Method and apparatus for enabling L3 switching by a network switch in a stacking environment

A network switch for network communications, said network switch comprising:

• a first data port interface, said first data port interface supporting at least one data port transmitting and receiving data at a first data rate;
• a second data port interface, said second data port interface supporting at least one data port transmitting and receiving data at a second data rate, different from the first data rate;
• a memory communicating with said first data port interface and said second data port interface;
• a memory management unit, said memory management unit for communicating data from said first data port interface and said second data port interface and said memory;
• and
• a communication channel, with the communication channel communicating data and messaging information between said first data port interface, said second data port interface, and said memory management unit,
• wherein said first data port interface is configured to communicate with a second switch at said first data rate and said second data port interface is configured to communicate with a third switch at said second data rate and said switch is configured to resolve a stack tag from a header of an incoming data packet and forwards the incoming data packet to one of said second and third switches based on the resolved stack tag.

A network switch in a series of network switches comprising:

• means for receiving an incoming data packet at a data port of a first switch of said series of network switches;
• means for resolving a stack tag from a header of said incoming data packet;
• means for determining whether an incoming data packet is a unicast packet, a multicast packet or an IP multicast packet;
• and to search the address resolution lookup and layer three IP lookup tables to find an egress port for said incoming data packet;
• means for forwarding said incoming data packet to at least a second switch of said series of network switches, on a stacked connection operating at a first data rate, based on the stack tag and the egress port;
• and
• means for modifying the header of said incoming packet when the egress port is one of a series of data ports of a particular switch of said series of switches.