JPH0964899A - Mount system for module of switching hub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the mount system of a module of a switching hub in which independence of the module is enhanced and the processing by an interface module is simply attained. SOLUTION: A virtual port 2a to make communication with a host module 4 is provided to an interface module 3. Learning and retrieval of a MAC address are conducted through the virtual port 2a the same as other ports by means of a filtering database and a frame is relayed therethrough.

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 lower module for filtering and an upper module thereof, and more particularly, to a switching hub which enhances module independence and simplifies processing in an interface module. It relates to the mounting method of the module.

[0002]

2. Description of the Related Art A switching hub looks up a destination address of a received frame (packet), searches an internal filtering table, and relays the packet to a port corresponding to the destination address. If no entry (registration) of the destination address of the packet is found in the filtering table, the packet is relayed to all ports. At the same time, the transmission address and reception port of the packet are registered in the filtering table.

The switching hub is internally equipped with an IP module and an ARP module in order to communicate with an external host. Here, the IP module
The ARP module is a means for executing IP (Internet Protocol), which is a protocol for selecting a communication path, and the ARP module is a means for executing ARP, which is a protocol for acquiring a MAC address. The MAC address is an address held by the MAC which is a means for controlling access to a communication medium such as a LAN. IP is Internet P
Abbreviation of rotocol, ARP is Address Resolution Protocol
Is an abbreviation for Medium Access Control.

Since these IP module and ARP module are higher than the interface module for the transmission / reception port connected to the network, they are called upper modules and the interface modules are called lower modules.

In the IP module, which is a higher-level module, usually one IP address corresponds to one MAC address. On the other hand, the interface module, which is a lower module, has a plurality of MAC addresses corresponding to the number of ports.

There are the following two methods for the interface module to set the source MAC address field of the MAC frame.

[0007] One method is to set the MAC address of each port in the destination address field of the MAC header.

The other method is to set the MAC address of the upper module in the source MAC address field of the MAC header at all ports.

[0009]

A problem will be described about a method in which the interface module sets the MAC address of each port in the destination address field of the MAC header.

In this method, the lower module recognizes the MAC address corresponding to each port, while the upper module recognizes only one MAC address corresponding to the IP address. Therefore, inconvenience may occur in communication.

For example, the switching hub 41 shown in FIG.
In the above module configuration, the lower module 43 is M
AC address; MAC (b), MAC (c), MAC
(D), ..., MAC (x) are respectively recognized, and the upper module 44 receives the IP address; A and the MAC address; MA.
It recognizes C (a). In this configuration, the ARP protocol is used to acquire the MAC address corresponding to the IP address of the external host. FIG. 5 shows the address portion of the ARP frame when the ARP frame is transmitted via the port 42b.

In FIG. 5, the contents of the source MAC address field 54 of the MAC header part 51 are MAC.
In contrast to (b), the ARP frame part 5
The content of the source MAC address field 55 of No. 2 is MA
It is C (a). Therefore, on the receiving side of this frame, the source MAC address does not match between the MAC header portion 51 and the ARP frame portion 52. Depending on the implementation of the receiving side device, this frame may be judged to be invalid and discarded.

M of the upper module at all ports
The problem is described about the method of setting the AC address in the source MAC address field of the MAC header.

According to this method, in the case of the configuration of FIG. 4, the M of the upper module 44 in all the ports 42b to 42x.
AC address; MAC (a) will be set in the source MAC address field 54. However, the interface module 43 is the M of the upper module 44.
In order to set the AC address in the source MAC address field, the interface module 43 must be provided with an interface for acquiring the MAC address of the upper module 44. Therefore, the software becomes complicated. And this software reduces the independence between modules.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, to provide a module mounting method for a switching hub which enhances the independence of modules and simplifies the processing in the interface module.

[0016]

In order to achieve the above-mentioned object, the present invention provides a plurality of ports connected to a network, a port interface module for these ports, and an external host above them. Upper module for communication and source MAC of received frame
A switching hub that learns an address by associating it with a port and searches for a port by the destination address of a received frame, and in a switching hub that relays frames between ports, the interface module for communicating with its upper module A virtual port is provided, and this virtual port is also MAC based on the above filtering database like other ports.
It learns and searches for addresses and relays frames.

The upper module sets the MAC address assigned to the upper module in the source address field of the MAC header portion of the frame to set the MAC address.
The MAC frame may be assembled and transmitted to the virtual port of the interface module.

The MAC address of the virtual port of the interface module and the MAC of its upper module
The address may be the same.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The gist of the present invention is to provide a virtual port between a switching hub interface module and a host module such as ARP or IP, and treat the virtual port as if it were any other network port. The purpose is to simplify the processing of the interface module by exchanging data with the upper module via the virtual port.

FIG. 1 shows a module configuration of a switching hub as an embodiment of the present invention. As illustrated, the switching hub 1 has a plurality of ports connected to a network; network ports 2b, 2c, ..., 2x,
A port interface module 3 for these ports, a host module 4 above it for communicating with external hosts, and a source MAC of the received frame
A filtering database (not shown) that learns an address by associating it with a port and searches for the port by the destination address of the received frame. The upper module 4 is
It includes an IP module and an ARP module.

The interface module 3 is provided with a virtual port for communicating with an upper module; a virtual port 2a. Virtual port 2a is network port 2
It has the same function as b-2x. That is, the frame from the upper module 4 can be received, and the frame relayed by the network port 3 can be transmitted to the upper module 4. Further, the interface module 3 can also learn and search the MAC address by the filtering database for the virtual port 2a as in the case of the network ports 2b to 2x and relay the frame.

The interface module 3 uses the MAC address of the virtual port 2a; MAC (a1) and the MAC addresses of the network ports 2b-2x; MAC.
(B), MAC (c), MAC (d), ..., MAC
The upper module 4 recognizes each of (x) and the IP address; A and the MAC address; MAC (a).

The upper module 4 sets its own MAC address in the transmission MAC address field of the MAC header and assembles a complete MAC frame, and then completes the complete MA frame.
The C frame can be transmitted to the virtual port 2a of the interface module 3.

The interface module 3 can receive the frame from the virtual port 2a, learn the source MAC address of the MAC header, and register it in the filtering database. Also, it is possible to search the filtering database and relay the frame to another port. Conversely, network port 2b-
Upon receiving a frame from 2x, the filtering database allows the frame to be relayed to virtual port 2a just like any other network port.

The operation of the switching hub 1 will be described using an example in which the ARP module communicates with the outside. The format of the frame at this time is shown in FIG. As shown, the address portion of the ARP frame is divided into a MAC header portion 21 and an ARP frame portion 22.
The C header part 21 has a destination MAC address field 2
3 and a source MAC address field 24,
The RP frame portion 22 has a source MAC address field 25, a source IP address field 26, a MAC address field 27 of a partner seeking, and a MAC address field 28 of a partner looking for. AR
P module is the MAC address of upper module 4; M
AC (a) is set in the source MAC address field 24 of the MAC header and the broadcast address is set to MA.
It is set in the destination address field of the C header 21 and transmitted to the virtual port 2a of the interface module 3.

When the virtual port 2a of the interface module 3 receives this frame, it performs the same processing as other network ports. First, the source MAC address of the MAC header is learned, and the entry MAC (a) || port 2a is recorded in the filtering database. Next, since the destination MAC address is the broadcast address, the frame is relayed to all the ports 2b to 2x other than the virtual port 2a. Since the management host is on the network connected to any network port, it can receive ARP. This management host sends an ARP response. This ARP response is M
The destination address of the AC header is the MAC address of the upper module; MAC (a).

Next, the interface module 3
ARP from management host to any network port
Response, the destination address of the MAC header is the MAC address of the upper module; MAC (a), so it is found that the relay destination port is the virtual port 2a by searching the filtering database. , This frame is relayed to the virtual port 2a.

Next, another embodiment will be described.

As shown in FIG. 3, the switching hub 1 has network ports 2b,
2c, ..., 2x, a port interface module 3, an upper module 4, and a filtering database (not shown). However, the MAC address of the virtual port 2a is MAC (a). This is the same as the MAC address of the upper module; MAC (a). Since the virtual port 2a is not visible from the outside in this way, the MAC address of the upper module; MAC (a) may be used. This saves one MAC address.

The upper module 4 has a virtual port 2a.
MAC (a) ‖ port 2 because it is fixedly connected to
The entry of a can be set in the filtering database as a static static entry. If it is a static entry, that entry will not be deleted due to timeout, and the interface module can always refer to it, and the increase in traffic due to relaying all ports to search for MAC (a) can be suppressed.

[0031]

The present invention exhibits the following excellent effects.

(1) Since the interface module is provided with a virtual port for communicating with the host module, the interface module exchanges data with the host module via the virtual port, and the independence of the module is maintained. To be enhanced.

(2) Since the virtual port can be treated in the same way as the network port, the interface module of the switching hub can directly use the function of processing the received frame of the network port when processing the frame from the upper module. Therefore, the processing of the interface module can be simply realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a module configuration of a switching hub according to the present invention.

FIG. 2 is a frame configuration diagram showing an address portion of a frame transmitted by an ARP module of a switching hub according to the present invention to an interface module.

FIG. 3 is a configuration diagram showing a module configuration of a switching hub according to the present invention.

FIG. 4 is a configuration diagram showing a module configuration of a conventional switching hub.

FIG. 5 is a frame configuration diagram showing an address portion of an ARP frame transmitted from an interface module of a conventional switching hub.

[Explanation of symbols]

1 switching hub 2a virtual ports 2b, 2c, ..., 2x network port 3 interface module 4 upper module 21 MAC header part 22 ARP frame part 24 source MAC address field of MAC header part 25 source of ARP frame part MAC address field

Claims (3)

[Claims] 1. A plurality of ports connected to a network, a port interface module for these ports, a host module above them for communicating with an external host, and a source MAC of a received frame.
A switching hub that learns an address by associating it with a port and searches for a port by the destination address of a received frame, and in a switching hub that relays frames between ports, the interface module for communicating with its upper module A virtual port is provided, and this virtual port is also MAC based on the above filtering database like other ports.
A switching hub module implementation method that learns and searches addresses and relays frames. 2. The upper module uses the MAC address assigned to the upper module as the MAC of a frame.
MA in the sender address field of the header part
4. The switching hub module mounting method according to claim 1, wherein a C frame is assembled and the MAC frame is transmitted to a virtual port of the interface module. 3. The MAC address of the virtual port of the interface module and the MA of its upper module
The switching hub module mounting method according to claim 1, wherein the C address is the same as the C address.