System and method of updating a network element

Abstract

A method and apparatus of a device that performs a hitless update a boot image of a network element. In this embodiment, the device identifies the network element to update and determines if the network element has redundant paths. If this network element has redundant paths, the device configures the network element to drain data processing of the network element. In addition, the device updates the network element to a new boot image when the data processing of the network element is drained.

1 . (canceled) 
     
     
         2 . A non-transitory machine-readable storage medium having stored thereon executable instructions for performing a hitless update of a network element, which when executed by one or more processing units, cause the one or more processing units to:
 increase a forwarding cost, from an initial cost to an increased cost, for forwarding packets through the network element;   shut down physical interfaces of the network element at a time subsequent to increasing the forwarding cost of the network element;   update the network element;   restore the physical interfaces to a configuration prior to shutting down the physical interfaces; and   restore the forwarding cost for forwarding packets through the network element from the increased cost to the initial cost.   
     
     
         3 . The non-transitory machine-readable medium of  claim 2 , wherein the executable instructions, which when executed by the one or more processing units, further cause the one or more processing units to verify that the network element is stable subsequent to restoring the forwarding cost. 
     
     
         4 . The non-transitory machine-readable medium of  claim 2 , wherein the network element is a network element among two or more network elements, wherein increasing the forwarding cost of the network element causes packets to be forwarded via another network element among the two or more network elements. 
     
     
         5 . The non-transitory machine-readable medium of  claim 2 , wherein the forwarding cost is based on a routing metric of a routing protocol. 
     
     
         6 . The non-transitory machine-readable medium of  claim 5 , wherein the routing protocol is selected from the group consisting of Border Gateway Protocol and Open Shortest Path First. 
     
     
         7 . The non-transitory machine-readable medium of  claim 2 , wherein the forwarding cost is based on a switching metric of a switching protocol. 
     
     
         8 . The non-transitory machine-readable medium of  claim 2 , wherein increasing the forwarding cost includes increasing both a layer 3 routing cost and a layer 2 switching cost, wherein restoring the forwarding cost includes configuring both layer 3 routing to a configuration prior to increasing the layer 3 routing cost and layer 2 switching to a configuration prior to increasing the layer 2 switching cost. 
     
     
         9 . A non-transitory machine-readable storage medium having stored thereon executable instructions for performing a hitless update of a network element, which when executed by one or more processing units, cause the one or more processing units to:
 advertise an increased forwarding cost for forwarding packets through the network element that is an increase from an initial forwarding cost;   shut down physical interfaces of the network element at a time subsequent to advertising the increased forwarding cost;   update the network element;   restore the physical interfaces to a configuration prior to shutting down the physical interfaces; and   restore the forwarding cost for forwarding packets through the network element to the initial forwarding cost.   
     
     
         10 . The non-transitory machine-readable medium of  claim 9 , wherein the executable instructions, which when executed by the one or more processing units, further cause the one or more processing units to verify that the network element is stable subsequent to restoring the forwarding cost. 
     
     
         11 . The non-transitory machine-readable medium of  claim 10 , wherein the network element is a network element among two or more network elements, wherein advertising the increased forwarding cost of the network element causes packets to be forwarded via another network element among the two or more network elements. 
     
     
         12 . The non-transitory machine-readable medium of  claim 9 , wherein the forwarding cost is based on a routing metric of a routing protocol. 
     
     
         13 . The non-transitory machine-readable medium of  claim 12 , wherein the routing protocol is selected from the group consisting of Border Gateway Protocol and Open Shortest Path First. 
     
     
         14 . The non-transitory machine-readable medium of  claim 9 , wherein the forwarding cost is based on a switching metric of a switching protocol. 
     
     
         15 . The non-transitory machine-readable medium of  claim 9 , wherein the executable instructions, which when executed by the one or more processing units, further cause the one or more processing units to increase the forwarding cost by increasing both a layer 3 routing cost and a layer 2 switching cost, wherein restoring the forwarding cost includes configuring both layer 3 routing to a configuration prior to increasing the layer 3 routing cost and layer 2 switching to a configuration prior to increasing the layer 2 switching cost. 
     
     
         16 . A method in a network element, the method comprising:
 draining data processing in the network element by configuring the network element to (1) increase a forwarding cost, from an initial forwarding cost to an increased forwarding cost, for forwarding packets through the network element and then (2) shut down physical interfaces of the network element, including verifying the network element is stable after (1);   updating the network element; and   restoring data processing in the network element by successively restoring the physical interfaces to configurations prior to (2) and then restoring the forwarding cost for forwarding packets through the network element to the initial forwarding cost.   
     
     
         17 . The method of  claim 16 , wherein the network element is a network element among two or more network elements, wherein increasing the forwarding cost of the network element causes packets to be forwarded via another network element among the two or more network elements. 
     
     
         18 . The method of  claim 16 , wherein increasing the forwarding cost includes increasing a layer 3 routing cost and a layer 2 switching cost. 
     
     
         19 . The method of  claim 16 , wherein the forwarding cost is based on a routing metric of a routing protocol. 
     
     
         20 . The method of  claim 19 , wherein the routing protocol is selected from the group consisting of Border Gateway Protocol and Open Shortest Path First. 
     
     
         21 . The method of  claim 16 , wherein the forwarding cost is based on a switching metric of a switching protocol.