Static routing system

• US 5,680,116 A
• Filed: 12/22/1994
• Issued: 10/21/1997
• Est. Priority Date: 12/27/1993
• Status: Expired due to Term

• Current Assignee: NEC Platforms, Ltd. (NEC Corporation)
• Original Assignee: NEC Corporation
• Inventors: Tamiya, Hirokazu, Hashimoto, Akira
• Primary Examiner(s): Holloway, III, Edwin C.
• Application Number:
  US08/362,244
• Time in Patent Office: 1,034 Days
• Field of Search: 340/827, 340/825.02, 340/325.08, 395/200.15, 379/220, 370/85.13, 370/248, 370/257, 370/351, 370/400, 370/401, 370/457, 370/908, 370/911
• US Class Current: 370/254
• CPC Class Codes: H04L 45/02 Topology update or discovery

Abstract

A desired static route is read from a static routing table and a polling is effected on a network connected to a terminal at regular intervals. If a normal response is issued from the network, then information about the above static route is entered in a routing table. If no normal response is delivered from the network, then the information about the static routes entered in the routing table is deleted.

Claims

1. A static routing system comprising:

a routing table operated for effecting routing to other device connected to a local-area network;

an application program for polling said local-area network;

a static routing table in which are entered static routes including an address for a network to be routed, and a time interval required to perform polling;

a timer; and

controlling means for reading a desired static route from said static routing table and starting said application program so as to poll a corresponding network each time a lapse of a predetermined time is reported from said timer, entering said static route in said routing table when a normal response is sent back from said network and deleting said static route from said routing table when the normal response is undelivered from said network.

2. The static routing system as claimed in claim 1, wherein said static route table includes an address for a network, an address for a relay node of said network and metrics counted up to said network.

3. The static routing system as claimed in claim 2, wherein said static routing table further includes ENTRY information including first information providing an indication when the static route for said network has been entered in said routing table and second information providing an indication when the static route has not been entered therein and STATE information indicative of communications states with said network, including an "Active" state showing that a normal response to an executed polling is issued and communications are satisfactory, a "Doubt" state indicative of a possibility that communications are faulty because a normal response to one polling is not being obtained and a "Stop" state showing that a failure in communications is estimated to have been produced because the normal response to the executed polling is not being continuously obtained, said ENTRY information and said STATE information being set as initial states to said second information and to said "Stop" state respectively, and said controlling means includes updating means for updating said ENTRY information and said STATE information according to the results of executed polling.