JPH11150553A - Switching hub with virtual lan function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the capacity of an address table by sharing the address table in VLAN between switches, adding ID identifying to which VLAN a frame belongs to a repeating frame and transferring the frame in the same VLAN. SOLUTION: A switching hub with virtual LAN function 10-1 is provided with a switching control part 14, a VLAN control part 11 and an address table 13, connects plural local area networks using CSMA/CD as an access control system with a transmission medium, simultaneously executes a repeating operation for respective ports and separates LAN into plural ones by setting. An inter-switch address management part 15 shares the address in VLAN between the switches. A VLANID processing part 16 adds or deletes ID for identifying to which VLAN the frame belongs to/from the repeating frame. An intra-VLAN transfer processing part 17 transfers the frame in the same VLAN.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a configuration in which a plurality of local area networks (LANs) using a medium access control system and CSMA / CD are connected. And a switching hub with a virtual LAN function.

[0002]

2. Description of the Related Art In a conventional switching hub having a virtual LAN function, a plurality of local area networks (LANs) using CSMA / CD as an access control method with a transmission medium are connected, and each port is simultaneously relayed for each port. , The LAN is separated into a plurality by setting, and an address table is created for each set virtual LAN.

FIG. 2 is a system configuration diagram for explaining a configuration example of a conventional switching hub having a virtual LAN function.

In this conventional example, as shown in FIG. 2, a VLAN control unit for identifying a plurality of VLANs set in advance and outputting a port number, a source address, a destination address and VLAN information for receiving a frame for each VLAN. 111 and V
An address table 113 in which addresses are managed for each LAN, a port number, a source address, and a destination address output from the VLAN control unit 111 are input, and the destination and source addresses are stored in the target VLAN table on the address table 113. Check that the address is registered,
The VLAN controller 111 is notified of whether or not the destination address is registered in the address table. If the destination address is registered, the port number is notified, and the source address is registered in the address table 113. If not, the address management unit 112 registers the address together with the port number in the address table 113;
VLA for each port output from VLAN control unit 111
According to the N information, when the destination address is registered in the address table 113 at the time of relaying the frame, the frame is relayed to the registered port. When the destination address is not registered in the address table 113, the same V
The switching control unit 114 relays frames to all ports belonging to the LAN.

[0005] In the system configuration shown in FIG.
Terminals 120-1, 120-2, 120-5, 120-6
To VLAN 1 and terminals 120-3, 120-4, 120-
7 and 120-8 are set to belong to VLAN2, the address tables 113 in the switching hubs 110-1 and 110-2 indicate that the end 120-1 and 12-2 are not included.
The address of 0-2, 120-5, 120-6 is VLAN
1 as the learning address in
The address of 20-4, 120-7, 120-8 is VLA
Each is registered as a learning address in N2.

[0006]

In the conventional switching hub with a virtual LAN function as described above, when a plurality of virtual LANs are set, the L of the end is not changed.
Since a table of MAC addresses, which are AN addresses, exists for each virtual LAN, a virtual L that can be set
A memory for storing a table of the number of ANs × the number of MAC addresses that can be learned in one virtual LAN is required.

For this reason, the number of virtual LANs that can be set depends on the maximum number of MAC addresses that can be learned in one virtual LAN in the device or the memory capacity of the address table of the entire device and is limited. There is a point.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional technology, and has been made in consideration of the above-described problems.
It is an object to provide a switching hub with an AN function.

[0009]

In order to achieve the above object, the present invention comprises a plurality of terminal communication LAN ports and a plurality of switch communication LAN ports; switching control means for controlling switching between the plurality of terminals; L by setting
A VLAN control unit for separating an AN into a plurality of units; and an address table management unit for managing an address table in a switch.
In a switching hub with a virtual LAN function, a plurality of local area networks using MA / CDs are connected, relay operations are simultaneously performed for each port, and a plurality of LANs are separated by setting.
Address management means for sharing the address table within the switch, and I / O identifying which frame belongs to which VLAN.
VLANID processing means for adding or deleting D to or from a relay frame, and VL for transferring a frame within the same VLAN.
And an intra-AN transfer processing means.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system configuration diagram for explaining an embodiment of a switching hub having a virtual LAN function according to the present invention.

In this embodiment, as shown in FIG. 1, a VLAN control unit 11 for identifying a plurality of VLANs set in advance and outputting a port number, a source address, a destination address, and VLAN information for receiving a frame for each VLAN. And VLA
Address table 13 in which addresses are managed for each N
And the port number, source address, and destination address output from the VLAN control unit 11, and confirms whether the destination and source addresses are registered in the table of the target VLAN on the address table 13, and performs VLAN control. Notifying the unit 11 whether the destination address is registered in the address table and, if so, notifying the port number, and noting the source address in the address table 13 Is
The address is stored in the address table 13 together with the port number.
Switch internal address management unit 12 that registers
If the destination address is registered in the address table 13 at the time of relaying the frame based on the VLAN information for each port output from the control unit 11, the frame is relayed to the registered port, and the destination address is stored in the address table 13. If the destination address is not registered, the destination address output from the switching control unit 14 is directly connected to the switching control unit 14 that outputs the destination address, and another book preset in the same VLAN is input. The switching hub checks whether the destination address is registered in the address table belonging to the same VLAN, and relays the frame to the same VLAN. To identify a frame belonging to VLAN And VLANID processing unit 16 for adding or deleting the ID to the relay frame, and a VLAN in the transfer processing unit 17 for performing the transfer of frames in the same LAN.

In the inter-switch address management unit 15, the following sequence is executed.

If the destination address belonging to the same VLAN is not registered in the own address table 13, the frame is transmitted to the VLAN controller 11 via the VLAN controller 11.
The target VLAN ID is added by the LANID processing unit 16, and the frame is transmitted to another switching hub directly connected to the LAN via the intra-VLAN transfer processing unit 17 and the switching control unit 14. When the frame to which the VLAN ID is added is received via the switching control unit 14 and the intra-VLAN transfer processing unit 17, the frame to which the VLAN ID is added from the intra-VLAN transfer processing unit 17 to the VLAN ID processing unit 16 is received. Is notified.

When the VLAN ID processing unit 16 is notified that the frame to which the VLAN ID has been added is received,
In the VLAN ID processing unit 16, the VL of the frame
The frame in which the ANID is deleted and the VLANID is deleted is notified to the inter-switch address management unit 15 via the VLAN control unit 11.

When the inter-switch address management unit 15 is notified, the inter-switch address management unit 15 checks whether the destination address of the frame is registered in the address table 13 belonging to the same VLAN and the VLAN control unit 11 and the switch. It is confirmed through the internal address management unit 12.

VL received from another switching hub
If the destination address of the frame to which the ANID is added is registered in the address table 13, the target port number is received via the in-switch address management unit 12 and the VLAN control unit 11, and accordingly, the VLAN
The frame is relayed to the target port via the internal transfer processing unit 17 and the switching control unit 14.

If not registered, the same VL
The frame is relayed to all ports belonging to the AN.

In the system configuration shown in FIG.
VLA for terminals 20-1, 20-2, 20-5, and 20-6
When N1 and the terminals 20-3, 20-4, 20-7, and 20-8 are set to belong to the VLAN 2, the address table 13 in the switching hub 10-1 indicates that the terminals 20-1, 20-2 If the address is a learning address in VLAN 1 and the addresses of terminals 20-3 and 20-4 are V
Each address is registered as a learning address in the LAN 2, and is stored in the address table 1 in the switching hub 10-2.
3, the address of the terminal 20-5 and 20-6 is V
Registered as a learning address in LAN1,
The addresses 7 and 20-8 are registered as learning addresses in VLAN2.

[0020]

As described above, according to the present invention, the number of addresses registered in the address table in the VLAN of two switching hubs directly connected can be reduced.

Thus, the capacity of the address table in one switching hub can be reduced.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram illustrating an embodiment of a switching hub having a virtual LAN function according to the present invention.

FIG. 2 is a system configuration diagram for explaining a configuration example of a conventional switching hub having a virtual LAN function.

[Explanation of symbols]

 10-1 to 10-3 Switching Hub 11 VLAN Control Unit 12 Intra-Switch Address Management Unit 13 Address Table 14 Switching Control Unit 15 Inter-Switch Address Management Unit 16 VLANID Processing Unit 17 Intra-VLAN Transfer Processing Unit 20-1 to 20-8 Terminal

Claims (1)

[Claims] 1. A plurality of terminal communication LAN ports and a switch communication LAN port; switching control means for controlling switching with the plurality of terminals; VLAN control means for separating a LAN into a plurality of pieces by setting; Address table management means for managing an address table of a plurality of local area networks using a CSMA / CD as an access control method with a transmission medium, simultaneously performing a relay operation for each port, and setting a LAN
In a switching hub with a virtual LAN function, an inter-switch address management means for sharing an address table in a VLAN between switches, and a VLAN ID for adding or deleting an ID for identifying which frame belongs to a relay frame to a relay frame Virtual LAN, comprising: processing means; and intra-VLAN transfer processing means for transferring a frame within the same VLAN.
Switching hub with functions.