A system for interconnecting a plurality of separate networks, the system comprising: a plurality of network segments located at different segmented networks , the plurality of network segments comprising at least (i) a first network segment of a first network segmented using a first technique and (ii) a second network segment of a second network segmented using a second technique; a set of interconnection forwarding elements ; characterized in that: each interconnection forwarding element has a first physical port that interfaces with a particular one of the network segments and a second physical port that interfaces with an interconnecting network to which all of the interconnection forwarding elements connect to provide connections between the plurality of network segments; and a network controller is configured to manage the set of interconnection forwarding elements by defining a logical forwarding element that connects the plurality of network segments located at different segmented networks , the logical forwarding element comprising logical ports to which each of the network segments couple, wherein the logical forwarding element is for implementation by each of the interconnection forwarding elements , with each logical port corresponding to one of the interconnection forwarding elements . a plurality of network segments located at different segmented networks , the plurality of network segments comprising at least (i) a first network segment of a first network segmented using a first technique and (ii) a second network segment of a second network segmented using a second technique; a set of interconnection forwarding elements ; characterized in that: each interconnection forwarding element has a first physical port that interfaces with a particular one of the network segments and a second physical port that interfaces with an interconnecting network to which all of the interconnection forwarding elements connect to provide connections between the plurality of network segments; and a network controller is configured to manage the set of interconnection forwarding elements by defining a logical forwarding element that connects the plurality of network segments located at different segmented networks , the logical forwarding element comprising logical ports to which each of the network segments couple, wherein the logical forwarding element is for implementation by each of the interconnection forwarding elements , with each logical port corresponding to one of the interconnection forwarding elements . each interconnection forwarding element has a first physical port that interfaces with a particular one of the network segments and a second physical port that interfaces with an interconnecting network to which all of the interconnection forwarding elements connect to provide connections between the plurality of network segments; and a network controller is configured to manage the set of interconnection forwarding elements by defining a logical forwarding element that connects the plurality of network segments located at different segmented networks , the logical forwarding element comprising logical ports to which each of the network segments couple, wherein the logical forwarding element is for implementation by each of the interconnection forwarding elements , with each logical port corresponding to one of the interconnection forwarding elements . <EOS>