JPH09149084A - Virtual network routing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the response speed in the system and to save resources in the ATM(asynchronous transfer mode). SOLUTION: Hub 12, 13 have plural ports 1 to 7 and a bridge function and are connected via an ATM network 11 and the ports 1-7 are grouped to set a V(virtual) LAN. Hubs 12 and 13 respectively have virtual routers 14 and 15, and a physical address table in which port information corresponding to a physical address is registered and transfers data based on the registered contents of the table. Information is added to the physical address table so that data to be sent is transferred to a virtual router of its own hub when metrics information of the received routing information in the case where the information is relayed through the virtual router of its own equipment is the same as the one in the case where it is relayed through the other virtual router.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a routing method for a virtual network such as a virtual LAN constructed via a backbone network such as an ATM (asynchronous transfer mode) network.

[0002]

2. Related Background Art Conventionally, when a hub, which is a connection device, is used by connecting to a high speed network such as an ATM network, a plurality of separated LANs are irrelevant regardless of the physical configuration.
It is known to build a (virtual LAN).
A typical virtual LAN configuration is, for example, A
A hub configured based on the TM-IEEE802.3 standard has a high-speed backbone ATM interface, and a packet configured based on the IEEE802.3 standard by using LAN emulation standardized by the ATM forum (hereinafter Simply referred to as "packet") to the ATM side interface.

In LAN emulation, different emulated LANs (hereinafter referred to as "ELANs") can be provided, and ports configured according to the IEEE802.3 standard of the hub (hereinafter simply referred to as "ports")
Which emulated LAN is assigned to each can be set by software, and as a result, a plurality of independent LANs (virtual LANs) have been constructed without changing the physical wiring. Then, a broadcast packet does not pass between different virtual LANs, and nodes belonging to different virtual LANs are separated from each other and cannot directly communicate with each other.

Therefore, there is a system in which, when communication is performed between nodes of different virtual LANs, the virtual LAN is connected via an external router to enable data communication between the virtual LANs.

[0005]

However, when the above-mentioned external router is used, the router and the hub must be used properly according to the application, and the number of parts increases and
There is a problem that the cost and the installation space increase. Further, as disclosed in Japanese Patent Laid-Open No. 5-292091, there has been one that has a router function and a bridge function in one internetwork device to reduce the cost and installation space. In this case, for example, a plurality of the internetwork devices are connected via an ATM network and data communication is performed via the internetwork device. However, this internetwork device is not designed in consideration of an algorithm that determines which router is used when there are two routers connected to two networks.

Therefore, when the metrics number indicating the distance to the destination (the number of routers performing data relay) is the same, the packet is connected via the ATM to the internetwork device which is substantially distant. Transmission may be set up. In this case, since the ATM network is used, the response speed becomes slow and A
There is a problem that the TM network is unnecessarily used and resource saving cannot be achieved.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a virtual network routing method that speeds up the response speed in the system and saves resources of the backbone network.

[0008]

In order to achieve the above object, according to the present invention, a plurality of hubs having a plurality of ports to which each node is connected and a bridge function are provided.
In a system that connects via a network, groups predetermined ports with other hubs, sets a virtual LAN, and transmits data between the nodes, each hub includes a virtual router and A virtual router and a physical address table in which port information corresponding to the physical address information of the node is registered, the transmitted data is transferred based on the registered contents of the table, and the routing from the other hub is performed. When the information is received and the metrics information indicating the distance to the partner network in the routing information is the same as when the virtual router of the own device is relayed and when the router of another hub is relayed,
The physical address information and the corresponding port information are registered in the table so that the transmitted data is transferred to the virtual router, and when the metrics are the same, the transmission data is transferred to the virtual router. A routing method for a virtual network is provided that aims at speeding up response speed.

At the same time when the virtual router of the own device is relayed and when the router of another hub is relayed, the physical address registered in the table is the information of the virtual router of the own device. The corresponding port information is
It is desirable that the information is set to the port of the virtual router.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A virtual network routing method according to the present invention will be described with reference to the drawings of FIGS. FIG. 1 is a configuration diagram showing a configuration of an embodiment of a virtual LAN system using a virtual network routing method according to the present invention. In the figure, in a virtual LAN (hereinafter referred to as "VLAN") system, A
It has a high-speed network such as the TM network 11 in its backbone, and is configured by connecting a plurality of hubs 12 and 13 as connecting devices to branch lines.

The hubs 12 and 13 are, for example, ATM-10B.
A function of a router, which is composed of a conversion device that connects ASE-T interfaces to each other and is configured to support a routing protocol by software or the like (hereinafter, this function of the router is referred to as a "virtual router"). That is). The hubs 12 and 13 include, for example, ports 1 to 7 to which each network node (hereinafter simply referred to as “node”) is connected,
The virtual router has ports 8 and 9 and ATM network side port 10, respectively, and bridging connection at the MAC layer level between ports 1 to 7 of its own device and between ATM network side ports 10 with other hubs. It is carried out.

The hubs 12 and 13 have a VLAN function, and it is possible to independently set which VLAN each of the ports 1 to 7 belongs to. Different VLAN is AT
On the M network 11, they are identified as different emulated LANs. This allows the VLAN to
It is possible to build across three. In this embodiment, nodes 21 to 27 are connected to the ports 1 to 7 of the hub 12, and nodes 31 to 37 are connected to the ports 1 to 7 of the hub 13. The nodes 21 to 23 and the nodes 31 to 34 construct the VLAN 50, and the node 24
27 and nodes 35 to 37 form a VLAN 60.

A VLAN 50 and a VLAN 60 are connected to the virtual router 14 of the hub 12 and the virtual router 15 of the hub 13, respectively.
It has a function of routing between 60 using a known routing protocol. Therefore, for example, the virtual router 14 can receive the routing information transmitted from the virtual router 15 supporting the same kind of routing protocol periodically or when changing the conditions.

The virtual router 14 creates a routing table based on the routing information obtained by this routing function, and Table 1 is an example of the above routing table based on IP (Internet Protocol).

[0015]

[Table 1]

In Table 1, the network entry registers the network address of the VLAN connected to the virtual router 14, and the port entry lists the V address.
The network address of the port to which the LAN is connected is registered, the data entry VLAN or router network address is registered in the gateway entry, and the distance to the destination (actually data relay The number of routers to do) is registered.

The virtual router 14 can obtain information on the virtual network address of the router 15 from the frame containing the routing information. For example, when the protocol is TCP / IP, this address information and A
The physical address of the router 15 can be recognized from the information of the RP protocol. Also, the protocol is IPX
If it is, the physical address of the router 15 can be recognized from the lower 6 bytes of the network number.

The virtual router 14 has a physical address table shown in Table 2.

[0019]

[Table 2]

In Table 2, the physical address entry is, for example, the address “11.11.11.
11.11.11 ”, the address of the port 8 of the router 14“ 22.22.2.22.22.22.22 ”, the router 15
Address of port 8 of "33.33.33.33.3"
3.33 ”, the address of the node 27 is“ 44.44.4.
4.44.444. ”Are registered respectively.
Further, in the port entry, the network address of the port to which the frame is transferred is registered.

The hub 12 transfers the frame processed by the internal bridge function in each direction according to the information registered in the physical address table.
Further, the hub 12 registers various information in the table based on the packet from the virtual router 15 by the normal bridge automatic learning function. That is, the virtual router 14
At the timing of exchanging routing information, etc.
The entry of the physical address table is added based on the flowchart of FIG. In FIG. 2, first, the virtual router 14 checks the routing table at the above timing (step 101) and determines whether or not there are a plurality of routing information, that is, a plurality of routes in the same VLAN (step 102).

If there are a plurality of routes, it is judged whether or not there is a router entry in the gateway of the routing information (step 103). It is determined whether the router is the same virtual router (step 104).
Whether or not the router is the same as the virtual router can be determined by the physical address of each router, for example, and the physical address of this router can be recognized by broadcasting between the virtual routers.

If the router is a virtual router, the corresponding port entry in the physical address table is set as its own router (step 105), and the above operation is terminated. That is, in Table 1, two routes exist in the VLAN 50, and the virtual router 15 which is the same as the self router is included in the information of the gateway. Therefore,
The virtual router 14 uses the address “33.33.33.3” of the port 8 of the router 15 in the physical address table.
Register the port number of port 8 of the router itself as the port entry corresponding to "3.33.33" (in Table 2,
That is the entry in the third row from the top). And
When the hub 12 receives a frame whose destination designates the port 8 of the virtual router 15, the hub 12 transmits the frame to the virtual router 14. Upon receiving the frame, the virtual router 14 determines whether or not the destination address is the address of its own router, and if different, sets the destination address as the address of its own router.

Therefore, in the virtual router 14, the metric information indicating the distance to the destination among the routing information of the nodes connected to the own device is the virtual router 14 of the own device.
At the same time as when the virtual router 15 of another hub 13 is relayed, so that the frame is transferred to the virtual router 14 of its own device, the next address (relay destination) is added to the physical address of the physical address table. ) And the port number of the virtual router 14 corresponding thereto can be added and registered.

The physical address table is used to search the output port number of a packet based on the destination address (physical address) in the packet.
Table 3 is another embodiment of the physical address table.

[0026]

[Table 3]

Table 3 shows a case where priority information corresponding to a physical address and a port is added. In the above priority, “0” indicates a non-priority case, and “1” indicates a priority case. In Table 3, the physical address is the address "33.33.3" of the port 8 of the router 15.
3.33.33.33 ”indicates that the frame is preferentially transferred to the pseudo-added port 8 of the virtual router 14. Therefore, even if there are a plurality of entries having the same physical address in the physical address table, the frame can be preferentially transferred to the specific port by the information indicating the priority. Therefore, for example, a packet to the VLAN 60 sent to the router 15 passes through the router 14 regardless of whether the destination address is for the virtual router 15 or the virtual router 14.

In the hub 12, the frame for the virtual router 15 sent from the virtual router 14 is transferred to the ATM port 10 registered in the port of the physical address table so as not to return to the virtual router 14 again. The priority is set low for the entry. In addition, the pseudo-added physical address is not used for sending a packet or responding to an ARP so as not to conflict with the actual physical port of the router 15.

FIG. 3 is a block diagram showing an example of the configuration of a bridge that manages the above-mentioned physical address table. In the figure, the transfer controller 40 sends a frame to a port of its own device (ports 1 to 7, ATM port 10), for example.
Alternatively, when fetched from the router 14, the physical address table 41 is searched from the destination address (physical address) of the frame and the corresponding transfer destination (ports 1 to 7, AT
The frame is transferred to the M port 10 or the router 14).

The frame for data transmission in the virtual LAN system is, for example, in the case of ARP,
The structure is as shown in FIG. In the figure, a frame is composed of a MAC layer header composed of a destination address and a source address composed of a physical address, an IP address composed of a network address, etc., data, and an FCS indicating the end of the frame.

Next, an embodiment of the frame communication procedure in the VLAN system shown in FIG. 1 will be described with reference to the procedure diagram of FIG. Note that, here, a case where a frame is transmitted from the node 21 to the node 27 will be described. Therefore, the physical address table of the hub 12 is shown in Table 3, and the routing table of the node 21 is shown in Table 4.

[0032]

[Table 4]

In FIG. 5, the node 21 is the node 2
When a packet for 7 is generated, a frame (see FIG. 4) is created by referring to the routing table in the own node. In this case, there are two routes for transmitting the frame to the node 27 belonging to the VLAN 60, and both metrics are "1". Therefore, the destination can be the router 15 or the router 14. However, in the node 21, as shown in Table 4, the gateway is set to the router 15 first, so that the destination address of the frame is the physical address “33.33.33.3.33” of the port 8 of the router 15. .33.33 ”, the transmission source is the node 21 physical address“ 11.11.11.11.
11.11. ”Is set and transmitted.

When the transfer controller 40 of the hub 12 receives the frame from the port 1, the transfer controller 40 of the physical address table 4
1 entry to the destination address “33.33.3”
3.33.33.33 ”. And
Although it matches the entries of the physical addresses of the two routers 15, the entry of the pseudo-added physical address of the router 15 has a higher priority here. The frame is transferred to the router 14.

When the router 14 receives the above frame, it removes the MAC layer header and treats it in the same manner as a frame sent directly to its own router. That is, the network address in the MAC layer header and the routing table of the router 14 are referred to and the frame is transmitted in a predetermined direction (in this embodiment, the port 7 belonging to the VLAN 60 via the port 9).

The destination address of the frame at this time is the address "44.44.44.44.
44.44 ”, and the transmission source address is set to the address“ 22.22.2.22.22.22.22 ”of the port 8. Therefore, the node 27 can receive the frame addressed to its own node. In the present embodiment, when there are a plurality of routes between virtual networks extending over the ATM network, the route having the faster response speed is always selected and the frame communication is performed, so that the response speed in the system is increased. At the same time, the above-mentioned ATM network can be used only when the communication requires the ATM network, and a routing method for saving the resources of the ATM network can be realized.

Further, in this embodiment, since the routing (data transfer destination) is controlled by using the physical address, the versatility is good and it is possible to use it for various kinds of protocols. Further, in the present embodiment, since the condition for adding the physical address entry is determined by the existing routing protocol, it is not necessary to add a new control protocol between the routers, which reduces the development time and development cost. Can be achieved.

In this embodiment, an example of the routing table in the node is shown in Table 4. However, if the hub is the default gateway type, it can be set as shown in Table 5 below. is there.

[0039]

[Table 5]

In the routing table shown in Table 5, the same VL as that of the own node (for example, the router 21 in FIG. 1) is used.
For an AN (in this example, virtual network 1) and a destination (for example, nodes 22 and 23) within the same hub, a data relay VLAN (in this example, virtual network 5).
Set 0) to send a frame. In addition, under the above condition, that is, in the same VLAN as the own node and the destinations (nodes) in the same hub, any one of the conditions is different, the table is set to send the frame to the router 14. Also in this case, it is possible to select the route with the faster response speed for frame communication, so that the response speed in the system can be increased and the resources of the ATM network can be saved.

Further, in this embodiment, even when the number of virtual networks handled by the router is three or more, the same method as in the above embodiment can be used regardless of the number of virtual networks handled. Also, in the hub of this embodiment,
ATM side interface and ATM side port-10
Between the BASE-T interface, LAN emulation v standardized by the ATM Forum LAN
It is possible to use a proprietary encapsulation that allows packet exchanges such as 1.0 or other, eg peer-to-peer.

Furthermore, in the present embodiment, the ATM network is used as the backbone network, but the present invention is not limited to this, and wide area networks (wide area networks) other than the ATM network, such as leased lines, frame relays, ISDN, etc. ,
It can be used in the same manner as in the above embodiment.

[0043]

As described above, according to the present invention, a plurality of connecting devices each having a plurality of ports to which each node is connected and a bridge function are connected via a backbone network to provide another connecting device. In a system in which a predetermined port is divided into groups to set a virtual network and data is transmitted between the nodes, each of the connection devices includes a virtual router and a physical address information of the virtual router and the node. Storage means for registering corresponding port information, transferring the transmitted data based on the registered contents of the storage means, receiving routing information from the other connection device, The information indicating the distance to the other party's network of the router of the other device At the same time as when the data is transferred, the physical address information and the corresponding port information are registered in the storage means so that the transmitted data is transferred to the virtual router of the own device. The response speed is increased, and the backbone network can be used only when necessary, so that the backbone network resources are saved.

According to a second aspect of the present invention, when the routing is the same when the virtual router of the own device is relayed and when the router of another connecting device is relayed, the physical address registered in the storage means is the own device. Virtual router information,
Since the corresponding port information is the information set in the port of the virtual router, the data can be transferred to the virtual router of the own device, which allows the backbone network to be used only when necessary and the short time. It becomes possible to transmit data over a distance.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of an embodiment of a virtual LAN system using a virtual network routing method according to the present invention.

FIG. 2 is a flowchart for explaining addition of an entry in a physical address table performed by the hub shown in FIG.

FIG. 3 is a block diagram showing an example of a configuration of a bridge that manages a physical address table shown in Table 3.

4 is a configuration diagram showing a configuration of a frame for data transmission in the VLAN system shown in FIG.

5 is a procedure diagram for explaining an example of a frame communication procedure in the VLAN system shown in FIG.

[Explanation of symbols]

 1-10 port 11 ATM network 12,13 hub 21-27, 31-37 node 40 transfer controller 41 physical address table 50,60 virtual LAN (VLAN)

Claims (2)

[Claims] 1. A plurality of connecting devices having a bridge function and a plurality of ports to which each node is respectively connected are connected via a backbone network, and predetermined ports are grouped with other connecting devices. In the system for setting a virtual network and transmitting data between the nodes, each of the connection devices includes a virtual router and a storage unit that registers port information corresponding to physical address information of the virtual router and the node. Information for transmitting the transmitted data based on the registered contents of the storage means, receiving routing information from the other connection device, and indicating the distance to the destination network in the routing information. However, when it is the same as when the router of the own device is relayed and when the router of another connection device is relayed, To forward the data to the virtual router of the own device, and the physical address information in the storage unit, routing method of the virtual network and registers the port information corresponding thereto. 2. The physical address registered in the storage means at the same time when the virtual router of the own device is relayed and when the router of another connection device is relayed, The virtual network routing method according to claim 1, wherein the virtual network routing information is information, and the port information corresponding thereto is information set in a port of the virtual router.