JPS6366103B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a method for easily protecting network information in a network system in which each node has network information as a basis for determining a communication route. This invention relates to a method for detecting contradictions in network information.

[Prior art and problems]

FIG. 1 shows an overview of the network system, and A to E indicate nodes. The nodes are connected by transmission lines. When communicating, each node selects the shortest route (the route with the least communication time) based on network information, and performs communication. Now, when node A sends data to node C, node A sends the data to node B and requests relaying, and node B sends the received data to node C. Now node B
Assume that a failure occurs between node A and node C, node A is unaware of the occurrence of this failure, and node B is aware of this failure. Note that transmission path failure information is also an element of network information. Under such a state, if a transmission request to node C is generated from node A, node A transmits data to node B and requests relaying. Node B is
Since the communication path for sending data to node C is considered to be from node A→E→D→C, the received data is sent back to node A. In this way, if the network information held by each node A, B, C, D, and E is inconsistent, a loop may occur. Therefore, when network information changes, it is necessary to notify other nodes;
Communication for transmitting this to other nodes had to be synchronized with other communications, and it was also necessary to perform recovery in the event of a failure.

[Purpose of the invention]

The present invention is based on the above consideration, and an object of the present invention is to provide a method for detecting contradictions in network information that allows contradictions in network information to be easily detected during normal communication processing.

[Structure of the invention]

Therefore, the network information contradiction detection method of the present invention includes a plurality of nodes having network information tables that store network information for determining communication routes, and a transmission path connecting the nodes. A method for detecting contradictions in network information in a network system,
Each node refers to the above network information table and creates a shortest communication path table showing the shortest distance between nodes and the direct destination node, and when transmitting data to another node, Refer to the route table to find the shortest distance and direct destination node, add the shortest distance to the sending data, add the name of the other node mentioned above as the final destination node name, send directly to the destination node, and receive the data. Sometimes, it checks whether or not it is the final destination, and if it is not the final destination, it refers to the shortest communication route table above to find the distance from its own node to the final destination node, and adds that distance to the received data. The present invention is characterized in that it is configured to compare the distances between the two networks, and if the former is greater than the latter, it is recognized that there is a contradiction in network information.

[Embodiments of the invention]

Hereinafter, the present invention will be explained with reference to the drawings.

Figure 2 is a diagram showing an example of the hardware configuration of a network system to which the present invention is applied;
Figure 4 shows an example of the network information table used in the present invention, Figure 4 shows an example of the shortest communication route table, Figure 5 shows the reception processing of the host computer, and Figure 6. FIG. 2 is a diagram showing transmission processing of a host computer.

The present invention can be summarized as follows. For each of all nodes, the distance between two nodes is determined from the network information. What is distance?
This is a logical concept determined by the number of relay nodes, communication capacity, etc. It is determined that the communication route with the shortest distance (minimum time) is selected. When node B is requested to relay from node A to node C, it can detect inconsistencies in network information by performing the following checks.

Distance from B to C < Distance from A to C If this condition is not met, the network information held by node A will be different from the network information held by node B. Therefore, you can use this as a trigger to check network information, etc.

FIG. 2 shows an example of the hardware configuration of a network system to which the present invention is applied. In Fig. 2, 1-A to 1-E are host computers, 2-A to 2-E are block multiplexer channels, 3-A to 3-E are interface adapters, and 4 is a ring-shaped transmission path. are shown respectively. A host computer, block multiplexer channel, adapter, etc. constitute one node. Communication between adjacent host computers is done using CTC (Channel to channel).
This is done in a similar way to traditional channel-to-channel communication using an adapter. All communications are managed by the host computer.

FIG. 3 shows an example of a network information table. In the figure, a mark ◯ indicates that the nodes are directly connected via a transmission path, and a mark x indicates that the nodes are not directly connected. By looking at FIG. 3, for example, node A and node B,
It can be seen that node A and node E are connected. When it is determined that a failure has occurred in the transmission path between node B and node C, the circle mark in the second row and third column is changed to an x mark. The network information table shown in FIG. 3 is provided in the memory of each host computer.

FIG. 4 shows an example of the shortest communication route table. Each host computer creates a shortest communication path table based on its own network information table. In the illustrated shortest communication route table, when sending data from node A to node B, the final destination, the distance is "1" and the direct destination is node B, and when sending data from node A to node C, the final destination. Indicates that the distance is "2" and the direct destination is node B, and when sending data from node B to the final destination node C, the distance is "1" and the direct destination is node B. There is. In this example, it is assumed that the distance is determined by the number of relay nodes existing between the data transmission node and the final destination node.

FIG. 5 and FIG. 6 show the transmission and reception processing in the host computer. When communicating, a node adds a header to data and handles it as one communication block. The header contains the final destination node name, distance, etc.

FIG. 5 explains the reception processing of the host computer. When the host computer receives a communication block, it examines the header and takes it in if it is addressed to itself. If the communication block is not addressed to itself, the host computer refers to the shortest communication route table to find the shortest distance from its own node to the final destination node, and calculates the shortest distance and header from its own node to the final destination node. If the former is smaller than the latter, relay processing is performed as OK; otherwise, NG (no good) is determined and processing is performed to confirm network information.

FIG. 6 explains the transmission processing of the host computer. When a transmission request is received, the host computer refers to the shortest communication route table to find the distance and direct destination from its own node to the final destination node, creates a header containing the final destination name and distance, and sends the header and transmission data. The communication block consisting of the block and the direct destination node name are stored in memory and the block multiplexer channel is notified of the request to send. Upon receiving this notification, the block multiplexer channel takes action to send the communication block to the designated direct destination node. Similar processing is performed when transmitting data for relay. Naturally, the final destination node name should not be changed.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, inconsistencies in network information can be detected during normal communication processing.

[Brief explanation of drawings]

Figure 1 shows an overview of the network system, and Figure 2 shows the network system to which the present invention is applied.
A diagram showing an example of the hardware configuration of the system, FIG. 3 is a diagram showing an example of a network information table used in the present invention, FIG. 4 is a diagram showing an example of a shortest communication route table, and FIG. The figure shows the reception process of the host computer, and FIG. 6 shows the transmission process of the host computer. A to E...node, 1-A to 1-E...
...Host computer, 2-A to 2-E...Block multiplexer channel, 3-A to 3
-E...Interface adapter, 4...Ring-shaped transmission line.

Claims (1)

[Claims] 1. A method for detecting inconsistencies in network information in a network system comprising a plurality of nodes having network information tables that store network information for determining communication routes, and transmission paths connecting the nodes. So, each node is
Refer to the above network information table to create a shortest communication route table that shows the shortest distance between nodes and the direct destination node, and when transmitting data to another node, refer to the above shortest communication route table. Find the shortest distance and direct destination node, add the shortest distance to the sending data, add the name of the other node mentioned above as the final destination node name, send it directly to the destination node, and when the data is received, set yourself as the final destination. If you are not the final destination, find the distance from your own node to the final destination node by referring to the shortest communication route table above, and compare that distance with the distance added to the received data. 1. A method for detecting network information in advance, characterized in that the network information is compared, and if the former is larger than the latter, it is recognized that there is a contradiction in the network information.