Automatic association of local area network station addresses with a repeater port

• US 5,179,554 A
• Filed: 04/08/1991
• Issued: 01/12/1993
• Est. Priority Date: 04/08/1991
• Status: Expired due to Term

• Current Assignee: Enterasys Networks Incorporated (Extreme Networks, Inc.)
• Original Assignee: Digital Equipment Corporation (HP Inc.)
• Inventors: Lomicka, Jeffrey, Engelse, Willem
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Jung, Min
• Application Number:
  US07/682,186
• Time in Patent Office: 645 Days
• Field of Search: 370/85.13, 370/85.14, 370/92, 370/110.1, 370/97, 370/79, 370/13, 371/20.1
• US Class Current: 370/257
• CPC Class Codes: H04L 45/02 Topology update or discovery

Abstract

Automatic tracking of the topology of an extended local area network by augmenting a station address list kept by a bridge with a list of repeater numbers and repeater port numbers. The bridge periodically iterates through its list of stations to select a station address. The selected address table is forwarded to all of the repeaters connected to the bridge. The repeaters watch for the selected address appearing as a source address in a message on one of their ports. If the address is seen, they report the repeater port number back to the bridge. Because the repeaters are interconnected such that a predetermined port number is always used as the common port between repeaters, any possible ambiguities are eliminated.

Claims

1. A method for determining the location of a station with a particular segment in an extended local area network given only a selected network address, the method comprising:

forwarding the selected network address to one or more multiple-port repeaters connected to the network;

in each multiple-port repeater, comparing the selected address with the source addresses of messages incoming to the ports of the repeater; and

if the selected address matches the source address of a message, providing an indicator of the repeater port number on which the message was received, thereby identifying the selected network address with a particular segment.

2. A method as in claim 1 wherein one or more of the multiple-port repeaters are connected to a bridge, and the step of forwarding the selected network address is performed by the bridge.

3. A method as in claim 1 wherein the multiple-port repeaters are interconnected with one another such that a predetermined port number is used as the common port between repeaters.

4. A method as in claim 1 additionally comprising the steps of:

maintaining a list of network addresses for the stations connected to the network;

selecting a network address from the list of network addresses, and forwarding it to one of the repeaters;

maintaining the repeater port number indicator associated with the network address in a list; and

periodically repeating the above steps to maintain a list of repeater port numbers for each of the network addresses.

5. A method as in claim 4 wherein the step of maintaining a list of network addresses maintains a list of network addresses for the stations connected to a workgroup segment in the network.

6. A method as in claim 4 wherein one or more of the multiple-port repeaters are connected to a bridge, and the step of maintaining a list of the network addresses is performed by the bridge.

7. A method as in claim 4 wherein one or more of the multiple-port repeaters are connected to a bridge, and the steps of selecting a network address from the list of network addresses, maintaining the repeater port number indicator, and periodically repeating the above steps to maintain a list of repeater port numbers are performed by the bridge.

8. A method as in claim 4 wherein one or more of the multiple-port repeaters are connected to a bridge, and the step of maintaining the repeater port number indicator associated with the network address in a list is performed by the bridge.

9. A method as in claim 1 wherein the indicator of the repeater port number includes both a particular repeater number and a port number of a particular repeater.

10. A method for automatically tracking the topology of an extended local area network by augmenting a station address list kept by a bridge with a list of repeater numbers and repeater port numbers, comprising the steps of:

periodically iterating through the station address list to determine a selected station address;

forwarding the selected station address to one or more repeaters connected to the bridge;

in the repeaters, watching for the selected address to appear as a source address in a message on one of their ports; and

upon seeing the selected address on a port, reporting a repeater port number back to the bridge.

11. A method as in claim 10 wherein the multiple-port repeaters are interconnected with one another such that a predetermined port number is used as the common port between repeaters.

12. An apparatus for associating the location of a network station with a particular segment in an extended local area network, given only the network address of the station, the apparatus comprising:

means for forwarding the network address to one or more multiple-port repeaters connected to the network;

means for comparing the network address to the source addresses of messages incoming to the ports of the repeaters; and

means for providing an indicator of the repeater port number on which the message was received, if the means for comparing determines that the network address matches the source address of a message, and thereby for associating the network address with a particular segment.

13. An apparatus as in claim 12 wherein one or more of the multiple-port repeaters are connected to a bridge, and the means for forwarding the network address is disposed within the bridge.

14. An apparatus as in claim 12 wherein the multiple-port repeaters are interconnected with one another such that a predetermined port number is used as the common port between repeaters.

15. An apparatus as in claim 12 additionally comprising:

means for maintaining a list of network addresses for the stations connected to the network;

means for selecting a network address from the list of network addresses, and for forwarding the network address selected thereby to one of the repeaters;

means for maintaining the repeater port number indicator associated with a given network address in a list; and

means for iterating through the list of network addresses to maintain a list of repeater port numbers for each of the stations connected to the network.

16. An apparatus as in claim 15 wherein one or more of the multiple-port repeaters are connected to a bridge, and the means for maintaining a list of the network addresses is disposed within the bridge.

17. An apparatus as in claim 15 wherein the indicator of the repeater port number includes both a particular repeater number and a port number of a particular repeater.

18. An extended local area network for automatically determining the location of a network station, wherein the network includes a bridge having a workgroup port and a backbone port, and the network includes a plurality of multiple-port repeaters, the multiple-port repeaters each having a plurality of repeater ports, with at least one repeater port connected to the workgroup port of the bridge, so that at least one port of each repeater is connected in parallel with at least one port of the other repeaters and in parallel with the workgroup port of the bridge, and at least one of the remaining ports of at least one of the multiple-port repeaters is connected to a local area network segment including a plurality of network stations interconnected by a network medium, wherein

the bridge further comprises:

memory means, for storing the addresses of the stations connected to the bridge, and a repeater number and repeater port number for each station address;

means for reading a selected station address from one of the locations in the station address table memory, and for forwarding the selected station address to the multiple-port repeaters;

means for receiving a port number value and a repeater number value from one of the multiple-port repeaters in response to sending a repeater port value request control message to the repeaters;

means for storing the received port number value and repeater number in the memory means;

and wherein the multiple-port repeaters each comprise;

means for storing the selected station address;

means for comparing the selected station address to the source address portion of incoming messages received on the plurality of repeater ports, and for determining if the selected station address is equal to the source address of an incoming message;

means for determining the port number associated with the port on which the incoming message was received; and

means for forwarding the port number value to the bridge in response to receiving a port value request control message.

19. An extended local area network as in claim 18 wherein the multiple-port repeaters further comprise:

means for determining a repeater number associated with each repeater; and

means for forwarding the repeater number value to the bridge in response to receiving a port value request control message.

20. An extended local area network as in claim 18 wherein the memory means in the bridge further comprises:

a station address table memory, having a plurality of memory locations for storing the addresses of the stations connected to at least the workgroup port of the bridge;

a repeater number table memory, having a plurality of locations, with a repeater number location associated with each location in the station address table memory; and

a repeater port table memory, having a plurality of locations, with a repeater port number location associated with each location in the station address table memory.