Method for configuring distributed internet protocol gateways with lan emulation

• US 6,091,732 A
• Filed: 11/20/1997
• Issued: 07/18/2000
• Est. Priority Date: 11/20/1997
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Systems, Inc.
• Inventors: Lloyd, John, Alexander, Cedell Adam Jr., Ervin, Jimmy Philip, Vig, Deepak, Matlack, Richard Colbert Jr.
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Pham, Brenda H.
• Application Number:
  US08/975,481
• Time in Patent Office: 971 Days
• Field of Search: 370/389, 370/401, 370/410, 709/202, 709/203, 709/204, 709/227, 709/245, 709/225
• US Class Current: 370/401
• CPC Class Codes: H04L 12/4608 LAN interconnection over ATM networks

Abstract

A communication network having a plurality of routers, each connected to a host system by a LAN network and interconnected by a switched network, the common network using a shared or common IP and MAC address in the routers forming a subnet. Host systems on the same subnet use the shared or common IP address as their default gateway address when accessing host systems on another subnet.

Claims

1. A method for configuring a communication network having:

i) a plurality of network switches, at least some of the network switches having routing capabilities, each network routing switch further having a unique internet protocol (IP) address, ii) a plurality of local area networks (LANs), each LAN having at least one communicating device with a unique IP address, each LAN further connected to a corresponding network routing switch, and iii) a switched network connected to the plurality of network routing switches, said method comprising the steps of;

defining a first subnet, said first subnet comprising a set of selected network routing switches and a set of selected communication devices;

assigning a common IP address and a common medium access control (MAC) address to each of the network routing switches in said set of selected network routing switches; and

assigning said common IP address as a gateway address to each of the communication devices in said set of selected communication devices.

2. The method of claim 1 further comprising the step of configuring of the network routing switches in said set of selected network routing switches to ignore address resolution protocols directed to said common IP address from the communications network.

3. The method of claim 1 further comprising the step of configuring each of the network routing switches in said set of selected network routing switches to respond to said common IP address only when received from a LAN connected to another network switch in said set of selected network routing switches.

4. The method of claim 1 further comprising the steps of:

defining a second subnet, said second subnet comprising a second set of selected network routing switches and a second set of selected communication devices;

assigning a second common IP address and a second common MAC address to each of the network routing switches in said second set of selected network routing switches; and

assigning said second common IP address as a gateway address to each of the communication devices in said second set of selected communication devices.

5. The method of claim 4 further comprising the step of configuring each of the network routing switches in said second set of selected network routing switches to ignore address resolution protocols directed to said second common IP address from the communications network.

6. The method of claim 4 further comprising the step of configuring each of the network routing switches in said second set of selected network routing switches to respond to said second common IP address only when received from a LAN connected to another routing switch in said second set of selected network routing switches.

7. A method for configuring a communication network having:

i) a plurality of network switches, at least some of the network switches having routing capabilities, each network routing switch further having a unique internet protocol (IP) address, ii) a plurality of local area networks (LANs), each LAN having at least one communicating device with a unique IP address, each LAN further connected to a corresponding network switch, iii) a central router having a unique IP address, and iv) a switched network connected to the central router and to the plurality of network routing switches, said method comprising the steps of;

defining a first subnet, said first subnet comprising the central router, a set of selected network routing switches, and a set of selected communication devices;

assigning a common IP address and a common medium access control (MAC) address to the central router;

assigning said common IP address and said common MAC address to each of the network routing switches in said set of selected network routing switches; and

assigning said common IP address as a gateway address to each of the communication devices in said set of selected communication devices.

8. The method of claim 7 further comprising the steps of:

configuring the central router to ignore address resolution protocols directed to said common IP address from the communications network; and

configuring each of the network routing switches in said set of selected network routing switches to ignore address resolution protocols directed to said common IP address from the communications network.

9. The method of claim 7 further comprising the steps of:

configuring the central router to respond to said common IP address only when received from a LAN connected to another network routing switch in said set of selected network routing switches; and

configuring each of the network routing switches in said set of selected network routing switches to respond to said common IP address only when received from a LAN connected to another network switch in said set of selected network routing switches.

10. The method of claim 7 further comprising the steps of:

defining a second subnet, said second subnet comprising the central router, a second set of selected network routing switches, and a second set of selected communication devices;

assigning a second common IP address and a second common MAC address to the central router;

assigning said second common IP address and said second common MAC address to each of the network routing switches in said second set of selected network routing switches; and

assigning said second common IP address as a gateway address to each of the communication devices in said second set of selected communication devices.

11. The method of claim 10 further comprising the step of configuring each of the network routing switches in said second set of selected network routing switches to ignore address resolution protocols directed to said second common IP address from the communications network.

12. The method of claim 10 further comprising the step of configuring each of the network routing switches in said second set of selected network routing switches to respond to said second common IP address only when received from a LAN connected to another network routing switch in said second set of selected network routing switches.