Optimal forwarding in a network implementing a plurality of logical networking schemes

Abstract

An example method for determining an optimal forwarding path across a network having gateways configured to implement a plurality of logical networking protocols can include determining a path cost over a first logical network between each of the gateways and a source node and a path cost over the a second logical network between each of the gateways and a destination node. Additionally, the method can include determining an encapsulation cost difference between switching packets over the first and second logical networks. The method can also include determining an encapsulation overhead metric associated with one of the first or second logical networks, and weighting one of the first or second path cost by the encapsulation overhead metric. Further, the method can include selecting one of the gateways as an optimal gateway. The selection can be based on the computed path costs.

What is claimed: 
     
         1 . A method for determining an optimal forwarding path across a network, the network including a plurality of gateways configured to implement respective networking protocols for switching packets over a first logical network and a second logical network, the method comprising:
 determining a path cost over the first logical network between each of the gateways and a source node, wherein the first logical network is a Transparent Interconnect of Lots of Links (“TRILL”) fine-grained labeling (“FGL”) network;   determining a path cost over the second logical network between each of the gateways and a destination node;   determining an encapsulation cost difference between switching packets over the second logical network and switching packets over the TRILL FGL network;   determining an encapsulation overhead metric associated with switching packets over the second logical network, wherein the encapsulation overhead metric is proportional to the encapsulation cost difference;   weighting the path cost over the second logical network between each of the gateways and the destination node by the encapsulation overhead metric; and   selecting one of the gateways as an optimal gateway, wherein the selection is based on the path cost over the TRILL FGL network between each of the gateways and the source node and the weighted path cost over the second logical network between each of the gateways and the destination node.   
     
     
         2 . The method of  claim 1 , further comprising learning one or more RBridge nicknames, each RBridge nickname being uniquely associated with one of the gateways in the network, wherein learning one or more RBridge nicknames further comprises transmitting or receiving a message using a link state protocol, the message comprising at least one of an RBridge nickname and an IP address associated with one of the gateways in the network. 
     
     
         3 . The method of  claim 1 , wherein the source node comprises a physical server, and the method further comprises determining an RBridge to which the physical server is connected using a media access control (“MAC”) address table, wherein the path cost over the TRILL FGL network between each of the gateways and the source node is determined as a path cost over the TRILL FGL network between each of the gateways and the RBridge to which the physical server is connected. 
     
     
         4 . The method of  claim 1 , further comprising notifying at least one of an RBridge to which the source node is connected and an RBridge to which the destination node is connected of the optimal gateway. 
     
     
         5 . The method of  claim 4 , wherein notifying at least one of an RBridge to which the source node is connected and an RBridge to which the destination node is connected of the optimal gateway further comprises:
 encapsulating a frame with at least one of an RBridge nickname or an IP address associated with the optimal gateway; and   transmitting the encapsulated frame.   
     
     
         6 . The method of  claim 4 , wherein notifying at least one of an RBridge to which the source node is connected of the optimal gateway further comprises advertising a plurality of bindings between a MAC address associated with the destination node and RBridge nicknames and path costs associated with the gateways in the network. 
     
     
         7 . The method of  claim 4 , wherein notifying at least one of an RBridge to which the destination node is connected of the optimal gateway further comprises advertising a plurality of bindings between a MAC address associated with the source node and IP addresses and path costs associated with the gateways in the network. 
     
     
         8 . The method of  claim 1 , wherein the second logical network is a VxLAN. 
     
     
         9 . A non-transitory computer-readable recording medium having computer-executable instructions stored thereon for determining an optimal forwarding path across a network, the network including a plurality of gateways configured to implement respective networking protocols for switching packets over a first logical network and a second logical network, that, when executed by a gateway, cause the gateway to:
 determine a path cost over the first logical network between each of the gateways and a source node, wherein the first logical network is a Transparent Interconnect of Lots of Links (“TRILL”) fine-grained labeling (“FGL”) network;   determine a path cost over the second logical network between each of the gateways and a destination node;   determine an encapsulation cost difference between switching packets over the second logical network and switching packets over the TRILL FGL network;   determine an encapsulation overhead metric associated with switching packets over the second logical network, wherein the encapsulation overhead metric is proportional to the encapsulation cost difference;   weight the path cost over the second logical network between each of the gateways and the destination node by the encapsulation overhead metric; and   select one of the gateways as an optimal gateway, wherein the selection is based on the path cost over the TRILL FGL network between each of the gateways and the source node and the weighted path cost over the second logical network between each of the gateways and the destination node.   
     
     
         10 . The non-transitory computer-readable recording medium of  claim 9 , having further computer-executable instructions stored thereon that, when executed by the gateway, cause the gateway to learn one or more RBridge nicknames, each RBridge nickname being uniquely associated with one of the gateways in the network, wherein learning one or more RBridge nicknames further comprises transmitting or receiving a message using a link state protocol, the message comprising at least one of an RBridge nickname and an IP address associated with one of the gateways in the network. 
     
     
         11 . The non-transitory computer-readable recording medium of  claim 9 , wherein the source node comprises a physical server, and the non-transitory computer-readable recording medium having further computer-executable instructions stored thereon that, when executed by the gateway, cause the gateway to determine an RBridge to which the physical server is connected using a media access control (“MAC”) address table, wherein the path cost over the TRILL FGL network between each of the gateways and the source node is determined as a path cost over the TRILL FGL network between each of the gateways and the RBridge to which the physical server is connected. 
     
     
         12 . The non-transitory computer-readable recording medium of  claim 9 , having further computer-executable instructions stored thereon that, when executed by the gateway, cause the gateway to notify at least one of an RBridge to which the source node is connected and an RBridge to which the destination node is connected of the optimal gateway. 
     
     
         13 . The non-transitory computer-readable recording medium of  claim 12 , wherein notifying at least one of an RBridge to which the source node is connected and an RBridge to which the destination node is connected of the optimal gateway further comprises:
 encapsulating a frame with at least one of an RBridge nickname or an IP address associated with the optimal gateway; and   transmitting the encapsulated frame.   
     
     
         14 . The non-transitory computer-readable recording medium of  claim 12 , wherein notifying at least one of an RBridge to which the source node is connected of the optimal gateway further comprises advertising a plurality of bindings between a MAC address associated with the destination node and RBridge nicknames and path costs associated with the gateways in the network. 
     
     
         15 . The non-transitory computer-readable recording medium of  claim 12 , wherein notifying at least one of an RBridge to which the destination node is connected of the optimal gateway further comprises advertising a plurality of bindings between a MAC address associated with the source node and IP addresses and path costs associated with the gateways in the network. 
     
     
         16 . The non-transitory computer-readable recording medium of  claim 9 , wherein the second logical network is a VxLAN. 
     
     
         17 . A method for determining an optimal forwarding path across a network, the network including a plurality of gateways configured to implement respective networking protocols for switching packets over a first logical network and a second logical network, the method comprising:
 determining a path cost over the first logical network between each of the gateways and a source node;   determining a path cost over the second logical network between each of the gateways and a destination node;   determining an encapsulation cost difference between switching packets over the second logical network and switching packets over the first logical network;   determining an encapsulation overhead metric associated with switching packets over the second logical network, wherein the encapsulation overhead metric is proportional to the encapsulation cost difference;   weighting the path cost over the second logical network between each of the gateways and the destination node by the encapsulation overhead metric; and   selecting one of the gateways as an optimal gateway, wherein the selection is based on the path cost over the first logical network between each of the gateways and the source node and the weighted path cost over the second logical between each of the gateways and the destination node.   
     
     
         18 . The method of  claim 17 , wherein the first logical network is a Transparent Interconnect of Lots of Links (“TRILL”) fine-grained labeling (“FGL”) network. 
     
     
         19 . The method of  claim 18 , further comprising learning one or more RBridge nicknames, each RBridge nickname being uniquely associated with one of the gateways in the network. 
     
     
         20 . The method of  claim 17 , wherein the second logical network is a VxLAN.