Distributed address resolution protocol forwarding

1. A network interface within a network device, comprising:

a memory having a first table and a second table stored therein;

the first table including a first set of routing entries for correlating network addresses with physical addresses, wherein the first table is different from routing tables for correlating network addresses with physical addresses in a plurality of additional network interfaces within the network device;

the second table including a second set of routing entries for correlating each of a set of prefixes of network addresses to one of the plurality of additional network interfaces on the network device; and

a packet processor for:

receiving a packet including a destination address;

when the destination address matches a matching network address in the first set of routing entries, determining a physical address associated with the matching network address and converting the destination address to the physical address;

determining the destination address fails to match a network address in the first set of routing entries;

determining the prefix of the destination address matches at least one of the set of prefixes of network addresses in the second set of routing entries; and

determining one of the plurality of additional network interfaces within the network device associated with the prefix of the destination address and forwarding the packet to the additional network interface, wherein the additional network interface is configured with another routing table including the destination address and associated physical destination address.

2. The network interface of claim 1 , further comprising:

a central processing unit (CPU) configured for resolving unknown network addresses;

wherein the second set of routing entries in the second table correlates each of another set of prefixes of network addresses to the CPU; and

wherein the packet processor is further configured for:

determining the prefix of the destination address matches at least one of the another set of prefixes of network addresses and forwarding the packet to the CPU for resolving the unknown destination address.

3. The network interface of claim 1 , wherein the packet processor further:

compares the destination address with each of the network addresses in the first set of routing entries;

identifies the matching network address when a match is found between the destination address and one of the network addresses in the first set of routing entries; and

compares the destination address with the second set of routing entries when the destination address does not match any of the network addresses in the first set of routing entries.

4. The network interface of claim 1 , wherein the destination address is an Internet Protocol (IP) address.

5. The network interface of claim 1 , wherein the physical address is a Media Access Control (MAC) address.

6. The network interface of claim 1 , wherein the first set of routing entries are Address Resolution Protocol (ARP) entries.

7. The network interface of claim 1 , wherein the second set of routing entries are Longest Prefix Match (LPM) entries.

8. The network interface of claim 1 , further comprising:

an Application Specific Integrated Circuit (ASIC) having the memory and the packet processor.

9. A network device, comprising:

a switch fabric; and

a plurality of network interfaces coupled via the switch fabric, each of the plurality of network interfaces including:

a memory configured for storing:

a first table including a first set of routing entries for correlating network addresses with physical addresses, wherein each of the plurality of network interfaces includes a different first table that correlates a different set of network addresses with physical addresses; and

a second table including a second set of routing entries for correlating each of a set of prefixes of network addresses to one of the plurality of network interfaces, wherein each prefix corresponds to a range of network addresses in one of the different sets of network addresses in one of the different first tables of the plurality of network interfaces; and

a packet processor for:

receiving a packet including a destination address;

when the destination address matches a matching network address in the first set of routing entries, determining a physical address associated with the matching network address and converting the destination address to the physical address;

comparing a prefix of the destination address to the set of prefixes of network addresses;

determining the prefix of the destination address matches at least one of the set of prefixes of network addresses in the second set of routing entries; and

determining a designated one of the plurality of network interfaces within the network device associated with the prefix of the destination address and forwarding the packet to the designated one of the plurality of network interfaces.

10. The network device of claim 9 , wherein each of the plurality of network interfaces is programmed with a distinct set of network addresses such that each of the network addresses is programmed on a single one of the plurality of network interfaces.

11. The network device of claim 10 , wherein the designated network interface has the destination address of the packet programmed thereon.

12. The network device of claim 9 , wherein each of the plurality of network interfaces further includes:

a central processing unit (CPU) for resolving unknown network addresses;

wherein the second set of routing entries further correlates unknown partial network addresses with the CPU;

wherein the packet processor further forwards the packet to the CPU when the destination address matches a matching unknown partial network address in the second set of routing entries.

13. The network device of claim 9 , wherein the packet processor further:

compares the destination address with each of the network addresses in the first set of routing entries;

identifies the matching network address when a match is found between the destination address and one of the network addresses in the first set of routing entries; and

compares the destination address with each of the partial network addresses in the second set of routing entries when the destination address does not match any of the network addresses in the first set of routing entries.

14. The network device of claim 9 , wherein the network addresses are Internet Protocol (IP) addresses.

15. The network device of claim 9 , wherein the physical addresses are Media Access Control (MAC) addresses.

16. The network device of claim 9 , wherein the first set of routing entries are Address Resolution Protocol (ARP) entries.

17. The network device of claim 9 , wherein the second set of routing entries are Longest Prefix Match (LPM) entries.

18. The network device of claim 9 , wherein each of the plurality of network interfaces includes an Application Specific Integrated Circuit (ASIC).

19. A method for distributed Address Resolution Protocol (ARP) forwarding in a network device, comprising:

receiving a packet including a destination address at a network interface of the network device;

accessing, by the network interface, a first table including a first set of routing entries for correlating network addresses with physical addresses;

when the destination address matches a matching network address in the first set of routing entries, determining a physical address associated with the matching network address and converting the destination address to the physical address;

determining that the destination address does not match any of the network addresses in the first set of routing entries and accessing, by the network interface, a second set of routing entries including a plurality of sets of prefixes of network addresses, wherein each of the plurality of sets of prefixes of network addresses is associated with one of the plurality of network interfaces; and

determining that a prefix of the destination address matches a prefix in one of the plurality of sets of prefixes of network addresses in the second set of routing entries; and

determining a designated network interface associated with the matching prefix and forwarding the packet to the associated network interface via the network fabric.

20. The method of claim 19 , wherein the second set of routing entries further correlates unknown partial network addresses with a central processing unit (CPU) in the network device, and further comprising:

forwarding the packet to the CPU when the destination address matches a matching unknown partial network address in the second set of routing entries.