Virtual Port Extender

1 . A system for transmitting packets, comprising:

a plurality of port extenders within a server rack configured to receive a packet from a server in the server rack;

a plurality of controlling bridges configured to transmit the packet over a network outside of the server rack; and

an overlay network configured on top of a physical network between the plurality of port extenders and the plurality of controlling bridges and configured to:

connect, using a virtual tunnel, a port extender in the plurality of port extenders to a controlling bridge in the plurality of controlling bridges, wherein the port extender and the controlling bridge do not have a direct physical connection; and

transmit, using the virtual tunnel, the packet between the port extender and the controlling bridge.

2 . The system of claim 1 , wherein to determine the virtual tunnel the port extender is further configured to:

map properties associated with the packet to determine a source virtual port of the virtual tunnel;

determine a destination virtual port associated with the controlling bridge based on the mapping to the source virtual port; and

transmit the packet to the controlling bridge through the virtual tunnel beginning at the source virtual port and ending at the destination virtual port.

3 . The system of claim 2 , wherein the port extender is further configured to:

generate a header for the packet, wherein the header identifies the address of the controlling bridge and facilitates the packet transmission over the overlay network.

4 . The system of claim 1 , wherein the overlay network uses a data link layer or a network layer to transmit the packet.

5 . The system of claim 1 , wherein the overlay network is a virtual network built on top of the physical network such that the overlay network virtually connects the port extender to the controlling bridge without a one to one connection between the port extender and the controlling bridge.

6 . The system of claim 1 , wherein the controlling bridge is further configured to:

receive the packet; and

transmit the packet over the network outside of the servers in the server rack.

7 . The system of claim 1 , wherein the controlling bridge is further configured to:

receive a second packet from the network outside of the server rack;

map properties associated with the second packet to determine a virtual port of a second port extender that is associated with a destination address of the second packet;

generate a second virtual tunnel between the controlling bridge and the second port extender based on the mapping; and

transmit the second packet to the second port extender associated with the virtual port over the second virtual tunnel in the overlay network.

8 . The system of claim 7 , wherein the properties include at least a destination Internet Protocol (IP) address of the second packet.

9 . The system of claim 7 , wherein the controlling bridge is further configured to:

generate a header for the second packet, wherein the header includes an IP address associated with the second port extender connected to a logical or physical computing device that is a destination of the second packet, and wherein the header facilitates the second packet transmission through the overlay network to the second port extender.

10 . The system of claim 7 , wherein the second port extender is further configured to:

receive the second packet using the virtual port of the port extender; and

transmit the second packet to a logical or physical computing device that is a destination or the second packet.

11 . A method of transmitting packets, comprising:

providing an overlay network for transmitting, a packet between a plurality of controlling bridges and a plurality of port extenders within a server rack, wherein a port extender connects to multiple servers in the server rack and a controlling bridge transmits the packet over a network outside of the servers in the server rack;

providing a mapping between the port extender and the controlling bridge in the plurality of controlling bridges, wherein the mapping enables the packet to travel in the overlay network between the port extender and the controlling bridge; and

transmitting the packet over the overlay network according to the mapping.

12 . The method of claim 11 , wherein providing the mapping further comprises:

receiving the packet at the port extender;

mapping properties associated with the packet to determine a source virtual port of a virtual tunnel;

selecting a destination virtual port of the virtual tunnel based on the source virtual tunnel, wherein the destination virtual port is associated with the controlling bridge; and

wherein the transmitting further comprises transmitting the packet from the port extender to the controlling bridge using the virtual tunnel in the overlay network.

13 . The method of claim 12 , further comprising:

generating a header for the packet, wherein the header includes the address of the controlling bridge and facilitates the packet transmission over the overlay network.

14 . The method of claim 12 , further comprising:

receiving the packet at the controlling bridge; and

transmitting the packet over the network outside of the servers in the server rack.

15 . The method of claim 11 , wherein the overlay network uses a data link layer or a network layer to transmit the packet.

16 . The method of claim 11 , wherein the overlay network is a virtual network built on top of a physical network.

17 . The method of claim 11 , further comprising:

receiving a second packet from the network outside of the server rack;

mapping properties associated with the second packet to determine a virtual port of a second port extender that is associated with a destination address of the second packet;

generating a second virtual tunnel between the controlling bridge and the second port extender based on the mapping; and

transmitting the second packet to the second port extender associated with the virtual port over the second virtual tunnel in the overlay network.

18 . The method of claim 17 , wherein the properties include at least a destination Internet Protocol (IP) address of the second packet.

19 . The method of claim 17 , further comprising:

generating a header for the second packet, wherein the header includes an Internet Protocol (IP) address associated with the second port extender connected to a logical or physical computing device that is a destination of the packet.

20 . The method of claim 17 , further comprising:

receiving the second packet using the virtual port of the port extender; and

transmitting the second packet to a logical or physical computing device that is a destination of the second packet.