JP4953141B2 - Path route search method and program - Google Patents

Description

  The present invention relates to a path route search method and program, and more particularly, to a path route search method and program in an L2 layer network composed of L2 switches.

  As a path route search technique in a communication network, a technique for searching a path path of an L3 layer network (Patent Document 2) and a technique for searching a path path of an MPLS network (Patent Document 3) are known. In the L3 layer network and the MPLS network, network devices (hereinafter referred to as “nodes”) have path route information. Therefore, a path route can be easily searched by acquiring the path route information from the node. However, the path route of the L2 layer network is black boxed, and the path route information cannot be acquired from the node.

  As a conventional route search technique in the L2 layer, there is known a method for searching a path route by analyzing a destination MAC address of packet header information (Patent Document 1). Since the information is retained, if the path does not flow for a long time and the path route changes due to a failure during that period, the correct path route of the L2 layer cannot be grasped. Furthermore, during route search processing, it is necessary to obtain the node filtering database from all nodes in order to resolve the destination MAC address, so if there are a large number of nodes in a large-scale network, traffic load will be applied to the network. However, in a large-scale network, there are problems such as a large number of packets and a heavy load on route search processing.

JP 2002-252625 A Japanese Patent Laid-Open No. 2002-354012 JP 2007-235897

  The problem to be solved is that if a state in which no packet is flowing continues for a long time, the correct path route of the L2 layer cannot be grasped, and in the case of a large-scale network, the load of route search processing is heavy.

  In the present invention, network configuration information is registered in advance, and it is only necessary to acquire failure information and block port information from a node at the time of path route search. Therefore, L2 layer path route search can be performed statically and lightly. The biggest feature is to carry out the processing burden.

  The route search method of the present invention is advantageous in that the route of the L2 layer can be correctly performed in a static state, and the route can be grasped quickly and accurately when the operator wants to confirm the route. This is because the route is determined by analyzing the network configuration information and the block port information of the L2 ring node instead of searching the route by analyzing the packet header as in the prior art.

  In addition, even in the case of a large-scale network, there is an advantage that the load of route search processing is small. The reason for this is not to analyze packets, but to minimize access to nodes during route search processing, and to select routes registered in advance and perform route search for specified paths. This is because the route search can be performed without depending on the scale of the network.

The block diagram which shows the structure of the server used for the path route search method of this invention. The figure which shows the example of a network to which the path route search method of this invention is applied. The figure which shows the structure of the table which the database in the server of this invention has. The figure which shows the structure of the table which the memory in the server of this invention has. The figure which shows the example of a network for demonstrating this invention concretely The figure which shows the content of the table which the database with respect to the network of FIG. 5 has The figure which shows the content of the table which the memory with respect to the network of FIG. 5 has The figure which shows the whole flow of the path route search method of this invention Flowchart showing start / end node search processing of the present invention Flowchart showing the via L2 ring search process of the present invention The flowchart which shows the L2 ring route search processing of this invention The figure which shows the transition of the content of the path | route information table in the path | route connection process of this invention

  The purpose of searching the path of the path in the L2 layer in a static state where no packets are flowing was realized with minimal access to the node.

  FIG. 1 is a schematic block diagram of an embodiment of the present invention, in which one computer device (server) 1 and a network 2 are shown, and the server 1 and the network 2 are connected by a LAN 3. Only one server 1 exists in the communication system, and is connected to any node of the network 2 so that telnet connection is possible to all nodes. The node has an L2 switch. As is well known, the L2 switch is a switch that operates in the data link layer (layer 2).

  FIG. 2 is a diagram illustrating a configuration example of the network 2. In FIG. 2, ring B, ring C, and ring D are clearly shown in a star configuration with ring A as the apex. Here, a ring refers to a network having a ring configuration. In such a network, nodes indicated by diamonds are connected in a ring shape. Such a node is called a ring constituent node. On the other hand, nodes indicated by rectangles are connected in a star shape, and such nodes are referred to as star constituent nodes.

  As shown in FIG. 1, the server 1 includes a CPU 10, a memory 12, and a database 13 (hereinafter referred to as DB). The CPU 10 uses the memory 12 by the memory access processing unit 100 and uses the DB 13 by the database access processing unit 101 to execute communication by the communication processing unit 102. For this purpose, an application 11 (hereinafter referred to as AP) including a node access program 110 and a route determination program 111 is provided.

  As shown in FIG. 4, the memory 12 includes an L2 ring status information table 120, a path information table 121, and a via L2 ring information table 122, and holds temporary information during processing by the CPU 10. L2 ring status information is information on the status (input node, output node, block, failure, etc.) of the nodes that make up the L2 ring. Each of the node ID 120-a, port number 120-b, and status information 120-c Consists of fields. The route information is information indicating a node that passes from the start node to the L2 ring and from the end node to the L2 ring, and includes the fields of the sequence number 121-a, node ID 121-b, and port number 121-c. . The route L2 ring information is information indicating the L2 ring that passes from the start node to the end node, and includes the fields of the sequence number 122-a and the L2 ring ID 122-b.

  The DB 13 stores configuration information in a node information table 130, a physical link information table 131, an L2 ring information table 132, a path information table 133, and a failure information table 134. The configuration information refers to information related to the configuration of the network 2 and includes node information, link connection information, L2 ring information, and path information.

  The node information stored in the node information table 130 is node-specific information set for each node. As shown in FIG. 3A, the node ID 130a, the IP address 130b, the login ID 130c, and the login password 130d of the node. , Node type 130e and upper node ID 130f. The node type is a distinction between a node of ring connection and a node of star connection, and the upper node ID is registered only when the node type is star.

  The physical link information stored in the physical link information table 131 is information indicating the nodes and the ports at both ends of each link for each link connecting the nodes. As shown in FIG. 3B, the link ID 131a, the from node It consists of fields of ID 131b, from port number 131c, to node ID 131d, and to port number 131e.

  The L2 ring information stored in the L2 ring information table 132 is information indicating the connection order of each node constituting the L2 ring together with the master node identifier and the upper L2 ring ID. As shown in FIG. Each field includes a ring ID 132a, an L2 ring name 132b, a node ID 132c, a port number 132d, a sequence number 132e, a master node identifier 132f, and an upper ring ID 132g. The master node identifier 132f is an identifier of a master node having a block port among the nodes in the ring configuration. The upper ring ID 132g is assigned only when an upper ring exists in the ring.

  The path information stored in the path information table 133 is information indicating the nodes at both ends of the currently set path. As shown in FIG. 3D, the path ID 133a, the path name 133b, the start node ID 133c, and the end node ID 133d. Each field.

  The DB 13 also stores failure information using the failure information table 134. The failure information is information indicating a location where a failure has occurred on the path, and includes fields of a failure ID 134a, a node ID 134b, and a port number 134-c as shown in FIG. Thus, the location of the failure is specified by the nodes and ports on both sides.

  FIG. 5 shows a specific configuration example of the network. In this network, nodes N1 to N3 in a ring configuration and nodes N4 to N6 in a star configuration are shown, and the block port location of the L2 ring is the port number 2 of the node N1. A block port refers to a port that is blocked so that packets do not flow with respect to the port of the node set as the L2 ring master node when an L2 ring configuration is established. In FIG. 5, the node N6 is shown above the node N1, but this is a drawing measure, and the node N6 is not an upper node of the node N1. The vertical relationship between the nodes is shown in FIG.

  In FIG. 5, N5 → N6 path is shown as path information, and communication is normally performed via a dotted route, but it is assumed that a failure has occurred in the N1-N2 link as failure information. . The data in the tables 130 to 134 for this network configuration example is as shown in FIG. The contents of the tables 120 to 122 stored in the memory 12 are specifically shown in FIGS. 7 and 12 in the following processing.

[Description of operation]
In the present invention, upper node information and upper L2 ring information are registered in the DB as configuration information. As for the upper node information, the node arranged as the node information above the node to be registered is registered as the configuration information. Similarly, for the upper L2 ring information, the L2 ring arranged higher than the L2 ring to be registered is registered as L2 ring information as configuration information. From this upper node information and upper L2 ring information, it is possible to determine to which node the packet is to be sent next in the route determination process. For L2 ring information, L2 ring connection information is registered in the DB, and at the time of route determination processing, it is expanded as L2 ring status information in memory based on the L2 ring information, and the route in the L2 ring is determined. use.

  The operator of the server 1 registers node information in the node information table 130 and link connection information in the physical link information table 131 as network configuration information. When the upper node ID 130f in the node information is registered, it is possible to determine the upstream node in the packet flow. Also, the L2 ring information is registered in the L2 ring information table 132. When the upper L2 ring ID 132g in the L2 ring information is registered, it becomes possible to determine the upstream node in the packet flow.

  After the setting as described above, path information specifying the start node and the end node is registered in the path information table 133, and this communication system is put into operation, connected to the terminal connected to the start node and the end node. Communication is performed with the other terminal. When a failure occurs, the operator of the server 1 registers the failure information in the failure information table 134. It is also possible to register automatically by acquiring SNMP (Simple Network Management Protocol) trap or MIB (Management Information Base).

  Then, it is possible to perform a route search statically in order to check whether the node setting is correct or to check which node is affected when a node failure occurs. The operator performs an operation (GUI) or a command operation (CUI) from the screen of the server 1, for example. Then, the route search program 111 is executed with the aid of the node access program 110.

  The route search is executed for the path registered as the path information. As shown in FIG. 8, (1) start / end node search processing, (2) via L2 ring search processing, (3) L2 ring route search processing and ( 4) The path of the path is searched based on the result of the process 4 of the path connection process. 9 is a flowchart of the start / end node search process, FIG. 10 is a flowchart of the via L2 ring search process, and FIG. 11 is a flowchart of the L2 ring path search process.

  When the network configuration shown in FIG. 5 is taken as a specific example, FIG. 7 (1) shows the contents of the L2 ring status information table 120 during normal operation, and FIG. 7 (2) shows (1) start / end node search processing and (2 ) The contents of the route information table 121 in the via L2 ring search process, FIG. 7 (3) is the contents of the via L2 ring information table 122 in (2) the via L2 ring search process, and FIG. 7 (4) is the L2 ring when a failure occurs. The contents of the status information table 120 are shown. Hereinafter, the three tables 120 to 122 stored in the memory 12 are simply referred to as a memory table 120, a memory table 121, and a memory table 122.

(1) Start / end node search processing (FIG. 9)
In this process, the path from the start node to the L2 ring and the path from the end node to the L2 ring are specified. The flowchart is shown in FIG.

  First, the path ID or path name is specified, the starting node is specified from the path information table 133, and the node type of the starting node is acquired from the node information table 130 (step A1 in FIG. 9). When the node type is “L2 star” (step A2), the upper node ID is obtained by acquiring the upper node ID from the node information table 130 (step A3), and further, the upper node and the upper node are determined by the physical link information table 131. A link between nodes is specified (step A4), and link information is stored in the memory table 121 (step A5). This link information is a node ID and a port number of a node (the node and a higher node) through which the path passes.

  The processing up to this point is for the start node N5, and the contents of the memory table 121 obtained as a result are as shown in the first and second lines of FIG. Next, the upper node (N4) is specified by the node information table 130 (step A6), and the process returns to step A1. Step A1 to step A5 are repeated for the node N4, and the contents of the memory table 121 obtained as a result are as shown in the third and fourth lines of FIG. Next, the upper node (N2) is specified by the node information table 130 (step A6), and the process returns to step A1.

  In step A1, since the node type of the node N2 is known as “L2 ring” (step A2), the link information is stored in the memory table 121 (step A5, line 5 in FIG. 7). The fifth line has the same contents as the fourth line, but this is a treatment for the case where the start node is the “L2 ring”. Then, the L2 ring is specified by the memory table 132, and the L2 ring ID (R2) is stored in the memory table 122 (see FIG. 7).

  The same process as the process for the start node is also performed for the end node. However, with regard to the processing of the terminal node, considering that a large number of star configuration nodes can be connected, a sufficiently large sequence number (97 to 99 in FIG. 7) is set, and the sequence number is assigned in descending order to the memory. Store in table 121. The result of the end node processing is shown in lines 6 to 8 in FIG.

(2) Via L2 ring search process (Figure 10)
The via L2 ring search process identifies the L2 ring through which the path from the start node to the end node passes. The L2 ring ID on the start node side stored in the memory table 122 is acquired (step B1 in FIG. 10), and the upper L2 ring ID is acquired from the L2 ring information table 132 (step B3). However, if the upper L2 ring does not exist as in the network example shown in FIG. 5 (step B2), this process ends. FIG. 2 shows an example network in which an upper L2 ring exists. The acquired upper L2 ring ID is compared with the L2 ring ID on the terminal node side stored in the memory table 122 (step B4).

  If they do not match (step B5), the upper L2 ring ID is added to the memory table 122 (step B6). Further, the link between the L2 rings is specified from the physical link information table 131 (step B7), and the link information ( The information about the nodes and interfaces that are passed through is additionally stored in the memory table 121 (step B8). Next, the same determination is continued for the upper L2 ring (step B9).

  On the other hand, if they match in step B4, the link between the L2 rings is specified from the physical link information table 131 (step B10), and the link information (routed node and interface information) is additionally stored in the memory table 121. (Step B11).

(3) L2 ring route search processing (Fig. 11)
In the L2 ring path search process, a path in the L2 ring stored in the memory table 122 is specified. First, the L2 ring ID stored in the memory table 122 is specified (step C1 in FIG. 11), and L2 ring information (node ID and port number) corresponding to this L2 ring ID is acquired from the memory table 132. The acquired L2 ring information is expanded twice in the memory table 120 as shown in FIG. 7A (step C3). At this time, a row of the node itself is provided between the input port number row and the output port number row of each node, and the status information column is left blank.

  Further, the entrance node and exit node of the ring are acquired from the memory table 121 (step C2). In the memory table 121, the entry node is a node (N2 in FIG. 6) that has a sequence number one before the largest sequence number (99 in FIG. 7), and the exit node is sufficient in the memory table 121. Is recognized as a node (N1 in FIG. 6) with the smallest sequence number (97 in FIG. 7).

  Next, the master node (N1 in FIG. 6) of this L2 ring is specified from the L2 ring information table 132, and the telnet application is used to log in to the master node (step C4). If login to the master node is not successful (step C5), a failure is marked at the master node location in the memory table 120 (step C6).

  On the other hand, if the login to the master node is successful (step C5), the master node ring status information (here, the block port) is acquired and the logout is performed (step C7). The ring status information is acquired when the master node issues an L2 ring status information display command. The ring status information is confirmed (step C8). If there is a block port (step C9), the block port location is marked on the L2 ring status information table 120 (step C10). If there is no block port, do nothing. Steps C4 to C10 are repeated as long as there are other master nodes (step C11).

  Next, the entry node and the exit node of the L2 ring acquired in step C2 are marked on the memory table 120 (step C12). Failure information is acquired from the failure information table 134, and if a failure has occurred in the L2 ring, the failure is marked at the corresponding location (step C13). In FIG. 5, a failure has occurred between the port 1 of the node N1 and the port 2 of the node N2, and at that time, the operator of the server 1 shows a failure in the failure information table 134 as shown in FIG. Information is registered. When a failure occurs, the block port is automatically opened.

  Next, the memory table 120 is searched in order, and a path without a block port or fault marking is confirmed between the entry node and the exit node (step C14). As a result, if there is such a route (step C15), the information of the node and interface through which the route passes is stored in the memory table 121, and the memory table 120 is cleared (step C16).

  In FIG. 7 (4), the route from the port 1 of the node N2 to the port 2 of the node N1 via the port 2 and the port 1 of the node N3 is confirmed as a route without a block port or a failure marking. Information is stored with sequence numbers 6 to 9 in FIG. Note that if there is no path without a block port or fault marking between the ingress node and the egress node (step C15), the process ends with an error (step C17).

  The above processing (steps C1 to C17) is repeated for all the L2 rings stored in the memory table 122 (step C18).

(4) Route connection processing (FIG. 12)
In the route connection process, the route information stored in the memory table 121 is connected, and the route of the selected path is specified. FIG. 12 shows the transition of the contents of the memory table 121 in this process for the example of FIG.

  FIG. 12 (1) is a copy of FIG. 7 (2), and the path connection process starts here. First, the memory table 121 is sorted in ascending order by sequence number to obtain a result as shown in FIG. Next, in FIG. 12 (2), duplicate data, that is, one of the data of sequence number 4 and the data of sequence number 5, and one of the data of sequence number 97 and the data of sequence number 98, respectively. By deleting, a result as shown in FIG. Finally, the sequence numbers in FIG. 12 (3) are reassigned to obtain the results as shown in FIG. 12 (4).

  In FIG. 12 (4), route information of a route without a block port or fault marking from the start node N5 to the end node N6 via the node N3 is presented. Subsequent communication is performed on this route instead of a route that does not pass through the node N3 in the normal time.

  The L2 layer route search has been described above, but in route search including the L3 layer, L3 node routing information and VRRP (Virtual Router Redundant Protocol) information are acquired, and via L3 switch processing is added. It is possible to determine the route.

  In this case, the route to the L3 switch is specified by the start / end node search processing. As a specifying method, the L3 switch that reaches the first from the start / end node is specified from the IP address set in the default gateway of the start / end node. If the VRRP virtual IP address is set in the default gateway, the VRRP information is obtained from the VRRP master node and standby node, and the L3 switch that reaches the valid L3 switch first from the start / end node As specified.

  Next, the routing information of the L3 switch that arrives first from the start / end node is acquired, and the L3 switch that passes next is specified. This is repeated to identify the L3 switch that passes between the start node and the end node. After this, as described in the first embodiment, the route of the L2 ring that passes through is specified, and the route of the path is determined.

1 server 2 network 3 LAN
10 CPU
11 Application
12 memory
13 Database
100 Memory access processor
101 Database access processor
102 Communication processor
110 Node access program
111 Route search program
120 L2 ring status information table
121 Route information table
122 Via L2 ring information table
130 Node information table
131 Physical link information table
132 L2 ring information table
133 Path information table
134 Fault information table
120a Node ID
120b port number
120c status information
121a Sequence number
121b Node ID
121c port number
122a sequence number
122b L2 ring ID
130a Node ID
130b IP address
130c login ID
130d login password
130e node type
130f Upper node ID
131a Link ID
131b from node ID
131c from port number
131d to node ID
131e to port number
132a L2 ring ID
132b L2 ring name
132c Node ID
132d port number
132e sequence number
132f Master node identifier
132g Upper ring ID
133a Path ID
133b Path name
133c Start node ID
133d End node ID
134a Fault ID
134b Node ID
134c port number

Claims (10)

A path route search method in an L2 layer network composed of L2 switches,
A procedure for pre-registering the network configuration information in the server;
A procedure for pre-registering path information specifying a start node and a terminal node in the server;
A procedure for registering failure information with the server when a failure occurs;
The procedure to acquire L2 ring block port information of the network at the time of path route search,
A path route search method, comprising: a step of searching for a route including neither a failure nor a block port by using the configuration information and using the path information, the failure information, and the L2 ring block port information.   The configuration information includes node-specific node information set for each node, physical link information indicating nodes and ports at both ends of each link for each link connecting the nodes, and connection of each node constituting the L2 ring. 2. The path route search method according to claim 1, comprising L2 ring information indicating an order together with a master node identifier and an upper L2 ring ID. The search is
A path from the start node to the L2 ring, and a start / end node search process for specifying a path from the end node to the L2 ring;
Via the L2 ring through which the path from the start node to the end node passes
L2 ring search processing,
L2 ring route search processing for specifying a route in the specified L2 ring;
3. The path route search method according to claim 2 , wherein route connection processing for connecting the results of the start / end node search processing, the via L2 ring search processing, and the L2 ring route search processing is performed in this order. In the start / end node search process, for each of the start node and the end node,
Obtaining a node type from the node information;
In the case where the node type is a star configuration node, a procedure for obtaining the upper node ID of the node from the node information;
A procedure for identifying a link between the node and the higher-level note from the physical link information;
Repeat the procedure for adding the route node and port number to the route information table ,
When the node type is a ring configuration node, a procedure for adding a routed node and a port number to the route information table;
4. The path route search method according to claim 3, further comprising a step of adding a routed L2 ring ID to the routed L2 ring information table. The via L2 ring search process is
A procedure for obtaining the L2 ring ID on the start node side from the via L2 ring information table,
If the L2 ring has an upper ring, a procedure for obtaining an upper ring ID from the L2 ring information;
A procedure for obtaining an L2 ring ID on the end node side from the via L2 ring information table;
A procedure for comparing the L2 ring ID and the upper ring ID;
In the case of a mismatch, a procedure for adding the upper ring ID to the via L2 ring information table;
A procedure for identifying a link with the L2 ring in the via L2 ring information table from the physical link information;
Repeat the procedure of adding the node and port number to be routed to the route information table,
If they match, the physical link information identifies the link with the L2 ring in the via L2 ring information table, and
5. The path route search method according to claim 4, further comprising a step of adding a node and a port number to be routed to the route information table. The L2 ring route search process is
A procedure for identifying an L2 ring ID from the via L2 ring information table;
A procedure to duplicate the L2 ring information in the ring status information table;
In the case of unsuccessful login to the master node, a procedure for marking the ring status information table as a failure,
If the login to the master node is successful, the ring status information is acquired, and if there is a block port, the procedure for marking the ring status information table,
A procedure for obtaining an ingress node and an egress node from the via L2 ring information table and marking the ring status information table;
A procedure for marking a failure in the ring status information table with reference to the failure information;
A procedure for searching the ring status information table to check a path without a block port and a fault marking between the entry node and the exit node;
6. The path route search method according to claim 5, further comprising a procedure of clearing the ring status information table by adding to the route information table if the family lesson is taken. The route connection process includes:
Sorting the route information table in ascending order by sequence number;
A procedure for deleting one of the duplicate data in the data of the route information table;
The path route search method according to claim 6, further comprising a procedure of reassigning a sequence number of the route information table. A route search method including the L3 layer,
Obtain the routing information of the L3 switch that arrives first from the start node and the end node, repeat the procedure to specify the L3 switch that passes next, and specify the L3 switch that passes between the start node and the end node The path route search method according to claim 3, wherein the path route search method is preceded by the start / end node search processing. The procedure for identifying the L3 switch is set in the default gateway of the start node and end node.
From the IP address, identify the L3 switch that arrives first from the start node and end node,
When the VRRP virtual IP address is set in the default gateway, the VRRP information is acquired from the VRRP master node and standby node, and the L3 switch that is enabled first arrives from the start node and end node. The path route search method according to claim 8, characterized in that:
  A program for executing the path route search method according to claim 1 in the server.

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