Supporting multiple multicast trees in trill networks

1. A switch, comprising:

determining circuitry configured to:

determine an internal multicast group identifier comprising a first and a second sets of bits, wherein the first set of bits is based on a source address and a multicast address associated with a multicast packet, wherein the second set of bits is based on:

a multicast tree identifier in response to associated with the multicast packet being associated with the multicast tree identifier; and

a hash-based technique in response to the multicast packet not being associated with a multicast tree identifier; and

wherein scope of the internal multicast group identifier is internal and local within the switch; and

forwarding circuitry configured to determine one or more output ports for the multicast packet by performing a lookup using the internal multicast group identifier.

2. The switch of claim 1 , wherein the determining circuitry is configured to:

combine the first set of bits and the second set of bits to determine the internal multicast group identifier by concatenating the first set of bits and the second set of bits.

3. The switch of claim 1 , wherein the forwarding circuitry is further configured to:

associate at least one copy of the multicast packet with a respective port in the one or more output ports.

4. The switch of claim 1 , wherein the multicast packet is a multicast TRILL (Transparent Interconnection of Lots of Links) packet.

5. The switch of claim 1 , wherein the multicast tree identifier field is a routing bridge (RBridge) nickname.

6. The switch of claim 1 , wherein the source address and the multicast address are Ethernet medium access control (MAC) addresses.

7. The switch of claim 1 , wherein the source address and the multicast address are Internet Protocol (IP) addresses.

8. A computing system, comprising:

a processor; and

a memory storing instructions that when executed by the processor cause the system to perform a method, the method comprising:

determining an internal multicast group identifier comprising a first and a second sets of bits, wherein the first set of bits is based on a source address and a multicast address associated with a multicast packet, wherein the second set of bits is based on:

a multicast tree identifier in response to associated with the multicast packet, being associated with the multicast tree identifier; and

a hash-based technique in response to the multicast packet not being associated with a multicast tree identifier; and

wherein scope of the internal multicast group identifier is internal and local within the system; and

determining one or more output ports for the multicast packet by performing a lookup using the internal multicast group identifier.

9. The computing system of claim 8 , wherein the method further comprising:

combining the first set of bits and the second set of bits by concatenating the first set of bits and the second set of bits.

10. The computing system of claim 8 , wherein the method further comprises:

associating at least one copy of the multicast packet with a respective port in the one or more output ports.

11. The computing system of claim 8 , wherein the multicast packet is a multicast TRILL (Transparent Interconnection of Lots of Links) packet.

12. The computing system of claim 8 , wherein the multicast tree identifier field is a routing bridge (RBridge) nickname.

13. The computing system of claim 8 , wherein the source address and the multicast address are Ethernet medium access control (MAC) addresses.

14. The computing system of claim 8 , wherein the source address and the multicast address are Internet Protocol (IP) addresses.

15. A method, comprising:

determining an internal multicast group identifier comprising a first and a second sets of bits, wherein the first set of bits is based on a source address and a multicast address associated with a multicast packet, wherein the second set of bits is based on:

a multicast tree identifier in response to associated with the multicast packet, being associated with the multicast tree identifier; and

a hash-based technique in response to the multicast packet not being associated with a multicast tree identifier; and

wherein scope of the internal multicast group identifier is internal and local within a switch; and

determining one or more output ports for the multicast packet by performing a lookup using the internal multicast group identifier.

16. The method of claim 15 , further comprising:

combining the first set of bits and the second set of bits by concatenating the first set of bits and the second set of bits.

17. The method of claim 15 , further comprising:

associating at least one copy of the multicast packet with a respective port in the one or more output ports.

18. The method of claim 15 , wherein the multicast packet is a multicast TRILL (Transparent Interconnection of Lots of Links) packet.

19. The method of claim 15 , wherein the multicast tree identifier field is a routing bridge (RBridge) nickname.

20. The method of claim 15 , wherein the source address and the multicast address are Ethernet medium access control (MAC) addresses.

21. The method of claim 15 , wherein the source address and the multicast address are Internet Protocol (IP) addresses.