Network switching architecture with multiple table synchronization, and forwarding of both IP and IPX packets

A method of switching data in a network switch, said method comprising:

• receiving an incoming packet at a first port of a switch;
• reading a first packet portion, less than a full packet length, to determine particular packet information, said particular packet information including a source address and a destination address;
• comparing the particular packet information to information contained in a lookup table;
• if a match is made between the particular packet information and a first entry in the lookup table, modifying the packet to include appropriate forwarding and routing information thereto based on the first entry in the lookup table, and sending the packet on a communication channel to a selected memory buffer;
• if there is no match between the particular packet information and the lookup table, learning the particular packet information and placing the information as a second entry in the lookup table, and modifying the packet information to indicate that the packet is to be sent to all ports on the network switch, then sending the packet to the selected memory buffer;
• and
• retrieving the packet from the selected memory buffer, and sending the packet to appropriate destination ports as indicated in the modified packet information.

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

• a first data port interface, said first data port interface supporting a plurality of data ports transmitting and receiving data at a first data rate;
• a second data port interface, said second data port interface supporting a plurality of data ports transmitting and receiving data at a second data rate;
• a CPU interface, said CPU interface configured to communicate with a CPU;
• an internal memory, said internal memory communicating with said first data port interface and said at least one second data port interface;
• a memory management unit, said memory management unit including an external memory interface for communicating data from at least one of said first data port interface and said second data port interface and an external memory;
• a communication channel, said communication channel for communicating data and messaging information between said first data port interface, said second data port interface, said internal memory, and said memory management unit;
• protocol determining means for determining whether an incoming packet is an IP packet or an IPX packet;
• an IP router table for looking up addresses of IP packets;
• an IPX router table for looking up IPX addresses of IPX packets;
• and
• an L3 table containing a plurality of L3 addresses,
• wherein, after a determination by the protocol determining means whether the packet is an IP or an IPX packet, an appropriate lookup is performed on the L3 table and one of the IPX router table and the IPX router table, wherein a match is determined based upon a longest prefix match of the packet with an entry in the table.

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

• a first data port interface, said first data port interface supporting a plurality of data ports transmitting and receiving data at a first data rate;
• a second data port interface, said second data port interface supporting a plurality of data ports transmitting and receiving data at a second data rate;
• a CPU interface, said CPU interface configured to communicate with a CPU;
• an internal memory, said internal memory communicating with said first data port interface and said at least one second data port interface;
• a memory management unit, said memory management unit including an external memory interface for communicating data from at least one of said first data port interface and said second data port interface and an external memory;
• a communication channel, said communication channel for communicating data and messaging information between said first data port interface, said second data port interface, said internal memory, and said memory management unit;
• port movement detection means for detecting movement of a user from a first port to a second port, said port movement detecting means detecting a new port identification on a response packet coming from the user at the second port.

A method of switching packets in a network switch, said method comprising:

• receiving an incoming packet on a first data port;
• determining whether said packet is an IP packet or an IPX packet;
• performing a lookup of a L3 lookup table to determine if a match can be found with selected fields of the packet;
• if the packet is determined to be an IP packet, concurrently performing a lookup of an IP lookup table to determine if a match can be found of IP address information in the packet and corresponding IP address information in the IP lookup table;
• if the packet is determined to be an IPX packet, concurrently performing a lookup of an IPX lookup table to determine if a match can be found of IPX address information in the packet and corresponding IPX address information in the IPX lookup table;
• if a match is found during the L3 lookup, abandoning the IP and IPX lookups and forwarding the packet to an appropriate port based upon the L3 lookup;
• if there is no match on the L3 lookup, forwarding the packet to an appropriate destination based upon the match in the IP or IPX lookup;
• if there is no match in the IP or IPX lookup, forwarding the packet to the CPU interface for packet handling by the CPU.