INTERNET PROTOCOL SWITCH AND USE OF THE SWITCH FOR SWITCHING A FRAME

• US 20080247395A1
• Filed: 03/28/2008
• Published: 10/09/2008
• Est. Priority Date: 04/06/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hazard, Ludovic
• Granted Patent: US 8,135,013 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/54 Organization of routing tables

Abstract

Internet Protocol (IP) switch and method for switching an IP frame to an IP destination address. The IP switch includes access ports, interswitch ports, and a switching table. Each access port is connected to a corresponding host in a LAN. The interswitch ports are configured to be statically connected to routers within the Internet in connections that cannot be overwritten by dynamic learning. The switching table includes entries, each entry having an IP address, a port identifier, and a routing protocol internal metric indicative of confidence in the entry. The method for switching the IP frame includes: receiving the IP frame, reading the IP destination address from the IP frame, ascertaining a matching IP address in the switching table that matches the IP destination address, directing the IP frame to a specific port, transmitting the IP frame from the specific port to the IP destination address.

Claims

1. An Internet Protocol (IP) switch for switching an incoming IP frame to an IP destination address included in the IP frame, said IP switch comprising:

multiple ports comprising a plurality of access ports and a plurality of interswitch ports, wherein each access port is identified by a port identifier and is directly connected to a corresponding host in a Local Area Network (LAN), and wherein the interswitch ports are configured to be statically connected to routers within the Internet to connect the routers together in connections that cannot be overwritten by a dynamic learning process; and

a switching table comprising at least one entry, wherein each entry of the at least one entry comprises an IP address, a port identifier associated with the IP address and identifying a port of the multiple ports, and a routing protocol internal metric indicative of confidence in the entry, wherein the IP switch does not comprise a Media Access Control (MAC) table that associates a MAC address of each host in the LAN with each host'"'"'s associated port identifier.

2. The IP switch of claim 1, wherein the IP switch further comprises:

an IP address reader configured to read the IP destination address from the IP frame;

a comparator configured to make a comparison between the IP destination address included in the IP frame with the IP addresses in the at least one entry of the switching table and to determine, from said comparison, a matching IP address in the at least one entry of the switching table that matches the IP destination address included in the IP frame;

a port director configured to direct the IP frame to a specific port of the multiple ports, wherein the specific port has a port identifier in a specific entry of the at least one entry of the switching table such that the specific entry comprises the matching IP address; and

means for transmitting the IP frame from the specific port to the IP destination address.

3. The IP switch of claim 1, wherein each entry in the switching table further comprises a routing protocol internal metric indicative of confidence in the entry.

4. The IP switch of claim 3, wherein the routing protocol internal metric indicative of confidence in the entry is an administrative distance for the entry.

5. The IP switch of claim 4, wherein the at least one entry in the switching table comprises a plurality of entries, wherein each entry of at least two entries of the plurality of entries comprises the IP destination address, and wherein the IP switch further comprises means for selecting a port in the switching table that corresponds the entry of the at least two entries having the lowest administrative distance.

6. The IP switch of claim 1, wherein the IP switch further comprises a lifetime for each entry of the at least one entry of the switching table.

7. The IP switch of claim 1, wherein the IP switch further comprises a validator configured to validate the IP frame through use of a cyclic redundancy check (CRC) of the IP frame.

8. The IP switch of claim 1, wherein the IP frame includes an IP source address comprising an address of a source from which the IP frame originated.

9. The IP switch of claim 8, wherein the IP frame does not include a MAC source address corresponding to the IP source address, a MAC destination address corresponding to the IP destination address, and a frame type identifier that identifies the IP frame, and wherein the IP switch is not configured to process said MAC source address, said MAC destination address, and said frame type identifier.

10. The IP switch of claim 1, wherein a packet payload in the IP frame is unfragmented and comprises more bytes of payload data than is permitted for a packet payload in an Ethernet frame.

11. A method for switching an incoming Internet Protocol (IP) frame to an IP destination address included in the IP frame through use of an IP switch, said method comprising:

receiving the incoming IP frame at a port of multiple ports of the IP switch, wherein the IP switch comprises the multiple ports, the switching table which comprises at least one entry, and a lifetime for each entry of the at least one entry, wherein the multiple ports comprise a plurality of access ports and a plurality of interswitch ports, wherein each access port is identified by a port identifier and is connected to a corresponding host in a Local Area Network (LAN), wherein the interswitch ports are configured to be statically connected to routers within the Internet to connect the routers together in connections that cannot be overwritten by a dynamic learning process, wherein each entry of the at least one entry comprises an IP address, a port identifier associated with the IP address and identifying a port of the multiple ports, and a routing protocol internal metric indicative of confidence in the entry, and wherein the IP switch does not comprise a Media Access Control (MAC) table that associates a MAC address of each host in the LAN with each host'"'"'s associated port identifier;

after said receiving the incoming IP frame, said IP switch reading the IP destination address from the IP frame;

after said reading, said IP switch making a comparison between the IP destination address with the IP addresses in the at least one entry of the switching table;

said IP switch ascertaining, from said comparison, a matching IP address in the at least one entry of the switching table that matches the IP destination address included in the IP frame;

after said ascertaining, said IP switch directing the IP frame to a specific port of the multiple ports, wherein the specific port has a port identifier in a specific entry of the at least one entry of the switching table such that the specific entry comprises the matching IP address; and

after said directing, said IP switch transmitting the IP frame from the specific port to the IP destination address.

12. The method of claim 11, wherein said receiving comprises receiving the incoming IP frame at an access port of the plurality of access ports, and wherein the specific port is an interswitch port of the plurality of interswitch ports.

13. The method of claim 11, wherein said receiving comprises receiving the incoming IP frame at an interswitch port of the plurality of interswitch ports, and wherein the specific port is an access port of the plurality of access ports.

14. The method of claim 11, wherein the method further comprises:

after said receiving the incoming IP frame and before said reading, validating the received IP frame, wherein said validating comprises performing a cyclic redundancy check (CRC) of the IP frame.

15. The method of claim 11, wherein each entry in the switching table further comprises a routing protocol internal metric indicative of confidence in the entry.

16. The method of claim 15, wherein the routing protocol internal metric indicative of confidence in the entry is an administrative distance for the entry.

17. The method of claim 16, wherein the at least one entry in the switching table comprises a plurality of entries, wherein each entry of at least two entries of the plurality of entries comprises the IP destination address, and wherein the method further comprises:

prior to said directing the IP frame, said IP switch determining the specific port by selecting a port in an entry of the at least two entries having the lowest administrative distance.

18. The method of claim 11, wherein the LAN does not include a LAN switch comprising said MAC table.

19. The method of claim 11, wherein the IP frame further includes an IP source address comprising an address of a source from which the IP frame originated wherein the IP frame does not include a MAC source address corresponding to the IP source address, a MAC destination address corresponding to the IP destination address, and a frame type identifier that identifies the IP frame, and wherein said method does not comprise processing said MAC source address, processing said MAC destination address, and processing said frame type identifier.

20. The method of claim 11, wherein a packet payload in the IP frame is unfragmented and comprises more bytes of payload data than is permitted for a packet payload in an Ethernet frame.

21. A computer program product comprising a storage medium having computer readable program code stored therein, said program code configured to be executed by a computer to cause the computer to perform a method for for switching an incoming Internet Protocol (IP) frame to an IP destination address included in the IP frame through use of an IP switch, said method comprising:

receiving the incoming IP frame at a port of multiple ports of the IP switch, wherein the IP switch comprises the multiple ports, the switching table which comprises at least one entry, and a lifetime for each entry of the at least one entry, wherein the multiple ports comprise a plurality of access ports and a plurality of interswitch ports, wherein each access port is identified by a port identifier and is connected to a corresponding host in a Local Area Network (LAN), wherein the interswitch ports are configured to be statically connected to routers within the Internet to connect the routers together in connections that cannot be overwritten by a dynamic learning process, wherein each entry of the at least one entry comprises an IP address, a port identifier associated with the IP address and identifying a port of the multiple ports, and a routing protocol internal metric indicative of confidence in the entry, and wherein the IP switch does not comprise a Media Access Control (MAC) table that associates a MAC address of each host in the LAN with each host'"'"'s associated port identifier;

after said receiving the incoming IP frame, said IP switch reading the IP destination address from the IP frame;

after said reading, said IP switch making a comparison between the IP destination address with the IP addresses in the at least one entry of the switching table;

said IP switch ascertaining, from said comparison, a matching IP address in the at least one entry of the switching table that matches the IP destination address included in the IP frame;

after said ascertaining, said IP switch directing the IP frame to a specific port of the multiple ports, wherein the specific port has a port identifier in a specific entry of the at least one entry of the switching table such that the specific entry comprises the matching IP address; and

after said directing, said IP switch transmitting the IP frame from the specific port to the IP destination address.

22. The computer program product of claim 21, wherein said receiving comprises receiving the incoming IP frame at an access port of the plurality of access ports, and wherein the specific port is an interswitch port of the plurality of interswitch ports.

23. The computer program product of claim 21, wherein said receiving comprises receiving the incoming IP frame at an interswitch port of the plurality of interswitch ports, and wherein the specific port is an access port of the plurality of access ports.

24. The computer program product of claim 21, wherein each entry in the switching table further comprises a routing protocol internal metric indicative of confidence in the entry, and wherein the routing protocol internal metric indicative of confidence in the entry is an administrative distance for the entry.

25. The computer program product of claim 24, wherein the at least one entry in the switching table comprises a plurality of entries, wherein each entry of at least two entries of the plurality of entries comprises the IP destination address, and wherein the method further comprises:

prior to said directing the IP frame, said IP switch determining the specific port by selecting a port in an entry of the at least two entries having the lowest administrative distance.