JPH10145411A - Switching hub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a virtual LAN including plural switching hubs by discriminating the repetition destination port of a received frame based on network virtual LAN information. SOLUTION: Memory areas 741, 751, 761, 742, 752 and 762 of switching hubs 1 and 2 (701 and 702) respectively store port information, present station virtual LAN information and network virtual LAN information. When a broadcast frame transmitted by a terminal 1 (731) is received, the switching hub 2 (702) reads a virtual LAN number corresponding to the transmission source MAC address of the received frame out of the memory area 762 for the network virtual LAN information. In this case, the virtual LAN number corresponding to a MAC address '00000001' of the terminal 731 is '10'. Then, while referring to the port information in the memory area 742, the switching hub 2 (702) repeats the broadcast frame only to a LAN port 1 (721) corresponding to the virtual LAN number '10'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching hub having a virtual LAN function, and more particularly, to a switching hub capable of realizing a virtual LAN even in a network including a plurality of switching hubs.

[0002]

2. Description of the Related Art A virtual LAN groups devices connected to a network regardless of their physical wiring and configuration. The group described here indicates a range that a MAC frame corresponding to the second layer of the OSI reference model can reach. Note that a router that performs a relay operation in the third layer of the OSI reference model is used in principle for communication between different groups.

[0003] Conventional switching hubs include ports and MAs.
The networks are grouped based on the C address. As an example of grouping, a network that is grouped based on ports will be described. As shown in FIG.
A terminal such as a personal computer is connected to each of the plurality of LAN ports. LAN ports 1, 2, 3 (311,
312, 313) belong to group 1 and the LAN ports 3, 4, 5, 6 (313, 314, 315, 316) belong to group 2. The thick line with the arrow is the path of the broadcast frame. As shown by this route, the terminal 4
The broadcast frame transmitted by (324) is relayed to terminals 3, 5, 6 (323, 325, 326),
It is not relayed to the terminals 1 and 2 (321 and 322). Since the relay was performed to all the terminals before the grouping, the network load is reduced by the grouping.

[0004] A broadcast frame is a frame in which a broadcast address is stored in a destination address. FIG. 5 shows an Ethernet MAC address as an example of the destination address. MAC address (401)
Has an I / G bit at the beginning, and the I / G bit is "0".
If it is, it is a unicast address (402), and if the I / G bit is "1", it is a multicast address (403).
However, if all the bits are “1”, it is the broadcast address (404). Thus, the Ethernet broadcast address is a special address in which all bits are “1”.

[0005] As in the case of the LAN port 3 (313) in FIG. Terminal 3 (32) connected to the duplicated port
3) is all other terminals 1, 2, 4, 5, 6 (321,
322, 324, 325, and 326). However, the broadcast frame transmitted by the terminal 3 (323) is relayed to all ports except the own LAN port 3 (313).

Next, processing of a virtual LAN by a conventional switching hub will be described. FIG. 6 shows a configuration of a conventional switching hub. As shown in the figure, the conventional switching hub has transmission lines 1, 2, 3 (221, 222,
223) connected to LAN ports 1, 2, 3 (21
1, 212, 213), a relay circuit (204) for relaying between ports, a processor (201), and a ROM (20).
3) and a memory (202). When the switching hub recognizes the electric signal of the transmission path 1 (221) as a frame at the LAN port 1 (211), it sends the signal to the relay circuit (204). If the received frame is a broadcast address or a destination address whose destination port is unknown in the relay circuit (204), the memory (20)
Referring to the virtual LAN setting stored in 2), data is relayed to a port in the same group as the receiving port. For example, LAN port 1 (211) and LAN port 2 (2
12) is the same group, and LAN port 1 (21)
When the group 1) and the LAN port 3 (213) are different groups, the data is relayed to the LAN port 2 (212),
It does not relay to LAN port 3 (213).

Further, a description will be given of processing of a virtual LAN in a network configured by using a plurality of conventional switching hubs. FIG. 7 shows a network configured using two conventional switching hubs. In FIG. 7, LAN port 1 of switching hub 1 (501)
(511) is a group of virtual LAN number “10”, LA
It is assumed that the N port 3 (513) is set to the group of the virtual LAN number “20”. The LAN port 1 (521) of the switching hub 2 (502) is a virtual L
The group of AN number “10”, LAN port 3 (52
3) is assumed to be set in the group of the virtual LAN number “20”. Switching hubs 1 and 2 (501,
The setting content of 502) is stored in a predetermined memory area (541, 542) as tabular data.

The terminal 1 (531) and the terminal 3 (533) belonging to the group with the virtual LAN number "10" and the terminal 2 (53) belonging to the group with the virtual LAN number "20"
2) and the terminal 4 (534), the LAN port 2 of the switching hub 1 (501) is required to enable communication.
(512) and the LAN port 2 (522) of the switching hub 2 (502) are connected to the virtual LAN numbers "10" and "2".
It is necessary to duplicate the settings so that they belong to the group of "0".
Suppose LAN port 2 of switching hub 1 (501)
(512) and LAN of switching hub 2 (502)
Port 2 (522) is not duplicated and virtual LAN number "1"
0 ", the terminal 2
Communication between (532) and terminal 4 (534) becomes impossible. However, if duplicate settings are made, the virtual LAN number “1”
The broadcast frame transmitted by the terminal 1 (531) belonging to the group 0 "is the LAN of the switching hub 2 (502) belonging to the group having the virtual LAN number" 20 ".
It is also relayed to port 3 (523).

[0009]

A conventional switching hub is an LA that is set to overlap with a plurality of groups.
Since a broadcast frame received from an N port is relayed to all overlapping groups, a virtual LAN cannot be realized in a network configured using a plurality of switching hubs.

Accordingly, an object of the present invention is to solve the above problems and to provide a switching hub that can realize a virtual LAN even in a network including a plurality of switching hubs.

[0011]

According to the present invention, one or a plurality of virtual LAN groups belonging to each of a plurality of ports connected to a network are set in advance, and the identification numbers of the groups are set. Identification number setting means for storing corresponding to the port, self-station virtual LAN information collection means for storing the identification number of the group to which the receiving port belongs at the time of frame reception and the source MAC address in the received frame as virtual LAN information, A virtual LAN for transmitting a frame including the virtual LAN information to a network
Information notifying means, network virtual LAN information collecting means for receiving the frame including the virtual LAN information from the network and storing the virtual LAN information, and determining a relay destination port of the received frame based on the network virtual LAN information And relay determination means.

[0012] The virtual LAN information notifying means may periodically transmit the frame.

The virtual LAN information notifying means may transmit the frame immediately when the change of the virtual LAN information of the own station occurs.

[0014]

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

The network shown in FIG. 1 is configured by using two switching hubs of the present invention. The switching hubs 1, 2 (701, 702) are connected to a plurality of LAN ports 1, 2, 3 (711, 71) connected to the network.
2, 713) and (721, 722, 723), an ID number setting means for setting one or a plurality of virtual LAN groups belonging to each of them in advance, and storing the ID numbers of the groups in association with the LAN ports; Own-station virtual LAN information collecting means for storing the identification number of the group to which the receiving port belongs and the source MAC address in the received frame as virtual LAN information, and virtual LAN information for transmitting a frame including the virtual LAN information to the network Notifying means, network virtual LAN information collecting means for receiving a frame including the virtual LAN information from the network and storing the virtual LAN information, and relay for determining a relay destination port of the received frame based on the network virtual LAN information Determination means. Each of the memories of the switching hubs 1 and 2 (701, 702) has a tabular memory area (741, 751, 761,
742, 752, and 762), and identification number setting information (called port information) is stored in a memory area (741, 74).
In (2), the local LAN information is stored in the memory area (751, 7).
52), the network virtual LAN information is stored in the memory area (761, 762).

The identification number setting means and the own station virtual LAN information collecting means will be described. FIG. 2 shows the configuration of the switching hub of the present invention. The switching hub of the present invention includes a processor (101) for executing a program, a memory (102) capable of reading and writing data, and an RO for storing a program.
M (103), multicast transmission / reception circuit (104),
A relay circuit (105), a timer for measuring time (10
6), LA connected to transmission lines 121, 122, 123
It is composed of N ports 1, 2, 3 (111, 112, 113).

The switching hub of the present invention can group ports in the same manner as a conventional switching hub. The difference from the related art is that the identification number of each group is a common virtual LAN number in the network.

The processor (101), according to the command of the administrator, sets the port number and the virtual L assigned to the port.
The AN number and the port number are stored in the memory (102). For example, after storing the port number and the virtual LAN number in the register of the processor (101),
Call the port information setting program in (103).
Port number and virtual L by port information setting program
Port information including an AN number (group identification number) is stored in a memory area in a table format. In the example of FIG.
The group to which the N port 1 (611) and the LAN port 2 (612) belong is set as the group of the virtual LAN number “10”, and the group to which the LAN port 3 (613) and the LAN port 4 (614) belong is the virtual LAN. Number "2
The port information is set in the table-type memory area 64 in the switching hub (601).
1 is stored.

When the switching hub receives a frame,
The virtual LAN number of the group to which the receiving port belongs and the source MAC address in the received frame are stored as virtual LAN information. In the example of FIG. 3, the MAC address “0”
The frame transmitted by the terminal 1 (631) having "0000001" is received from the LAN port 1 (611). Similarly, the frame transmitted by the terminals 2, 3, 4 (631, 632, 633) is transmitted to the LAN port 2, 3 , 4 (612, 61
3,614). By receiving these frames, virtual LAN information is collected. The virtual LAN information is stored in a tabular memory area 651 in the switching hub (601).

Next, the virtual LAN information notifying means will be described. The switching hub of the present invention uses the timer (106) to periodically transmit a frame including virtual LAN information to another switching hub. The destination of the frame to be transmitted to all switching hubs connected to the network is the multicast address (403) in FIG.
The reason for using a multicast address is that a unicast address (402) or a broadcast address (40
This is because, when 4) is used, the conventional switching hub on the network may not relay the frame. Thus, the switching hub of the present invention uses one of the multicast addresses for notification of virtual LAN information. The timer (106) of FIG.
Issue a periodic interrupt signal to 1). When the processor (101) receives this interrupt, the memory (10)
A frame including the virtual LAN information stored in 2) and having the specified multicast address as the destination address is created. After creating the frame, the processor (101) requests the multicast transmission / reception circuit (104) to transmit the frame from all LAN ports. According to this request, the multicast transmission / reception circuit (104)
The frame is transmitted from the AN ports 1, 2, 3 (111, 112, 113).

Next, the network virtual LAN information collecting means will be described. When the destination address of the received frame is the above-defined multicast address, the switching hub of the present invention extracts the virtual LAN information in the frame and stores it in the memory area of the network virtual LAN information.

Next, returning to FIG. 1, the relay determining means will be described. In FIG. 1, L of the switching hub 1 (701)
The AN port 1 (711) belongs to the group of the virtual LAN number “10”, and the LAN port 3 (713) is the virtual LAN number.
The LAN port 1 (721) of the switching hub 2 (702) belongs to the group of the virtual LAN number "10", and the LAN port 3 (723) is set to belong to the virtual LAN number "20". Of the switching hub 1 (701).
AN port 2 (712) and switching hub 2 (70)
The LAN port 2 (722) of 2) is set so as to overlap with the group of virtual LAN numbers "10" and "20".

Switching hubs 1 and 2 (701, 70)
2) memory area (741, 751, 761, 742,
752, 762) store port information, own-station virtual LAN information, and network virtual LAN information, respectively, by the operations of the means described above.

Here, the switching hub 2 (702)
When receiving the broadcast frame transmitted by the terminal 1 (731), the virtual LAN number corresponding to the source MAC address of the received frame is set to the network virtual LA.
The N information is read from the memory area (762). According to the network virtual LAN information, the MA of the terminal (731)
Virtual LAN corresponding to C address "00000001"
The number is “10”. Switching hub 2 (702)
Refers to the port information in the memory area (742), and refers to the LAN port 1 (72) corresponding to the virtual LAN number “10”.
Relay the broadcast frame only in 1). LA
Since the virtual LAN number does not correspond to the N port 3 (723), no relay is performed.

In the above embodiment, the virtual LAN information notifying means periodically transmits the multicast frame including the virtual LAN information.
When the change of the N information occurs, the virtual LAN information may be stored in a multicast frame and transmitted immediately.

[0026]

The present invention exhibits the following excellent effects.

(1) Since the relay port of the received frame is determined based on the network virtual LAN information from another switching, the broadcast frame can be transmitted only to the virtual LAN group, and a plurality of switching can be performed. A virtual LAN can be realized in a network configured using a hub.

(2) Since the network virtual LAN information is collected, the network administrator can easily grasp the setting status of the virtual LAN by referring to the network virtual LAN information. It is possible to prevent such communication failure from occurring.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a network using two switching hubs according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a switching hub of the present invention.

FIG. 3 is a configuration diagram of a network using one switching hub of the present invention.

FIG. 4 is a configuration diagram of a network using one conventional switching hub.

FIG. 5 is a configuration diagram of a MAC address.

FIG. 6 is a configuration diagram of a conventional switching hub.

FIG. 7 is a configuration diagram of a network using two conventional switching hubs.

[Explanation of symbols]

701, 702 Switching hubs 711-713, 721-723 LAN ports 731-734 Terminals 741, 742 Port information memory area 751, 752 Own station virtual LAN information memory area 761, 762 Network virtual LAN information memory area

Claims (3)

[Claims] 1. An identification number setting means for setting one or more virtual LAN groups belonging to each of a plurality of ports connected to a network in advance, and storing an identification number of the group in association with the port, and receiving a frame. Self-station virtual LAN information collection means for storing the identification number of the group to which the receiving port belongs and the source MAC address in the received frame as virtual LAN information;
Virtual LA for transmitting a frame containing information to a network
N information notifying means, network virtual LAN information collecting means for receiving a frame including the virtual LAN information from the network and storing the virtual LAN information, and determining a relay destination port of the received frame based on the network virtual LAN information A switching hub, comprising: 2. The switching hub according to claim 1, wherein said virtual LAN information notifying means transmits said frame periodically. 3. The switching hub according to claim 1, wherein said virtual LAN information notifying means transmits said frame immediately when a change in virtual LAN information of its own station occurs.