational state and has connectivity to the external network, receiving and processing, by the first cluster unit via the active connection, all traffic originated by the network device that is to be transmitted onto the external network; and   upon determining the first cluster unit is in a failed state or the first cluster unit does not have connectivity to the external network, then causing all subsequent traffic originated by the network device that is to be transmitted onto the external network to be received and processed by the second cluster unit via the backup connection by enabling the disabled interface of the second cluster unit and disabling the enabled interface of the first cluster unit.   
     
     
         2 . The method of  claim 1 , further comprising:
 establishing a second active connection between a first interface of a second network device within the internal network and an enabled interface of the second cluster unit;   establishing a second backup connection between a second interface of the second network device and a disabled interface of the first cluster unit;   while the second cluster unit remains in an operational state and its link to the external network is operational, receiving and processing, by the second cluster unit via the second active connection, all traffic originated by the second network device that is to be transmitted onto the external network; and   when the second cluster unit is in a failed state or its link to the external network has failed, then causing all subsequent traffic originated by the second network device that is to be transmitted onto the external network to be received and processed by the first cluster unit via the second backup connection by enabling the disabled interface of the first cluster unit and disabling the enabled interface of the second cluster unit.   
     
     
         3 . The method of  claim 1 , wherein said first cluster unit and said second cluster unit are selected from a plurality of cluster units of the HA cluster. 
     
     
         4 . The method of  claim 1 , wherein the network device comprises a router, an access point, a hub, a switch or a client computing device. 
     
     
         5 . The method of  claim 1 , wherein said first cluster unit and said second cluster unit are connected through dual HA links 
     
     
         6 . The method of  claim 1 , further comprising electing one cluster unit from the plurality of cluster units of the HA cluster as a configuration master unit and causing configuration settings of other of the plurality of cluster units to be synchronized with configuration settings of the configuration master. 
     
     
         7 . The method of  claim 1 , further comprising synchronizing runtime information among the plurality of cluster units. 
     
     
         8 . The method of  claim 1 , wherein the enabled interface of the first cluster unit and the disabled interface of the second cluster unit share a single virtual Internet Protocol (IP) address. 
     
     
         9 . The method of  claim 1 , wherein the enabled interface of the first cluster unit and the disabled interface of the second cluster unit share a single virtual Media Access Control (MAC) address. 
     
     
         10 . A system comprising:
 a plurality of network devices coupled to an internal network; and   a plurality of cluster units configured as part of a high-availability (HA) cluster and providing the internal network with connectivity to an external network, wherein the system is configured to perform a method comprising:   establishing an active connection between a first interface of a network device of the plurality of network devices and an enabled interface of a first cluster unit of the plurality of cluster units;   establishing a backup connection between a second interface of the network device and a disabled interface of a second cluster unit of the plurality of cluster units;   while the first cluster unit remains in an operational state and has connectivity to the external network, receiving and processing, by the first cluster unit via the active connection, all traffic originated by the network device that is to be transmitted onto the external network; and   upon determining the first cluster unit is in a failed state or the first cluster unit does not have connectivity to the external network, then causing all subsequent traffic originated by the network device that is to be transmitted onto the external network to be received and processed by the second cluster unit via the backup connection by enabling the disabled interface of the second cluster unit and disabling the enabled interface of the first cluster unit.   
     
     
         11 . The system of  claim 10 , wherein the method further comprises:
 establishing an second active connection between a first interface of a second network device of the plurality of network devices and an enabled interface of the second cluster unit;   establishing a second backup connection between a second interface of the second network device and a disabled interface of the first cluster unit;   while the second cluster unit remains in an operational state and has connectivity to the external network, receiving and processing, by the second cluster unit via the second active connection, all traffic originated by the second network device that is to be transmitted onto the external network; and   upon determining the second cluster unit is in a failed state or the second cluster unit does not have connectivity to the external network, then causing all subsequent traffic originated by the second network device that is to be transmitted onto the external network to be received and processed by the first cluster unit via the second backup connection by enabling the disabled interface of the first cluster unit and disabling the enabled interface of the second cluster unit.   
     
     
         12 . The system of  claim 10 , wherein the network device comprises a router, an access point, a hub, a switch or a client computing device. 
     
     
         13 . The system of  claim 10 , wherein said first cluster unit and said second cluster unit are connected through dual HA links. 
     
     
         14 . The system of  claim 10 , wherein the method further comprises electing one cluster unit from the plurality of cluster units as a configuration master unit and causing configuration settings of other of the plurality of cluster units to be synchronized with configuration settings of the configuration master. 
     
     
         15 . The system of  claim 10 , wherein the method further comprises synchronizing runtime information among the plurality of cluster units. 
     
     
         16 . The system of  claim 10 , wherein the enabled interface of the first cluster unit and the disabled interface of the second cluster unit share a single virtual Internet Protocol (IP) address. 
     
     
         17 . The system of  claim 10 , wherein the enabled interface of the first cluster unit and the disabled interface of the second cluster unit share a single virtual Media Access Control (MAC) address.