JP3132426B2 - High-speed LAN switching control method and system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-speed switching method for a LAN switch system and an LA to which the method is applied.
N high speed switching system.

[0002]

2. Description of the Related Art ARP control and switching control in a conventional LAN switch system will be described.

FIG. 6 is a schematic diagram of a conventional LAN switch system. A LAN switch 30 for accommodating LAN1 to LANn in ports _{1 to n} as a plurality of LANs;
N is connected to the terminal 40 (terminal 1 to terminal n). The IP address of terminal 1 is IP ₁ , the MAC address is AAA, the terminal 2. The the IP address IP2, MAC address BBB, IP _n the IP address of the terminal n, MA
The C address is NNN.

[0004] First, a case where a communication request from the terminal 1 to the terminal 2 occurs in the ARP control will be described. IP from upper application 11 of terminal 1 to partner terminal 2
When the packet is output, the ARP client 12 transmits the MAC address BB corresponding to the IP address IP2 of the terminal 2
A search is performed to determine whether or not B is recognized. If the B is not recognized (if it is recognized, a packet with the communication partner terminal address (hereinafter, referred to as DA) as BBB is transmitted), the MAC address corresponding to IP2 is notified. Request (ARP request)
Using a broadcast packet. Broadcast packets are all LAN
Since all the terminals receive this ARP request and only the terminal 2 corresponding to the IP address IP2 is sent to the port,
It returns its own MAC address information BBB to the source terminal 1. In this way, the terminal 1 can recognize the MAC address of the terminal 2 and transmit a packet.

[0005] IEEE80 known by the name of Ethernet
In the 2.3 LAN, the MAC address has a 48-bit configuration, and there are two types of global addresses that are used and managed worldwide and user-definable local addresses. Addresses are commonly used.

Next, the operation of the conventional LAN switch when the terminal 1 sends a packet to the terminal 2 will be described.

In communication from the terminal 1 to the terminal 2, a packet in which the DA of the packet is BBB is transmitted from the terminal 1 to the LAN1. The LAN switch 30 receives the packet from the port ₁ that accommodates the LAN ₁ and searches the routing table 33 for the destination LAN port by looking at the DA of the packet. The routing table 33 is a global MAC
A memory for searching for a port number using a 48-bit address as a search key, and a content addressable memory (Content A)
addressable Memory, hereinafter referred to as CAM). In this case, the accommodation port number 2 of the BBB is searched. The switch control unit 3 having received the notification of the destination port number of the packet from the routing table 33
4 sends a packet to port 2 in which the terminal having the MAC address BBB is accommodated. In this way, packet switching is controlled.

[0008]

The above-mentioned conventional LAN
The switch is Rute queuing table for determining the delivery destination of the packet received by the LAN switch, even though the number of terminals managed simultaneously in LAN switch system is much less than 2 ^48, MAC addresses of 48 bits Switching is performed by searching the port number from. Although the routing table is realized by the memory or CAM,, in the case of the memory it must be searched unique MAC address 48 bits of space, 2 ⁴⁸ search process packet processing switching it takes time for Tsuri There is a problem that ability is not improved.

As a method of searching a memory at high speed, there is a method of using a plurality of memories to set a memory address to 48 bits and directly mapping a MAC address to be searched to a memory address. And the consumption current increases. On the other hand, the CAM can perform a high-speed search as compared with the memory, but has a disadvantage that the cost is high.

An object of the present invention is to provide a high-speed LAN switching method with improved handling of global MAC addresses.

[0011]

SUMMARY OF THE INVENTION A high-speed LAN switching method according to the present invention accommodates a plurality of LANs and transmits the first LAN from a first terminal connected to the accommodated first LAN.
Communication to a second terminal connected to a second LAN different from the first LAN is determined based on the destination MAC address of the packet transmitted from the first terminal, and the destination terminal to which the packet is to be transmitted is determined. In a high-speed LAN switching control method in a LAN switching system having a LAN switch that transmits a packet only to a connected LAN, each terminal can be identified to a maximum number of terminals in the system corresponding to a global MAC address. A local MAC address configured to be compressed to the number of bits that can be assigned is assigned.

At the time of calling, each terminal makes an inquiry to the LAN switch for the local MAC address of the communication partner terminal which is not held in the terminal itself, by presenting the IP address which is the in-system identification address of the partner terminal.

The LAN switch has a management table describing a local MAC address, a global MAC address, and a connection port corresponding to each IP address, and searches the management table for a local MAC address corresponding to the input IP address. The detection result is notified to the inquiry source, and the detected global MAC address and LAN port information are stored as the IP address corresponding data.

Thereafter, when a packet addressed to the local MAC address is input from a terminal, the terminal is switched to a corresponding connection port stored therein, and a corresponding global MA is connected.
Transfer to C address.

The local MAC of the communication partner terminal
Pseudo ARP where address inquiry includes IP address
By sending a packet, a search of the management table of the LAN switch is performed by a pseudo ARP server,
The local MAC address detected by the pseudo ARP server is notified to the requesting terminal, and the storage of the IP address corresponding data is stored in a routing table memory. When a packet addressed to the local MAC address is input, the switch control unit The routing table memory is searched at high speed and the input packet is stored in the corresponding LA.
2. The high-speed LAN switching control method according to claim 1, wherein the connection is switched to an N port, and the data is transferred to a global MAC address.

The high-speed LAN switching system of the present invention accommodates a plurality of LANs, and accommodates the first LAN accommodated therein.
From a first terminal connected to a second terminal connected to a second LAN different from the first LAN,
An LA that determines a destination MAC address of a packet transmitted from the first terminal and transmits the packet only to the LAN to which the destination terminal to which the packet is to be transmitted is connected
In a high-speed LAN switching system having N switches, each terminal is assigned a local MAC address corresponding to a global MAC address and compressed to a number of bits identifiably given to the maximum number of terminals in the system.

An AR which issues a request for notification of a local MAC address of a communication partner terminal to each terminal at the start of packet communication.
The LAN switch has a pseudo ARP client unit that sends out the P request as a pseudo ARP packet including an IP address presentation that is an address in the system of the communication partner terminal.
C address, accommodation LAN port number, and local M
It has a management table for managing AC addresses, and upon receiving the pseudo ARP packet, searches the management table to detect both MAC addresses and the port number of the accommodated LAN, and sends a response notification of the local MAC address. A pseudo ARP server that stores the global MAC address detected at the same time and the accommodated LAN port information as data in a routing table memory using the local MAC address as an address. When a packet having an address is sent, a LAN port of a packet transfer destination and a global MAC address are read from the routing table memory at high speed from the routing table memory, and the input packet is connected to a corresponding LAN port. To A switch control unit that transfers the Baru MAC address.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a high-speed LAN switching system according to the present invention. LAN ₁ to LAN
LAN switch 20 for accommodating LAN _n in ports ₁ to n
And the terminal 10 (terminal 1 to terminal n) connected to each LAM
Is a LAN switch system configured from the host application 11 to the communication partner terminal.
M corresponding to the IP address when the P packet is sent out
ARP client 1 that inquires about AC address
2 has a pseudo ARP client 13 which converts an ARP request into a pseudo ARP packet and sends it out. LA
The N switch 20 includes a pseudo ARP server 21 for resolving an address search request based on the pseudo ARP packet, a routing table memory 23 for searching a port for transmitting a packet received from the accommodation LAN, and a switch control unit for switching the packet. 24.

Next, the operation of the present invention will be described in detail with reference to the sequence chart of FIG. IP address of terminal 1 is IP ₁ , global MAC address is AAA, terminal 2
The IP address of the terminal n is IP ₂ , the global MAC address is BBB, and the IP address of the terminal n is the IP address I
P _n , the global MAC address is NNN, and the total number of MAC addresses managed simultaneously in the system is 8196 (2
¹³ ).

First, a local MAC address having fewer effective bits than a global address using only the number of effective bits that can represent the maximum number of terminals managed in the system is assigned to each terminal.

Next, ARP control will be described. Now, when communicating from the terminal 1 to the terminal 2, first, the upper application 11 of the terminal 1 sends an IP packet for the terminal 2 to the ARP client 12 (FIG. 2). ARP client 12 receives the IP packet transmitted from the upper application 11, transmits Te requested a whether the adjustment base or local MAC address is held corresponding to the IP address IP ₂ of the terminal 2 is, no (if there is 2), I
A search request (ARP request) for the MAC address corresponding to P ₂ is transmitted (FIG. 2).

Here, the pseudo ARP client 1 in the terminal
Reference numeral 3 denotes a pseudo ARP server 21 in the LAN switch 20 which transmits an ARP request sent from the ARP client 12.
Is converted to a pseudo-ARP packet that makes an address resolution request to (FIG. 2).

[0023] Pseudo ARP server 21 which has received the pseudo ARP packet, local MA corresponding to the requested IP ₂
The C address is searched in the IP-MAC correspondence table 22 (of FIG. 2).

The IP-MAC correspondence table 22 contains an IP
The local MAC address corresponding to the address, the global MAC address, and the LA
N port numbers are stored. FIG. 3 shows an example of the IP-MAC correspondence table 22.

With regard to IP ₂ which is a search key from the pseudo ARP server 21, the global MAC address BBB
, Accommodation port number 2, and local MAC address bb
b is detected from the IP-MAC correspondence table 22 (of FIG. 2). The MAC address bbb is composed of the necessary minimum number of bits that can uniquely represent the total number of MACs controlled by the LAN switch 20, and all other bits are "0". As shown in FIG. 4, the total number of simultaneously managed MAC addresses in the system of this embodiment is 819.
When 6 (2 ¹³ ) is used, 13 bits out of 48 bits of the MAC address can be uniquely managed in the system. IP-MAC correspondence table 22
AR obtained information (BBB, port 2, bbb) from
The P server 21 returns the local MAC address bbb to the terminal 1 as a response to the pseudo ARP packet (of FIG. 2), and stores the local MAC address bbb in the routing table memory 23 in the LAN switch 20.
bb and the corresponding global MAC address BBB and accommodation port number 2 are stored (FIG. 2).

As shown in FIG. 5, the routing table 23 can be constituted by a general-purpose inexpensive memory using the notified local MAC address bbb as a memory address, and using the global MAC address BBB and the accommodation port number as data.

In the terminal 1 receiving the response packet from the pseudo ARP server 21, the pseudo ARP client 13
The response packet is converted into a response packet from the terminal that has made the ARP request, and is notified to the ARP client 12 (FIG. 2). Local M of partner terminal 2 to communicate with
The ARP client 12 having received the AC address bbb transmits the destination address of the IP packet transmitted from the upper application 11 as bbb (FIG. 2), thereby enabling communication.

Next, the packet switching control of the LAN switch 20 will be described. The ARP client 12 of the terminal 1 that has recognized the MAC address bbb of the communication partner terminal 2 by the ARP control sends a packet with DA as bbb to the LAN ₁ (FIG. 2). Switch control unit 24 of LAN switch 20 that has received a packet from LAN ₁
Extracts DAbbb of the received packet, and searches the routing table memory 23 for a transmission port and global MAC address corresponding to bbb (α in FIG. 2). Since the search information is stored in the memory having the address bbb, the switch control unit 24 can quickly search for the port number 2 and the global MAC address BBB corresponding to bbb (β in FIG. 2). Packet sending port and global MA
The switch control unit 24 having searched the C address converts the DA of the packet received from the LAN ₁ into the local MAC address b.
bb is converted to the global MAC address BBB, and the packet is transmitted to the LAN ₂ in which the terminal 2 of the global MAC address BBB is accommodated (γ in FIG. 2), thereby switching the packet.

[0029]

As described above, in the LAN switch system, the terminal side receives the ARP request for notifying the MAC address of the communication partner terminal at the start of packet communication, converts the ARP request into a pseudo ARP packet, and sends out the pseudo ARP packet. The ARP client unit and the LAN switch receive the pseudo ARP packet and receive an IP address and the IP address.
Global MAC address corresponding to address and accommodation L
It has a management table for managing an AN port number and a local MAC address, a pseudo-ARP server for notifying the local MAC address as a response, and a local MAC address notified from the pseudo-ARP server to the terminal as an address. MAC address and accommodation LA
When a packet having a local MAC address as DA is transmitted from a terminal and a routing table memory storing N port information, a packet transmission port and a global MAC address are searched from the routing table memory at high speed. By having a switch control unit that converts a DA local MAC address to a global MAC address and sends out a packet to a LAN port to which a terminal of the address is connected, high-speed switching of the LAN can be performed and very few bits There is an effect that transmission and reception of signals by numbers, data processing, and cost saving of the corresponding memory can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a LAN switch system according to the present invention.

FIG. 2 is an operation sequence chart of a high-speed LAN switching system to which the high-speed LAN switching method of the present invention is applied.

FIG. 3 is a diagram showing an example of an IP-MAC correspondence table.

FIG. 4 is an explanatory diagram showing an example of a local MAC address.

FIG. 5 shows an example of a routing table.

FIG. 6 is a block diagram of a conventional LAN switch system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Terminal 11 Upper application 12 ARP client 13 Pseudo ARP client 20 LAN switch 21 Pseudo ARP server 22 IP-MAC correspondence table 23 Routing table 24 Switch control unit 40 Terminal 30 LAN switch 33 Routing table 34 Switch control unit

Continuation of the front page (56) References JP-A-10-9614 (JP, A) JP-A-4-21066 (JP, A) JP-A-3-54973 (JP, A) IEEE Std 802.3, 1998 Edition , "2. Media Access Control (MAC) service specificion", pages. 31-35 (58) Field surveyed (Int. Cl. ⁷ , DB name) H04L 12/46 H04L 12/28 JICST file (JOIS)

Claims (3)

(57) [Claims] 1. A first terminal which accommodates a plurality of LANs and which is connected to the accommodated first LAN by a first terminal.
The communication to the second terminal connected to the second LAN different from the AN is determined based on the destination MAC address of the packet transmitted from the first terminal, and the destination terminal to which the packet is to be transmitted is connected. A high-speed LAN switching control method in a LAN switching system having a LAN switch that sends out a packet only to a LAN that has been set, wherein each terminal corresponds to a global MAC address.
In the system, a local MAC address configured by compressing the number of bits that can be identifiably added to the maximum number of terminals is assigned. The LAN switch is queried by presenting an IP address that is an intra-system identification address. The LAN switch includes a management table that describes a local MAC address, a global MAC address, and a connection port corresponding to each IP address. IP
The management table is searched for the local MAC address corresponding to the address, the detection result is notified to the inquiry source, and the simultaneously detected global MAC address and LAN
Storing port information as the IP address corresponding data, and when a packet addressed to the local MAC address is input from a terminal, exchanges connection with the stored corresponding connection port and transfers to a corresponding global MAC address. And a high-speed LAN switching control method. 2. A query of a local MAC address of the communication partner terminal is performed by sending a pseudo ARP packet including an IP address, and a search of a management table of the LAN switch is performed by a pseudo ARP.
Performed by the server, notifies the requesting terminal of the local MAC address detected by the pseudo-ARP server, stores the IP address correspondence data in a routing table memory, and inputs a packet addressed to the local MAC address. And the switch control unit searches the routing table memory at a high speed and finds an input packet corresponding to L
2. The high-speed LAN switching control method according to claim 1, wherein the connection is switched to an AN port and the data is transferred to a global MAC address. 3. A plurality of LANs are accommodated, and a first terminal connected to the accommodated first LAN transmits said first LA.
N, a communication to a second terminal connected to a second LAN different from N is determined based on a destination MAC address of a packet transmitted from the first terminal, and a destination terminal to which the packet is to be transmitted is connected. In a high-speed LAN switching system having a LAN switch that sends a packet only to a LAN, each terminal is configured by compressing the number of bits corresponding to a global MAC address to the maximum number of terminals in the system so as to be identifiable. A local MAC address assigned to the terminal is sent to each terminal, and at the start of packet communication, an ARP request for requesting a notification of the local MAC address of the terminal of the communication partner is sent to the pseudo terminal including the presentation of the IP address which is an address in the system of the terminal of the communication partner. Pseudo-A sent as ARP packet
The LAN switch includes a management table for managing a global MAC address corresponding to the IP address of each terminal, a port number of the accommodated LAN, and a local MAC address. The management table is searched to detect both MAC addresses and the port number of the accommodating LAN, notify the local MAC address as a response, use the local MAC address as an address, and simultaneously detect the global MAC address and the accommodating LAN port. A pseudo-ARP server that stores information and data as data in a routing table memory; and a terminal that receives a packet having a mouth MAC address as a communication partner terminal address. global High-speed LAN switching system characterized by having a switch control unit that transfers the global MAC address to connect to the AC address inputted read at high speed from the routing table memory packets to the corresponding LAN port, corresponding.