초록 ▼

A method of operating a switch for frames in a computer network uses one or more indicia of frame type designation found in the received frame to derive a virtual local area network (derived VLAN) value. Also, an indicia of the receiving port may be used in constructing the derived VLAN value. The s

A method of operating a switch for frames in a computer network uses one or more indicia of frame type designation found in the received frame to derive a virtual local area network (derived VLAN) value. Also, an indicia of the receiving port may be used in constructing the derived VLAN value. The switch then uses the derived VLAN value in making forwarding decisions. Broadcast domains in the computer network may then be controlled by forwarding in response to the derived VLAN value.

대표청구항 ▼

What is claimed is: 1. A method of operating a switch for frames in a computer network, comprising: receiving a frame (received frame) at a port of said switch, said received frame containing one or more indicia of frame type, said one or more indicia of frame type including an indicia of a protoco

What is claimed is: 1. A method of operating a switch for frames in a computer network, comprising: receiving a frame (received frame) at a port of said switch, said received frame containing one or more indicia of frame type, said one or more indicia of frame type including an indicia of a protocol type; accessing a port index value associated with the port; deriving a virtual local area network (derived VLAN) value in response to said one or more indicia of frame type and said port index value; accessing a forwarding data base with said derived VLAN value to determine a destination address; and, forwarding, in response to said derived VLAN value, said received frame to an output port for transmission to the destination address. 2. The method of claim 1 wherein the step of deriving further comprises: generating a protocol code from the indicia of protocol type; combining the protocol code with the index value to produce a mapping address; and accessing a memory structure with the mapping address to obtain the derived VLAN. 3. The method of claim 1 wherein the indicia of protocol type indicates an Internet Protocol (IP) protocol type. 4. An apparatus to forward frames in a computer network, comprising: a port to receive a frame (received frame), said port associated with an index value, said received frame containing one or more indicia of frame type, said one or more indicia of frame type including an indicia of a protocol type; a parsing engine to derive a virtual local area network (derived VLAN) value in response to said one or more indicia of frame type and said index value; a forwarding database configured to use said derived VLAN value as input and to yield a destination address as output; and, an output port to transmit said received frame, in response to said derived VLAN value, to said destination address. 5. The apparatus as in claim 4 further comprising: a protocol mapping table to map the indicia of protocol type to a protocol code; and wherein the parsing engine is configured to combine the protocol code with the index value to produce a mapping address and to access a memory structure with the mapping address to obtain the derived VLAN. 6. The apparatus as in claim 4 wherein the indicia of protocol type indicates an Internet Protocol (IP) protocol type. 7. An apparatus to forward frames in a computer network, comprising: means for receiving a frame (received frame), said received frame containing one or more indicia of frame type, said one or more indicia of frame type including an indicia of a protocol type; means for accessing an index value associated with the means for receiving a frame; means for deriving a virtual local area network (derived VLAN) value in response to said one or more indicia of frame type and said index value; means for accessing a forwarding database with said derived VLAN value to de-termine a destination address; and, means for forwarding, in response to said derived VLAN value, said received frame to an output port for transmission to the destination. 8. A method of operating a switch for frames in a computer network, comprising: receiving a frame (received frame) at a port of said switch, said received frame containing one or more indicia of frame type, said one or more indicia of frame type including an indicia of a protocol type; accessing a virtual local area network (VLAN) value associated with the port; deriving a virtual local area network (derived VLAN) value for use internal to said switch by, generating a protocol code from the indicia of protocol type, combining the protocol code with the VLAN value to produce a mapping address, and accessing a memory structure with the mapping address to obtain the derived VLAN value; accessing a forwarding database with said derived VLAN value to determine a destination address; and, forwarding, in response to said derived VLAN value, said received frame to an output port for transmission to the destination address. 9. The method of claim 8 wherein said indicia of frame type further comprises: a subnet value. 10. The method of claim 8 further comprising: deriving a MAC address from said derived VLAN value and forwarding said received frame to the output port for transmission to a destination having said MAC address. 11. The method of claim 8 wherein the indicia of protocol type indicates an Internet Protocol (IP) protocol type. 12. An apparatus to forward frames in a computer network, comprising: a port to receive a frame (received frame), said port associated with a virtual local area network (VLAN) value, said received frame containing one or more indicia of frame type, said one or more indicia of frame type including an indicia of a protocol type; a protocol mapping table to map the indicia of protocol type to a protocol code; a parsing engine to derive a virtual local area network (derived VLAN) value, wherein the parsing engine is configured to combine the protocol code with the VLAN value to produce a mapping address and to access a memory structure with the mapping address to obtain the derived VLAN; a forwarding database configured to use said derived VLAN value as an input and to yield a destination address as an output; and an output port to transmit said received frame, in response to said derived VLAN value, to said destination address. 13. The apparatus as in claim 12 further comprising: a forwarding engine for forwarding said received frame in response to said derived VLAN value and said destination address. 14. The apparatus as in claim 12 wherein the indicia of protocol type indicates an Internet Protocol (IP) protocol type. 15. A method comprising: receiving a frame at a input port, the frame including a protocol type; accessing a virtual local area network (VLAN) value associated with the input port; associating the frame with a protocol code based on the frame's protocol type; concatenating the protocol code together with the VLAN value to produce a mapping address; applying the mapping address to a memory structure to obtain a derived VLAN value that is based upon both the frame's protocol type and the VLAN value associated with the input port, the derived VLAN value to differ from at least one other derived VLAN value for another frame received on the input port, but having a different protocol type; accessing a forwarding database with the derived VLAN value to determine a destination address; and forwarding the frame to an output port for transmission to the destination address. 16. The method of claim 15 wherein the step of associating further comprises: mapping the protocol type to a protocol code using a protocol mapping table. 17. The method of claim 15 wherein the frame includes the protocol type in a protocol type field. 18. The method of claim 15 wherein the protocol type indicates Internet Packet Exchange (IPX) protocol. 19. An apparatus comprising: an input port to receive a frame, the frame including a protocol type, the input port associated with a virtual local area network (VLAN) value; a protocol mapping table to map the frame's protocol type to a protocol code; an engine to concatenate the protocol code together with the VLAN value to produce a mapping address, and to apply the mapping address to a memory structure to obtain a derived VLAN value that is based upon both the frame's protocol type and VLAN value associated with the input port, the derived VLAN value to differ from at least one other derived VLAN value for another frame received on the input port, but having a different protocol type; a forwarding database to use the derived VLAN value to determine a destination address; and an output port to transmit the frame to the destination address. 20. The apparatus of claim 19 wherein the frame includes the protocol type in a protocol type field. 21. The apparatus of claim 19 wherein the protocol type indicates Internet Packet Exchange (IPX) protocol. 22. A method comprising: receiving a frame at an input port, the frame including a protocol type and a source address; in response to the protocol type indicating a particular protocol type, parsing the source address to obtain a subnet value; applying the subnet value to a memory structure to map the subnet value to a derived VLAN value, the derived VLAN value to differ from at least one other derived VLAN value for another frame received on the input port, but having a different subnet value; accessing a forwarding database with the derived VLAN value to determine a destination address; and, forwarding the frame to an output port for transmission to the destination address. 23. The method of claim 22, wherein the particular protocol type is Internet Protocol (IP). 24. An apparatus comprising: an input port to receive a frame, the frame including a protocol type and a source address; an engine to, in response to the protocol type indicating a particular protocol type, parse the source address to obtain a subnet value, and to apply the subnet value to a memory structure to map the subnet value to a derived VLAN value, the derived VLAN value to differ from at least one other derived VLAN value for another frame received on the input port, but having a different subnet value; a forwarding database to use the derived VLAN value to determine a destination address; and an output port to transmit the frame to the destination address. 25. The apparatus of claim 24, wherein the particular protocol type is Internet Protocol (IP).