Fat tree adaptive routing

1. A method, comprising:

receiving, by a switch in a network, a data flow comprising a plurality of packets at an edge port of the switch, the network comprising a plurality of switches configured in a fat-tree topology;

applying a translation rule to a respective packet of the data flow to determine a first value and a second value associated with forwarding of the packet;

applying a destination-based hash function on a set of header fields of the packet to determine a hash value comprising a predetermined number of bits;

determining a subset of the bits of the hash value based on the second value; and

determining an egress port for the packet based on the first value and the subset of the bits of the hash value.

2. The method of claim 1 , wherein the set of header fields of the packet comprises at least one of: a source address and a destination address of the packet.

3. The method of claim 1 , further comprising determining a combination of the set of header fields for the hash function based on a configuration.

4. The method of claim 1 , wherein the hash value is generated based on a combination of one or more media access control (MAC) addresses, one or more Internet Protocol (IP) addresses, and one or more port addresses of the packet.

5. The method of claim 4 , wherein applying the hash function further comprises using a Cyclic Redundancy Check (CRC) function to compress the one or more MAC addresses, one or more IP addresses, and one or more port addresses of the packet into the hash value.

6. The method of claim 1 , further comprising multiplying the hash value by the second value to determine the subset of the bits of the hash value.

7. The method of claim 6 , further comprising adding a value indicated by the subset of the bits of the hash value to the first value to form an index into an entry of a routing table indicating the egress port.

8. A switch, comprising:

a processor;

an input port to receive a data flow comprising a plurality of packets via a network configured in a fat-tree topology;

a plurality of output ports;

a non-transitory computer-readable storage medium storing instructions that when executed by the processor cause the switch to:

apply a translation rule to a respective packet of the data flow to determine a first value and a second value associated with forwarding of the packet;

apply a destination-based hash function on a set of header fields of the packet to determine a hash value comprising a predetermined number of bits;

determine a subset of the bits of the hash value based on the second value; and

determine an output port for the packet from the plurality of output ports based on the first value and the subset of the bits of the hash value; and

a crossbar switch, which couples the input port to the plurality of output ports, to route the packet to the output port.

9. The switch of claim 8 , wherein the set of header fields of the packet comprises at least one of: a source address and a destination address of the packet.

10. The switch of claim 8 , wherein a combination of the set of header fields for the hash function is determined based on a configuration.

11. The switch of claim 8 , wherein the hash value is generated based on a combination of one or more media access control (MAC) addresses, one or more Internet Protocol (IP) addresses, and one or more port addresses of the packet.

12. The switch of claim 11 , wherein applying the hash function further comprises using a Cyclic Redundancy Check (CRC) function to compress the one or more MAC addresses, one or more IP addresses, and one or more port addresses of the packet into the hash value.

13. The switch of claim 8 , wherein the instructions that when executed by the processor cause the switch to multiply the hash value by the second value to determine the subset of the bits of the hash value.

14. The switch of claim 13 , wherein the instructions that when executed by the processor cause the switch to add a value indicated by the subset of the bits of the hash value to the first value to form an index into an entry of a routing table indicating the egress port.

15. A non-transitory computer-readable storage medium storing instructions that when executed by a processor of a switch of a network cause the processor to perform a method, the method comprising:

receiving a data flow comprising a plurality of packets at an edge port of the switch, the network comprising a plurality of switches configured in a fat-tree topology;

applying a translation rule to a respective packet of the data flow to determine a first value and a second value associated with forwarding of the packet;

applying a destination-based hash function on a set of header fields of the packet to determine a hash value comprising a predetermined number of bits;

determining a subset of the bits of the hash value based on the second value; and

determining an egress port for the packet based on the first value and the subset of the bits of the hash value.

16. The non-transitory computer-readable storage medium of claim 15 , wherein the method further comprises determining a combination of the set of header fields for the hash function based on a configuration.

17. The non-transitory computer-readable storage medium of claim 15 , wherein the hash value is generated based on a combination of one or more media access control (MAC) addresses, one or more Internet Protocol (IP) addresses, and one or more port addresses of the packet.

18. The non-transitory computer-readable storage medium of claim 17 , wherein applying the hash function further comprises using a Cyclic Redundancy Check (CRC) function to compress the one or more MAC addresses, one or more IP addresses, and one or more port addresses of the packet into the hash value.

19. The non-transitory computer-readable storage medium of claim 15 , wherein the method further comprises multiplying the hash value by the second value to determine the subset of the bits of the hash value.

20. The non-transitory computer-readable storage medium of claim 19 , wherein the method further comprises adding a value indicated by the subset of the bits of the hash value to the first value to form an index into an entry of a routing table indicating the egress port.