KR20050054003A - System and method for switching data between virtual local area networks included in same ip subnet - Google Patents

Abstract

Disclosed are a data switching system and method between different virtual local area networks that are included in the same IP subnet. The data switching system according to the present invention analyzes a switch for receiving and processing an ARP request packet requesting an identifier of a destination node from a source node, and analyzes the received ARP request packet so that the source node and the destination node are not included in the same IP subnet. In a case where it is determined that the IP switching module, the source node, and the destination node belong to different virtual local area networks included in the same IP subnet to apply data to the destination node by applying a general IP switching / routing technique, the identifier of the destination node is determined. A local ARP module for acquiring, updating a local ARP table using the obtained destination node identifier, and generating and transmitting an ARP response packet using the identifier of the switching system. According to the present invention, data can be switched without mapping different virtual local area networks included in the same IP subnet to different IP subnets.

Description

System and method for switching data between virtual local area networks included in same IP subnet}

The present invention relates to a data packet transmission and reception technique, and more particularly, to a data switching system and method between virtual local area networks belonging to the same IP subnet.

Every host that connects to a network, such as the Internet, has a 32-bit Internet Protocol (IP) address that corresponds to a network layer address. In addition, when a host is connected to a local area network (LAN), an interface (such as a LAN card) included in the host has a 48-bit MAC address (media access control address) necessary for exchanging data packets. These MAC addresses are used to physically transfer frames between hosts within the LAN. In addition, IP addresses are used to process functions of the Internet layer (connectionless datagram delivery service, routing, etc.) for IP packets in the forwarded data packets.

In order to physically deliver an IP packet to a computer in a local area network, it must first know the MAC address of its destination host. In this way, a protocol for determining the MAC address of a device with an IP address of a host is called an address resolution protocol (ARP).

However, it is advantageous in various ways to integrate and manage a plurality of hosts or nodes on a network into a single virtual local area network (VLAN). In other words, VLAN refers to configuring a group by dividing a plurality of nodes into logical LAN segments (broadcast domains) regardless of the geographical location of network nodes. By configuring a virtual local area network, you can reduce the size of the broadcast domain by separating the resources and users on the network into different workgroups. In addition, since the size of the broadcast domain is reduced, the amount of traffic (traffic) between segments can be reduced, and the network security can be improved by proposing the use of network resources. In addition, by configuring the virtual local area network has the advantage that the nodes can be changed more easily than the physical local area network.

There are several ways to configure a virtual local area network, which is based on a port of a switch included in a virtual local area network, a MAC address of network nodes, or a user-defined IP address (IP subnet) or other protocol, that is, A virtual local area network may be configured for each application.

In the conventional virtual local area network data packet communication method, the communication between nodes on the same virtual local area network uses the same layer 2 except that it uses a virtual local area network identifier as compared to the communication between nodes on a physical LAN segment. Use bridging or layer-2 bridging. However, since the communication between virtual local area networks is logically between different local area networks, it cannot be implemented by only layer 2 bridging or switching. Currently, the virtual LAN communication technology includes a method for routing each other by assigning different IP subnets to each virtual local area network to allow communication between different IP subnets.

However, in a communication method for implementing different virtual local area networks with different IP subnets, when one subnet is to be configured with multiple virtual local area networks, it is necessary to divide the subnet into multiple subnets of fewer groups. In this process, when a new subnet is created, the network address, router address, and broadcast address of the subnet must be allocated, which is a waste of address. In addition, the configuration of each virtual local area network to a different subnet has the disadvantage that it does not fully accommodate the variety of the virtual local area network configuration method described above. For example, even if the virtual local area network is configured based on the switch's port or the MAC address of the network node, the virtual local area network should be implemented because it must always be operated in a subordinate manner to the virtual local area network configuration by the IP subnet. You can't take full advantage of it.

Therefore, there is an urgent need for a technology that allows communication between virtual local area networks in the same subnet to act as communication between different IP subnets without setting each virtual local area network to a different IP subnet for data communication between virtual local area networks. do.

SUMMARY OF THE INVENTION An object of the present invention is to provide a data switching system for enabling data communication between virtual local area networks while accommodating a variety of methods for constructing a virtual local area network.

Another object of the present invention is to provide a method for enabling data switching without mapping different virtual local area networks included in the same IP subnet to different IP subnets.

One aspect of the present invention for achieving the above object relates to a data switching system for transmitting data between nodes of one or more virtual local area networks included in the same IP subnet. According to an aspect of the present invention, a data switching system includes a switch for receiving and processing an ARP request packet for requesting an identifier of a destination node from a source node, a received ARP request packet, and analyzing the received ARP request packet on the same IP subnet. If not included, if it is determined that the IP switching module, source node and destination node for transferring data to the destination node by applying a general IP switching / routing technique belong to different virtual local area networks included in the same IP subnet, It is characterized in that it comprises a local ARP module for obtaining an identifier of, updating the local ARP table using the obtained identifier of the destination node, and generates and transmits an ARP response packet using the identifier of the switching system. In particular, the local ARP module included in the data switching system according to an aspect of the present invention may include a determination module, an ARP lookup module, a broadcast module, an ARP table update module, and a module for determining whether a source node and a destination node are included in the same virtual local area network. ARP response packet generation module. The ARP lookup module looks up the IP address of the destination node in a local ARP table that maps the IP addresses and identifiers of one or more destination nodes, unless the source and destination nodes are included in the same virtual local area network. If the IP address of the destination node does not exist in the local ARP table, the broadcast module sources the IP address and identifier of the data switching system to the virtual local area network that does not include the source node among all virtual local area networks included in the IP subnet. Generate and broadcast an ARP request packet with the node's IP address and identifier, and the ARP table update module receives the ARP response packet from the destination node and updates the local ARP table. In addition, the ARP response packet generation module generates and transmits, to the source node, an ARP response packet having the identifier of the data switching system as the destination address.

Another aspect of the present invention for achieving the above object is a method for transmitting data between nodes of one or more virtual local area networks included in the same IP subnet, the identifier of the destination node from a source node included in the virtual local area network Receiving an ARP request packet requesting a request, if the source node and the destination node is determined not to be included in the same IP subnet by analyzing the ARP request packet, to transfer data to the destination node by applying a general IP switching / routing technique If it is determined that the IP switching step, the source node and the destination node are included in the same IP subnet, obtain the identifier of the destination node, update the local ARP table using the obtained destination node identifier, Region A, which generates and sends ARP response packets And transmitting data using the RP processing step and the ARP response packet. In particular, the local ARP processing step included in the data switching method according to another aspect of the present invention may include determining whether the source node and the destination node are included in the same virtual local area network, and mapping IP addresses and identifiers of one or more destination nodes. Lookup of the destination node's IP address, if the destination node's IP address does not exist in the local ARP table, the virtual local area network that does not include the source node among all virtual local area network switches included in the subnet. Generating and broadcasting, at the switch, an ARP request packet having the IP address and identifier of the switch of the virtual local area network including the source node as the IP address and identifier of the source node, receiving the ARP response packet from the destination node, As a source node and steps for updating the ARP table, include the source node. An identifier of the virtual local area network switch comprises the step of generating and transmitting the ARP response packet to the destination address. Preferably, in the data switching method and system according to the present invention, the identifier of the destination node is one of a MAC address of the destination node or a port number assigned to the destination node. In addition, the local ARP process according to the present invention is characterized in that it is automatically performed or selectively performed by the user's selection.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. For each figure, like reference numerals denote like elements.

1 is a block diagram illustrating an embodiment of a data switching system between virtual local area networks according to an aspect of the present invention. As shown in FIG. 1, the L2 switch 160 communicates data packets between Node A 175 and Node B 185 included in each of the first virtual local area network 170 and the second virtual local area network 180. In charge of. The router 150 shown in FIG. 1 includes an IP switching module 120 and a proxy ARP module 130. In FIG. 1, proxy ARP module 130 includes local ARP module 140. The router 150 transmits and receives data from a broadband communication network such as the Internet 110.

Node A 175 and Node B 185 may be hosts or network terminals. The L2 switch 160 may perform a layer 2 function, and the router 150 may be an L2 / L3 switch performing a layer 2 / layer 3 function, an L3 switch performing an L3 function, or an L3 router. In the present specification, for the sake of simplicity, all devices that perform functions of a switch or a router are collectively referred to as a 'router'. When the router 150 wants to transmit an IP packet from one subnet to another subnet, the router 150 transmits the packet through the IP switching module 120. That is, the IP switching module 120 is responsible for data communication between different subnets. In addition, the router 150 may include a proxy ARP module 130 that responds with its MAC address when the source node requests a MAC address for the IP address of the destination node. That is, the proxy ARP module 130 is an apparatus for obtaining an identifier, such as the MAC address of the destination node, from the IP address of the destination node, and operates according to the address resolution protocol technique according to the prior art.

In FIG. 1, the proxy ARP module 130 includes a local ARP module 140 for performing communication between virtual local area networks within the same IP subnet. Operation of the local ARP module 140 will now be described in detail.

The proxy ARP module 130 according to the prior art regards the communication between the same subnets when the IP subnet mapped to the logical interface receiving the source node's IP address or ARP request packet and the destination node's IP address are identical. Do not generate a response packet. On the other hand, the local ARP module 140 according to the present invention operates even when the source and destination nodes have the same IP subnet, that is, communication between two virtual local area networks belonging to the same IP subnet. First, the local ARP module 140 according to the present invention transmits the ARP request packet to all nodes belonging to the IP subnet to obtain the MAC address of the destination node. At this time, the source node address of the ARP request packet is changed to the address of the router 150 and transmitted. After storing the obtained MAC address in a local ARP table (not shown), a response packet is transmitted to the source node using the MAC address of the router 150 as the MAC address of the destination node. Therefore, communication between virtual local area networks belonging to the same IP subnet is possible using the local ARP table.

In this case, since the router 150 according to the present invention includes the local ARP module 140, communication between different virtual local area networks on the same subnet is possible. Therefore, it is not necessary to map the virtual local area network to different subnets as in the prior art, thereby reducing the waste of IP addresses. In addition, when the virtual local area network is configured based on the switch's port or the MAC address of the network node, the virtual local area does not need to be coupled to operate in the virtual local area network configuration by the IP subnet as in the prior art. You can take full advantage of the benefits of implementing a network.

The identifier of the destination node stored in the local ARP table may be a MAC address or a port number of the L2 switch 160. In addition, the operation of the local ARP module 140 may be implemented to be selectively performed by the user. When the user disables the operation of the local ARP module 140, the proxy ARP module 130 operates in the same manner as the ARP processing module according to the prior art, and thus can be easily implemented in various devices.

Additional configuration and operation of the local ARP module 140 will be described later in detail using FIG. 3.

2 is a flowchart illustrating a data switching method between virtual local area networks according to another aspect of the present invention.

In FIG. 2, when a source node (eg, node A of FIG. 1) wants to send a packet to a destination node (eg, node B of FIG. 1), an identifier of the destination node is needed first, and thus an ARP request packet is generated. Receive (S210). As described above, the identifier of the destination node may be the MAC address of the destination node. When the ARP request packet is received, it is determined whether the source node and the destination node are included in the same IP subnet (S230). In this case, if the source node and the destination node are not included in the same IP subnet, the proxy ARP module according to the prior art (for example, the proxy ARP module of FIG. 1) is operated (S270). Therefore, packet switching through IP routing is performed by a general proxy ARP function. On the other hand, if it is determined in step S230 that the source node and the destination node are included in the same IP subnet, the source node transmits the ARP request packet to the switch (L2 switch of FIG. 1) of the virtual local area network to which it belongs. Unlike the prior art, the virtual local area network router (router of FIG. 1) receiving the ARP request packet operates the local ARP module (S250).

FIG. 3 is a flowchart for describing a local ARP processing step of the switching method illustrated in FIG. 2 in detail.

The local ARP module first compares whether the virtual local area network of the source node and the destination node is the same (S310). As a result of the comparison, when the source node and the destination node are included in the same virtual local area network, the ARP request packet is ignored and no function is performed (S370). On the other hand, if the virtual local area network of the source node and the destination node is different from each other, it is determined whether the destination IP address exists in the local ARP table (S320), and the local ARP table stores information in which the destination node's IP address and identifier are mapped. do. If the IP address of the destination node already exists in the local ARP table, the ARP response packet is transmitted to the source node by setting the destination MAC address as the address of the virtual local area network router (S350). However, if the destination IP address does not exist in the local ARP table, the ARP request packet is broadcast to a local area network that does not include a source node among all other virtual local area networks included in the same subnet (S330). At this time, the router according to the present invention generates and transmits an ARP request packet in which the source node's IP and MAC addresses are set to its own IP address and MAC address). Then, the destination node receiving the ARP request packet from the router transmits an ARP response packet including its MAC address to the router. When the router receives the ARP response packet from the destination node, the router stores it in the local ARP table (S340). In addition, the ARP response packet having the MAC address of the router as the destination identifier is transmitted to the source node (S350). The transmission of the ARP response packet to the source node (S350) may be performed before the ARP procedures S330 and S340 to other virtual local area networks. As such, when the local ARP table is updated, all packets transmitted from the source node to the destination node are transmitted and received using the updated local ARP table.

Therefore, a local proxy ARP function is implemented in response to an ARP request for an IP address included in a corresponding subnet category in a router performing routing between virtual local area networks included in the same IP subnet.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. For example, it is apparent that the local ARP module according to the present invention is not necessarily included in the proxy ARP module, and can operate independently and can be activated and deactivated by the user's selection.

Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to the present invention, a data switching system for adding a local proxy ARP function to a router enables communication between multiple virtual local area networks on the same subnet.

In addition, according to the present invention, it is not necessary to map each virtual local area network to a different subnet, thereby reducing the waste of IP addresses, and in configuring the virtual local area network, it can be configured in various ways without being dependent on the IP subnet. A data switching method is provided.

1 is a block diagram illustrating an embodiment of a data switching system between virtual local area networks according to an aspect of the present invention.

2 is a flowchart illustrating a data switching method between virtual local area networks according to another aspect of the present invention.

FIG. 3 is a flowchart for describing a local ARP processing step of the switching method illustrated in FIG. 2 in detail.

Claims (8)

A data switching system for transmitting data between nodes of one or more virtual local area networks included in the same IP subnet, A switch for receiving and processing an Address Resolution Protocol (ARP) request packet requesting an identifier of a destination node from a source node; An IP switching module for analyzing the received ARP request packet and transferring data to the destination node by applying a general IP switching / routing technique when the source node and the destination node are not included in the same IP subnet; If it is determined that the source node and the destination node belong to different virtual local area networks included in the same IP subnet, the identifier of the destination node is obtained, and the obtained identifier of the destination node is an IP address and an identifier of one or more destination nodes. And a local ARP module for generating and transmitting an ARP response packet by using the identifier of the switching system. The method of claim 1, wherein the local ARP module, A determination module for determining whether the source node and the destination node are included in the same virtual local area network; An ARP lookup module for looking up an IP address of the destination node in the local ARP table if the source node and the destination node are not included in the same virtual local area network; If the IP address of the destination node does not exist in the local ARP table, the IP address and identifier of the data switching system are sourced to a virtual local area network that does not include the source node among all virtual local area networks included in the subnet. A broadcast module for generating and broadcasting an ARP request packet having an IP address and an identifier of the node; An ARP table updating module which receives an ARP response packet from the destination node and updates the local ARP table; And And an ARP response packet generation module for generating and transmitting, to the source node, an ARP response packet having an identifier of the data switching system as a destination address. The method according to claim 1 or 2, And the identifier of the destination node is one of a MAC address of the destination node or a port number assigned to the destination node. The method of claim 3, wherein the local ARP module, Data switching system between virtual local area networks belonging to the same IP subnet, characterized in that it is automatically operated or selectively operated by the user's selection. In the data transmission method between the nodes of one or more virtual local area network included in the same IP subnet, Receiving an address resolution protocol (hereinafter referred to as "ARP") request packet for requesting an identifier of a destination node from a source node included in the virtual local area network; If the source node and the destination node are not determined to be included in the same IP subnet by analyzing the ARP request packet, an IP switching step for transferring data to the destination node by applying a general IP switching / routing technique; If it is determined that the source node and the destination node is included in the same IP subnet, the local ARP table to obtain the identifier of the destination node, to map the obtained identifier of the destination node to the IP address and the identifier of one or more destination node A local ARP processing step for generating and transmitting an ARP response packet using the identifier of the switching system; And And transmitting data using the ARP response packet. The method of claim 5, wherein the local ARP processing step, Determining whether the source node and the destination node are included in the same virtual local area network; If the source node and the destination node are included in the same virtual local area network, ignoring the ARP request packet; If the source node and the destination node are not included in the same virtual local area network, looking up the IP address of the destination node in the local ARP table; If the IP address of the destination node does not exist in the local ARP table, a virtual local area network including the source node in a virtual local area network switch that does not include the source node among all virtual local area network switches included in the subnet. Generating and broadcasting an ARP request packet having the IP address and the identifier of the switch of the source node as the IP address and the identifier of the source node; Receiving an ARP response packet from the destination node and updating the local ARP table; Generating and transmitting, to the source node, an ARP response packet having an IP address and an identifier of a switch of a virtual local area network including the source node as a destination address; And And transmitting data using the local ARP table. The method according to claim 5 or 6, The identifier of the destination node is one of the MAC address of the destination node or a port number assigned to the destination node, the data transmission method between virtual local area networks belonging to the same IP subnet. The method of claim 7, wherein the local ARP processing step, Method of transmitting data between virtual local area networks belonging to the same IP subnet, characterized in that performed automatically or selectively performed by a user's selection.