Patent ID: 9118607
Filing Date: 2015-08-25
Classification: H04L

Abstract:
1. A method for routing packets, the method comprising: receiving, at an interface of a first network device, a packet, wherein the packet comprises a destination Internet Protocol (IP) address; determining, using the destination IP address, a first IP address of a second network device to which the packet is to be sent, wherein the second network device is one of a plurality of network devices in a spine tier, wherein each of the plurality of network devices in the spine tier comprises a non-overlapping portion of a routing table, wherein the non-overlapping portion of the routing table on the second network device comprises a route for the packet; determining, by the first network device, a first media access control (MAC) address of the second network device using the first IP address; rewriting the packet to obtain a first rewritten packet, wherein the first rewritten packet comprises the first MAC address as a destination MAC address of the first rewritten packet and the destination IP address; sending the first rewritten packet to the second network device; performing, by the second network device using the destination IP address, a routing table lookup, wherein the routing table lookup comprises using the non-overlapping portion of the routing table on the second network device to determine a second IP address corresponding to a third network device to which the packet is to be sent; determining, by the second network device, a second MAC address of the third network device using the second IP address; rewriting the first rewritten packet to obtain a second rewritten packet, wherein the second rewritten packet comprises the second MAC address as a destination MAC address of the second rewritten packet and the destination IP address; sending the second rewritten packet to the third network device; rewriting the second rewritten packet, by the third network device using the second MAC address and an egress table, to obtain a third rewritten packet, wherein the third rewritten packet comprises a third MAC address as the destination MAC address of the third rewritten packet and the destination IP address; and sending the third rewritten packet from an interface on the third network device to an external network device, wherein the interface is associated with the third MAC address, wherein the first network device and the third network device are not in the spine tier.