KR101415978B1 - System and method for configurating and managing dhcp server of a subnet in a data transfer apparatus using virtual lan - Google Patents

Abstract

The present invention relates to a system and method for setting and operating a DHCP server in a subnet in a data transmission apparatus using a virtual LAN. According to one aspect of the present invention, there is provided a communication system including: a CPU having one Ethernet MAC; An L2 Ethernet switch having one physical CPU port connected to the Ethernet MAC, an external network port connected to the external network, and an internal network port connected to the internal network; A first VLAN group including a physical CPU port and an external network port of the CPU and the L2 Ethernet switch and a second VLAN group including a physical CPU port and an internal network port of the CPU and the L2 Ethernet switch Wherein the CPU of the first VLAN group operates as a DHCP client with respect to the external network and the CPU of the second VLAN group operates with respect to the internal network as a DHCP server. A DHCP server configuration and operation system is proposed.

Description

TECHNICAL FIELD [0001] The present invention relates to a system and method for configuring and operating a subnetwork DCS server in a data transmission apparatus using a virtual LAN,

The present invention relates to a system and method for setting and operating a DHCP server in a subnet in a data transmission apparatus using a virtual LAN.

Specifically, in a data transmission apparatus having an L2 Ethernet switch connected through a single physical port to a CPU having one Ethernet MAC, a virtual LAN is formed to divide a virtual LAN group between an internal network and an external network, And more particularly, to a system and method for setting and operating a DHCP server in a subnet in a data transmission apparatus using a virtual LAN.

A Virtual Local Area Network (VLAN) is a technology that allows a set of end stations on several physically separated LAN segments to communicate as if they belonged to one common LAN, regardless of their physical location. It says. This VLAN technology allows a single Ethernet switch to be used as if it were several separate switches, and the devices connected to one Ethernet switch can also have different broadcast domains, Can be separated. Therefore, these VLANs limit the area where the broadcast and multicast traffic of the existing LAN is carried, thereby reducing bandwidth waste and increasing the efficiency of the entire network. VLANs also enhance network security by creating virtual boundaries and transferring data to only the desired groups.

In a switch system with VLAN capability, the Ethernet Layer 2 (L2) switching function constructs a forwarding table to determine the forwarding of input frames by the learning process. The forwarding table of the L2 switch generally consists of elements such as MAC (Media Access Control) address, VLAN (Virtual LAN) ID, and output port. After the forwarding table is established, the processing procedure for the input frame is determined to be the destination MAC address of the input frame, and then output to all the ports of the corresponding VLAN group excluding the input port in the case of the frame having the multicast or broadcast MAC address . In the case of a frame having a unicast MAC address, if an entry for the corresponding MAC address is included in the forwarding table, the frame is transmitted to the corresponding output port. Otherwise, the frame is flooded to all the ports.

7A and 7B relate to a subnet system in a conventional data transmission apparatus.

Referring to FIGS. 7A and 7B, when a plurality of network ports are used in a local network system in a conventional data transmission apparatus, the WAN side and the LAN side are separated by separating two switch devices as shown in FIG. 7A. Alternatively, as shown in FIG. 7B, the CPU having one switch device may have two Ethernet MACs and the L2 switch may be connected to the two Ethernet MACs, respectively, so that the first VLAN group of the WAN side and the first VLAN group of the LAN side 2 VLAN groups were formed to enable the use of multiple LAN / WAN network ports.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a data transmission apparatus having an L2 Ethernet switch connected to a CPU having one Ethernet MAC via one physical port, And to provide a system and method for allowing data transmission to be performed by dividing a virtual LAN group among external networks.

In addition, when the system operates as a DHCP server and a DHCP client in a system having a single physical port (Ethernet MAC) on the CPU, the WAN side acts as a DHCP client to the external network and the LAN side acts as a DHCP server to the internal network And a method and system for operating a DHCP server in a subnet in a data transmission apparatus using a virtual LAN.

According to one aspect of the present invention, there is provided a method of controlling a communication system including a CPU having one Ethernet MAC; An L2 Ethernet switch having one physical CPU port connected to the Ethernet MAC, an external network port connected to the external network, and an internal network port connected to the internal network; A first VLAN group including a physical CPU port and an external network port of the CPU and the L2 Ethernet switch and a second VLAN group including a physical CPU port and an internal network port of the CPU and the L2 Ethernet switch Wherein the CPU of the first VLAN group operates as a DHCP client with respect to the external network and the CPU of the second VLAN group operates with respect to the internal network as a DHCP server. A DHCP server configuration and operation system is proposed.

Preferably, according to another aspect of the present invention, when a DHCP setting message broadcast from an apparatus belonging to an external network or an internal network is received through a port of an L2 Ethernet switch, the CPU transmits a DHCP setting message frame If the port is an internal network port, the second VLAN group is operated as a DHCP server. If the port on which the DHCP setting message frame is received is an external network port, the first VLAN group is ignored and a DHCP server So as not to operate. Preferably, the DHCP setup message is a DHCP Discover or Request message.

Preferably, in accordance with another aspect of the present invention, there is provided a DHCP server setting and operating system of another data transfer apparatus in an upper network including a data transfer apparatus, a DHCP server setting and operation system of the other data transfer apparatus, When a DHCP setting message broadcast from a subnet system including a DHCP server setting and operating system of a belonging terminal device or another data transfer device and a terminal device belonging to the DHCP setting message is received, Analyzes the Ethernet address, and controls not to return a DHCP setup message response signal so as not to operate as a DHCP server for the first VLAN group. Preferably, the DHCP setup message is a DHCP Discover or Request message, and the DHCP setup message response signal is a DHCP Offer and Ack signal.

More preferably, the CPU analyzes the first half of the source Ethernet address and controls not to return the DHCP setting message response signal if the first half of the address of the Ethernet MAC or the preset value of the address of the Ethernet MAC in the system matches.

Preferably, the DHCP server setting and operating system of the subnet in the data transmitting apparatus using the virtual LAN according to another aspect of the present invention further includes a wireless communication module connected to the CPU and wirelessly connected to the internal network or the external network device, . At this time, the wireless communication module forms part of the first VLAN group when connected to the external network device, and forms part of the second VLAN group when connected to the internal network device. Also, when a DHCP setting message broadcasted from an external network or an internal network device is received through the wireless communication module, the CPU determines whether the wireless communication module is wirelessly connected to the external network device or the internal network device The second VLAN group including the wireless communication module is operated as a DHCP server, and when it is determined that the second VLAN group is connected to the external network device, the first VLAN group including the wireless communication module It is controlled not to operate as a DHCP server.

More preferably, according to another aspect of the present invention, the CPU analyzes the source address included in the received DHCP setup message frame to determine whether the wireless communication module is wirelessly connected to the external network device or the internal network device .

Preferably, according to another aspect of the present invention, when data is transmitted from an external network to an internal network, the CPU obtains a physical address of a network device of the internal network obtained from ARP (Address Resolution Protocol) communication and a routing table So that data transmission is performed between the first VLAN group and the second VLAN group.

Further, preferably, according to another aspect of the present invention, the L2 Ethernet switch uses the physical address of the internal network devices analyzed from the frame signal of ARP (Address Resolution Protocol) communication through each port to perform the L2 switch function .

In order to achieve the above object, according to another aspect of the present invention, there is provided a communication system including a first VLAN group including a physical CPU port on an L2 Ethernet switch connected to a CPU having an Ethernet MAC and an Ethernet MAC, , A CPU and a second VLAN group including a physical CPU port and an internal network port of the L2 Ethernet switch, the method comprising the steps of: (a) configuring a port of the L2 Ethernet switch Determining whether the received signal is a broadcasted DHCP setting message; (b) determining which of the external network port and the internal network port is received when the DHCP setting message is determined in the step (a); (c) if it is determined in the previous step (b) that the packet is received through the internal network port, the CPU operates as a DHCP server for the second VLAN group; And (d) if it is determined in the previous step (b) that the packet is received through the external network port, the CPU ignores the DHCP setup message and does not operate as a DHCP server for the first VLAN group; A method of setting and operating a DHCP server in a subnet in a data transmission apparatus using a virtual LAN is proposed. Preferably, the DHCP setup message is a DHCP Discover or Request message.

According to another aspect of the present invention, in the method for setting and operating the DHCP server of the subnet in the data transmission apparatus using the virtual LAN, in the step (d), the DHCP setting message received through the external network port The source Ethernet address included in the frame is analyzed to prevent the first VLAN group from acting as a DHCP server.

According to still another aspect of the present invention, the step (d) includes: (d-1) the first half of the source Ethernet address included in the DHCP setup message frame and the address of the Ethernet MAC included in the CPU, Or a preset value; And (d-2), if it is determined in step (d-1) that the first half of the address of the Ethernet MAC or a preset value matches the DHCP setting message response signal for the DHCP setting message broadcast, Making the VLAN group not operate as a DHCP server; . Preferably, the DHCP setup message response signal is a DHCP Offer and Ack signal.

Preferably, in the method for setting and operating a DHCP server of a subnet in a data transmission apparatus using a virtual LAN according to another aspect of the present invention, the step (a) described above includes: (a-1) Determining whether a signal received through the port is a broadcast signal or a unicast signal; (a-2) determining whether the broadcast signal is a DHCP setting message in the step (a-1); And (a-3) transmitting a unicast frame signal through an L2 Ethernet switch corresponding to a transmission to a destination address included in the unicast signal when the signal is unicasted in the step (a-1) .

Although not explicitly mentioned as a preferred form of the invention, it is to be understood that embodiments in accordance with the various possible combinations of the above-mentioned technical features are feasible.

According to an aspect of the present invention, in a data transmission apparatus having an L2 Ethernet switch connected through a single physical port to a CPU having one Ethernet MAC, a virtual LAN is formed to form a virtual LAN group between an internal network and an external network So that the data can be transmitted and separated.

In addition, when the system operates as a DHCP server and a DHCP client in a system having a single physical port (Ethernet MAC) on the CPU, the WAN side acts as a DHCP client to the external network and the LAN side acts as a DHCP server to the internal network .

It is apparent that various effects not directly referred to in accordance with various embodiments of the present invention can be derived by those of ordinary skill in the art from the various configurations according to the embodiments of the present invention.

1 is a schematic block diagram of a DHCP server setting and operating system for a subnet in a data transmission apparatus using a virtual LAN according to an embodiment of the present invention.
FIG. 2A is a diagram schematically showing operation control to a DHCP server in the embodiment according to FIG.
FIG. 2B is a diagram schematically illustrating a network environment in which operation control to the DHCP server according to FIG. 2A is performed.
2C shows an example of a message for DHCP setting.
FIG. 3 is a schematic block diagram showing one use installation example of the embodiment according to FIG.
4 is a flowchart schematically illustrating a method of operating a DHCP server setting and operating system in a subnet in a data transmission apparatus using a virtual LAN according to another embodiment of the present invention.
5 is a flowchart illustrating a method of operating a DHCP server setting and operating system in a subnet in a data transmission apparatus using a virtual LAN according to another embodiment of the present invention.
6 is a flowchart schematically illustrating a method of operating a DHCP server setting and operating system in a subnet in a data transmission apparatus using a virtual LAN according to another embodiment of the present invention.
7A and 7B are schematic block diagrams showing a subnet system in a conventional data transmission apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. In the description of the embodiments, the same reference numerals denote the same components, and additional descriptions that may overlap or limit the meaning of the invention may be omitted from the description of the embodiments of the present invention.

Prior to the specific description, unless stated to the contrary, in the present specification and specification that one element is referred to as being either "connected" or "connected," unless expressly stated to be "directly connected" May be "connected" or connected directly to the other component, and further, insofar as the description is contradictory or contrary to the concept of the invention, another component is connected or connected It should be understood that the present invention can also exist as

It will be understood by those skilled in the art that the present invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. And is used interchangeably to mean plural unless expressly contradicted by interpretation or expressly expressly mean otherwise. It is to be understood that the terms 'comprises', 'comprising', 'comprising', 'comprising' and the like do not preclude the presence or addition of one or more other features or components or combinations thereof .

Also, in the present invention and the specification, 'Ethernet address', 'Ethernet MAC address', 'MAC address', 'physical address', etc. all mean a physical access address of each device on the network as a media access control address on a computer networking Preferably, the same vocabulary is used for the same device in the network, but it should be understood that the vocabulary is the same for the same device in the network and different values for different devices in the network, regardless of whether the vocabulary is the same .

1 is a schematic block diagram of a DHCP server setting and operating system for a subnet in a data transmission apparatus using a virtual LAN according to an embodiment of the present invention.

Referring to FIG. 1, a DHCP server configuration and operation system for a subnet in a data transmission apparatus using a virtual LAN according to an embodiment of the present invention includes a CPU 10 and an L2 Ethernet switch 20, .

The CPU 10 has one Ethernet MAC (Media Access Controller) 11. The Ethernet MAC operates at the data link layer specified in the seven layer OSI model and determines the physical address of the Ethernet.

The L2 Ethernet switch 20 includes a physical CPU port 21 connected to the Ethernet MAC 11, an external network port 23 connected to the external network, and an internal network port 24). Preferably, the L2 Ethernet switch 20 is controlled by the CPU 10 via MDC / MDIO (Management Data Clok / Management Data I / O). The Ethernet MAC 11 of the CPU 10 and the physical CPU port 21 of the L2 Ethernet switch 20 are connected through a media independent interface (MII). The external network port 23 has a WAN port for connecting to an external network or the external Internet. The external network port 23 is connected to the external network or the external Internet using RJ-45 or the like. The internal network port 24 is connected to internal devices (not shown), which may be connected using, for example, an RJ-45 with an embedded Ethernet transformer, and preferably a power line communication (PLC) physical layer MII interface. MII is a standard for the way in which devices that are responsible for physical connection, such as PLC communication or Ethernet communication, and the media access controller (MAC) part are interconnected.

A first VLAN group including the CPU 10 and the physical CPU port 21 of the L2 Ethernet switch 20 and the external network port 23 is formed and the CPU 10 and L2 Ethernet switch The second VLAN group including the physical CPU port 21 and the internal network port 24 of the second network 20 is formed. For example, the first VLAN group becomes the WAN side and the second VLAN group becomes the LAN side. The internal network port 24, which is part of the second VLAN group, is composed of a plurality of ports. Referring to FIG. 1, port 4 (P4) is connected to a power line communication with a media independent interface, and has a MAC to be connected to a physical layer (PLC PHY) of power line communication. For example, in the case of a data transmission device used for meter reading of a meter or the like, an internal network port 24 like the port 4 (P4) of FIG. 1 is required because it is often connected to the internal network through a PLC . Port 3 (P3) is connected using RJ-45. 1 shows only one port connected using RJ-45, but it may be composed of a plurality of ports. Although not mentioned, it is possible to provide an interface port suitable for transmission specifications in Ethernet other than RJ-45. 1, the PHY CPU port 21, P0, P1 and P2 of the L2 Ethernet switch 20 constitute the first VLAN group, and the PHY CPU port 21, P3 and P4 of the L2 Ethernet switch 20 constitute the first VLAN group. 2 VLAN groups are formed. 1, one or more external network ports 23 belonging to the second VLAN group are also provided. For example, in the case of a data transmission device used for meter reading of a meter, an external network port 23 is usually formed by only one WAN port, but a plurality of external network ports may be provided, and the remaining ports may be used as a switching hub.

In the present embodiment, the CPU 10 of the first VLAN group operates as a DHCP client for the external network and the CPU 10 of the second VLAN group operates as a DHCP server for the internal network. In other words, in the present embodiment, the CPU 10 operates as a DHCP client for the external network in the first VLAN group, and operates as a DHCP server for the internal network in the second VLAN group.

Accordingly, unlike the conventional method in which two switch devices are used when a plurality of network ports separated from the LAN / WAN in the data transmission apparatus are used, it is connected to one Ethernet MAC 11 of the CPU 10 using the VLAN method Multiple LAN / WAN network ports can be used with only one L2 Ethernet switch device. The CPU 10 is provided with one Ethernet MAC 11 so that it can operate as a CPU having two Ethernet MACs, and the number of Ethernet switch controllers can be reduced from two to one.

According to an embodiment of the present invention, communication between the VLAN groups can not be established unless the CPU 10 establishes connection between the VLAN groups, and packet broadcast such as ARP is transmitted. On the other hand, the broadcast storm is prevented by the VLAN set L2 switch function. CPU 10 belongs to both the first and second VLAN groups and can access both of them.

An example of the network IP setting (IP-aliasing) of the CPU 10 will be described. IP-aliasing refers to assigning two or more addresses to an interface. For example, you can assign two IP addresses to the eth0 ethernet card to allow access to either address. If two addresses belong to the same network, it is called network aliasing. The following eth0 and eth0: 1 are, for example, two physical LAN cards of the data transfer apparatus using the virtual LAN according to the present invention, and two virtual LAN cards forming two VLANs.

eth0: 192.168.10.40/24, gateway: 192.168.10.1

eth0: 1: 192.168.1.1/24

The first eth0 is for the first VLAN group, and IP address and gateway address are set. The second eth0: 1 is for the second VLAN group where the network IP setting is made, and the IP address is assigned but the gateway address is not set. Two IP addresses are assigned, but one is physically a CPU card. The first eth0 indicates that the eth0 LAN card of the data transmission apparatus using the virtual LAN according to the present invention belongs to the upper network and the gateway address constituting the upper network is 192.168.10.1, whereas the second eth0: 1 is given a separate gateway address Do not.

Next, an example of the networking setting of the internal network device belonging to the second VLAN group will be described. The following eth1 is the LAN card of the internal network device belonging to the second VLAN group.

eth1: 192.168.1.33/24, gateway: 192.168.1.1

In case of an internal network device belonging to the second VLAN group, a gateway is set. The internal network devices belonging to the second VLAN group must be set up with a gateway to enable Internet or other TCP / IP communication. Since the CPU 10 in the second VLAN group operates as a DHCP server with respect to the internal network, the IP address of the second VLAN group virtual LAN card set by the CPU 10, i.e., 192.168.1.1 of the preceding eth0: It becomes the gateway address of network devices.

Further, according to the embodiment of the present invention, in a case where a system having a single physical port (Ethernet MAC) in the CPU needs to operate as a DHCP server and a DHCP client, a DHCP server setting module of the CPU 10, The program needs to determine whether the DHCP setup message is a DHCP client request sent from the WAN side of the first VLAN group or a DHCP client sent from the LAN side of the second VLAN group.

In this case, according to one embodiment of the present invention, a DHCP setting message broadcast from a device belonging to an external network or an internal network, for example, a DHCP Discover or Request message, is transmitted to the port 23 of the L2 Ethernet switch 20, 24, the CPU 10 controls the second VLAN group to operate as a DHCP server when the port on which the DHCP setting message frame is received is the internal network port 24. If the port on which the DHCP setting message frame is received is the external network port 23, the CPU 10 ignores the DHCP setting message and controls the first VLAN group not to operate as a DHCP server. That is, the second VLAN group operates as a DHCP server on the basis of the receiving port of the DHCP setting message, and controls the first VLAN group not to operate as a DHCP server.

Here, DHCP is a protocol applied to the application layer, which is the OSI 7 layer. The DHCP setup message to be broadcast is created in the application layer of the DHCP client, reaches the application layer of the DHCP server, . In the meantime, in the case of an ARP packet to be broadcasted, since ARP is a protocol operating in the network layer, it is processed in a lower layer of the application layer, for example, a network layer (or IP layer) It need not be processed by the program (DHCP server setting program). Since the system of the present invention is implemented in a data transmission device such as a switch, a unicast signal received through an external network is transmitted to a corresponding destination address.

According to the present embodiment, the DHCP setting request sent from the DHCP client requesting the DHCP setting on the first VLAN group side (WAN side), for example, from the system A3 in Fig. 2B is ignored and accordingly, in the environment shown in Fig. The system of the present invention, such as the system An or the system A2 in FIG. 2B, sends a wrong response to the DHCP setting request of the system A3, so that the WAN side (first VLAN group side) (The second VLAN group side) of the system A of the system A 1 or the system A 2 of the system A 2.

The embodiment of the present invention will be described in more detail with reference to FIGS. 2A to 2C. FIG. 2A is a diagram schematically showing operation control to a DHCP server in the embodiment according to FIG. 1, FIG. 2B is a view schematically showing a network environment in which operation control to a DHCP server according to FIG. And shows an example of a message for DHCP setting.

2A, the DHCP server setting and operating system according to the present invention may include a data transmission device, and a DHCP server setting And a DHCP setting message broadcast from a subnet system including an operating system, a DHCP server setting of the other data transfer device, a terminal device belonging to the operating system, or a DHCP server setting and operating system of another data transmitting device and a belonging terminal device, For example, when a DHCP Discover or Request message is received, the CPU 10 analyzes the source Ethernet address included in the received DHCP setup message frame and transmits a DHCP setup message response signal, For example, the DHCP Offer and the Ack signal.

Here, the upper network is a system that is routed including the DHCP server setting and operating system of the subnet in the data transfer apparatus of the present invention and other systems. The other system may be the same system as the present invention or one terminal device or a subnet system including them. At this time, if a DHCP setting message, such as a DHCP Discover or Request message, is broadcast from another system, it is broadcast to the entire routing system, which is an upper network. The system of the present invention operates as a DHCP server for the second VLAN group and as a DHCP client for the first VLAN group. In the upper network, each system distinguishes the DHCP server of the other system from the DHCP server I can not. Therefore, as in the embodiment of the present invention, it is necessary to prevent the DHCP discover or request message broadcast from other systems in the upper network network from acting as a DHCP server.

2A, in accordance with another preferred embodiment of the present invention, the CPU 10 analyzes the first half of the Ethernet address of another system, in other words, the source Ethernet address, It is controlled so as not to return the DHCP setting message response signal, preferably the DHCP Offer and the Ack signal, when it matches the first half or the preset value of the address of the MAC 11.

The MAC address is a physical address of the Ethernet, and is generally 48 bits long. The first half is allocated to the manufacturer and is a unique number assigned by the manufacturer, and the second half is allocated for each device. Therefore, it is possible to analyze the first half of the source Ethernet MAC address to determine whether it matches the first half of the Ethernet MAC address of the system of the present invention, or whether it matches a pre-set value, It is possible to prevent the DHCP Offer and the Ack signal from being returned and to not operate as the DHCP server.

A detailed description will be given with reference to FIG. The subnet routing system in one embodiment operates as a DHCP server and a DHCP client, and therefore is referred to as a DHCP server system in FIG. In FIG. 2A, when the DHCP client system A3 broadcasts the DHCP discover, it is broadcast to both the DHCP server systems A2 and An and the ISP DHCP server. With respect to the DHCP discover broadcast of the DHCP client system A3, the DHCP server systems A2 and An, which are the subnet routing systems according to the embodiment of the present invention, analyze the Ethernet address of the DHCP client system A3, The DHCP offer is not transmitted. On the other hand, the ISP DHCP server returns a DHCP offer for the DHCP discover broadcast of the DHCP client system A3, and the DHCP client system A3 that has received the DHCP offer broadcasts a DHCP request broadcast. As in the case of the DHCP discover broadcast, the DHCP client broadcasts the DHCP request broadcast of the DHCP client system A3 by analyzing the Ethernet address of the DHCP client system A3 and does not return the DHCP ack. Only the ISP DHCP server issues a DHCP ack reply to the DHCP request broadcast of the DHCP client system A3, and the DHCP client system A3 receives the dynamic IP from the ISP DHCP server to perform communication.

3, another embodiment of the present invention will be described.

FIG. 3 is a schematic block diagram showing one use installation example of the embodiment according to FIG.

Referring to FIG. 3, a DHCP server setting and operating system of a subnet in a data transmission apparatus according to an embodiment of the present invention further includes a wireless communication module (see B-CDMA in FIG. 3). The wireless communication module is preferably a short-range wireless communication module, for example, a binary-CDMA (B-CDMA), a Zigbee, a Wi-Fi or a Bluetooth communication module. The wireless communication module is connected to the CPU 10 and wirelessly connected to an internal network or an external network device. At this time, the wireless communication module forms part of the first VLAN group when connected to the external network device, and forms part of the second VLAN group when connected to the internal network device.

When the DHCP setting message broadcasted from the external network or the internal network device is received through the wireless communication module, the CPU 10 determines whether the wireless communication module is wirelessly connected to the external network device or the internal network device .

More preferably, according to another aspect of the present invention, the CPU 10 analyzes a source address included in the received DHCP setting message frame, for example, a source Ethernet address, so that the wireless communication module can communicate with the external network device and the internal network device Which has been received wirelessly. For example, the source address included in the received DHCP frame, preferably the source Ethernet address, is analyzed to determine whether it matches the address of the routing device of the predetermined upper network or the address of the LAN card of the system, It is possible to know whether or not the radio signal is transmitted. Preferably, if the address matches the address of the predetermined upper network network routing device or the address of the LAN card of the system, it can be determined that the wireless signal is received by the external network.

The CPU 10 controls the second VLAN group including the wireless communication module to operate as a DHCP server when it is determined that the second VLAN group is connected to the internal network device. If it is determined that the first VLAN group is connected to the external network device, the first VLAN group including the wireless communication module is controlled not to operate as a DHCP server.

More specifically, referring to FIG. 3, the CPU 10 is connected to a remote meter reading load monitoring device interface, a memory, and a wireless communication module, preferably a short-range wireless communication module. In FIG. 3, the TDU I / F is a low voltage remote meter reading load monitoring device interface, and obtains measurement data such as current / voltage / phase of the power source and the power line from the TDU I / F. SDRAM and flash memory are shown as memories. A wireless communication module, for example, B-CDMA shown in FIG. 3, can communicate with an internal network device such as a power meter or the like through a WAN port which can not be connected to the external network through the external network port 23 10) The board can be connected to the external network wirelessly. For example, a wireless communication module of an upper network network routing apparatus connected to the Internet via a WAN port, so as to be connected to the external Internet. B-CDMA # 0 shown in FIG. 3 represents a case where B-CDMA, which is a wireless communication module (wireless LAN card) of a data transmission apparatus of the present invention, is wirelessly connected to an external network. B-CDMA # 1 is a wireless communication module (wireless LAN card) of a data transmission apparatus of the present invention, in which B-CDMA is wirelessly connected to an internal network device such as a meter to form an internal network. In this case, when using the TCP / IP stack (Stack), it can be named as the network device eth1 in case of B-CDMA # 0 and eth2 in the case of B-CDMA # 1. However, if you are not using the TCP / IP stack, do not name it as a network device.

In addition, the CPU 10 is connected to a host USB interface, and can update a program in a flash memory, for example, a DHCP server setting program, by connecting a USB memory in which a version upgrade program is stored, and can connect a wireless LAN module or a Bluetooth RF module And can perform wireless communication like B-CDMA.

The L2 Ethernet switch 20 is connected through a transformer to the WAN and the LAN, and is connected to the power line communication physical layer (PLC PHY) via the MII interface.

The routing function in the embodiment of the present invention will be described.

In the present invention, basically, communication is not possible between the VLAN groups unless the CPU 10 establishes connection between the two, so that the CPU 10 needs to establish a connection between the VLAN groups.

Accordingly, in one embodiment of the present invention, the CPU 10 uses the physical address of the network devices of the internal network obtained in the ARP (Address Resolution Protocol) communication and the routing table to transfer data between the first VLAN group and the second VLAN group So that transmission can be performed.

Also, preferably, according to another embodiment of the present invention, the L2 Ethernet switch 20 uses the physical address of the internal network devices analyzed from the frame signal of ARP (Address Resolution Protocol) communication through each port L2 switch function. Because ARP packets are forwarded to all ports, internal network devices connected to each port can create their own ARP tables. Internal network devices can communicate with other network devices in the internal network using their ARP tables. The L2 Ethernet switch 20 can function as an L2 switch because it can analyze the frame packets flowing between the ports and know the physical address of the device connected to each port.

Next, a DHCP setting and operation method of a subnet in a data transmission apparatus using a virtual LAN according to another aspect of the present invention will be described. Since the method of the present invention relates to a DHCP setting and operation method of a DHCP setting and operating system of a subnet in the data transmission apparatus using the virtual LAN, a specific content not directly explained below is transmitted to a data transmission apparatus Will be described with reference to embodiments of the DHCP setting and management system of the subnet in FIG.

FIG. 4 is a flowchart schematically illustrating a method of operating a DHCP server setting and operating system in a subnet in a data transmission apparatus using a virtual LAN according to another embodiment of the present invention. FIG. 5 is a flowchart 6 is a flowchart illustrating a method of configuring a DHCP server of a subnet in a data transmission apparatus using a virtual LAN according to an exemplary embodiment of the present invention and a method of operating the operating system. FIG. 2 is a flowchart schematically showing a configuration of a DHCP server of a subnet in a device and a method of operating the operating system. FIG.

4 to 6, the physical CPU port 21 and the external network port 23 on the L2 Ethernet switch 20 connected to the CPU 10 and the Ethernet MAC 11 with one Ethernet MAC 11, And a second VLAN group including the CPU 10 and the physical CPU port 21 and the internal network port 24 of the L2 Ethernet switch 20, An embodiment of the DHCP server setting and operation method of the subnet includes the following steps (a) to (d).

4, in step (a), the CPU 10 determines whether a signal received through the port of the L2 Ethernet switch 20 is a DHCP setting message broadcasted from an external network or an apparatus belonging to the internal network, , DHCP Discover or Request message.

Preferably, referring to Fig. 6, according to another embodiment of the present invention, step (a) includes the following steps (a-1) to (a-3).

In step (a-1), it is determined whether the signal received through the port of the L2 Ethernet switch 20 is a broadcast signal or a unicast signal from an apparatus belonging to the external network or the internal network. For example, it can be determined whether the broadcast signal is a destination address, preferably a destination physical address (FF: FF: FF: FF: FF: FF).

In step (a-2), the CPU 10 determines whether the broadcast signal is a DHCP setting message, preferably a DHCP Discover or Request message, in the case of the signal broadcasted in the step (a-1). The determination as to whether or not the DHCP setup message is made is made based on whether the port number of the IP packet included in the frame contents is a specific number, for example, '67'.

In step (a-3), when the signal is a unicast signal in step (a-1), the unicast signal is transmitted through the L2 Ethernet switch 20 corresponding to the transmission to the destination address included in the unicast signal. . The frame signal is changed to the corresponding port of the L2 Ethernet switch 20 by using the destination address and the routing table. If the data transmission apparatus includes a wireless communication module (refer to FIG. 3), if there is no corresponding port of the L2 Ethernet switch 20, the data is transmitted through the wireless communication module.

Referring again to FIG. 4, in the step (b), when it is determined in the step (a), preferably the DHCP setting message in the step (a-2), the CPU 10 determines that the external network port 23 and the internal network port (24).

Preferably, when the data transmission apparatus includes a wireless communication module (see FIG. 3), if the DHCP setting message is received through the wireless communication module, the CPU 10 determines whether the wireless communication module is an external network It is judged whether the device or the internal network device is wirelessly connected.

Next, in step (c), if it is determined that the packet is received through the internal network port in the previous step (b), the CPU 10 causes the second VLAN group to act as a DHCP server.

In step (d), if it is determined in step (b) that the packet is received through the external network port, the CPU 10 ignores the DHCP setting message and does not operate as a DHCP server for the first VLAN group.

FIG. 5 illustrates a step of disabling a DHCP server for the first VLAN group by ignoring the DHCP setup message shown in FIG.

5, in the step (d), the source Ethernet address included in the DHCP setup message frame received through the external network port is analyzed to prevent the DHCP server from acting as a DHCP server for the first VLAN group do.

More specifically, according to another embodiment of the present invention, step (d) includes steps (d-1) and (d-2).

In step (d-1), the CPU 10 analyzes whether the first half of the source Ethernet address included in the DHCP setup message frame matches the pre-set value of the address of the Ethernet MAC 11 provided in the CPU 10 or a preset value.

In step (d-2), if the result of the analysis in step (d-1) matches the pre-set address of the Ethernet MAC 11 or a preset value, the CPU 10 transmits a DHCP setting message It is controlled not to return the response signal, preferably the DHCP Offer and the Ack signal, so that the first VLAN group does not operate as a DHCP server.

In the foregoing, the present invention has been described with reference to the preferred embodiments thereof with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings and the foregoing embodiments are provided by way of illustration for purposes of clarity of understanding to those skilled in the art to which the present invention pertains. It is, therefore, to be understood that the various embodiments of the present invention may be embodied in various forms without departing from the essential characteristics thereof, and the above-described embodiments are to be considered as illustrative and not restrictive. Accordingly, the scope of the present invention should be construed in accordance with the invention as set forth in the appended claims rather than the foregoing embodiments, and various changes, alternatives, and equivalents by those skilled in the art may be made by the inventions It is obvious that it is included in the range of.

10: CPU 11: Ethernet MAC
20: L2 Ethernet switch 21: CPU port
23: external network port 24: internal network port

Claims (12)

A CPU having one Ethernet MAC; And
An L2 Ethernet switch having one physical CPU port connected to the Ethernet MAC, an external network port connected to the external network, and an internal network port connected to the internal network; , ≪ / RTI >
A first VLAN group including a physical CPU port and an external network port of the CPU and the L2 Ethernet switch and a second VLAN group including a physical CPU port and an internal network port of the CPU and the L2 Ethernet switch,
Wherein the CPU of the first VLAN group operates as a DHCP client with respect to the external network and the CPU of the second VLAN group operates with the DHCP server with respect to the internal network. DHCP server configuration and operating system on the subnet.
The method according to claim 1,
When a DHCP setting message broadcast from an appliance belonging to the external network or the internal network is received through the port of the L2 Ethernet switch,
Wherein the CPU operates as a DHCP server for the second VLAN group when the port on which the DHCP setup message frame is received is the internal network port and if the port on which the DHCP setup message frame is received is the external network port, Wherein the control unit controls the first VLAN group so as not to operate as a DHCP server by ignoring the setting message.
The method of claim 2,
A DHCP server setting and operating system of another data transmitting apparatus in an upper network including the data transmitting apparatus, a DHCP server setting of the other data transmitting apparatus, a terminal apparatus belonging to the operating system, or a DHCP server setting And when the DHCP setting message broadcasted from the subnet system including the operating system and the belonging terminal device is received,
Wherein the CPU analyzes the source Ethernet address included in the received DHCP setup message frame and controls not to return a DHCP setup message response signal so as not to operate as a DHCP server for the first VLAN group A DHCP server setup and operation system in the subnet of the data transfer device.
The method of claim 3,
Wherein the CPU analyzes the first half of the source Ethernet address and controls to not return a DHCP setting message response signal if the first half of the address of the Ethernet MAC or the preset value matches the predetermined value. A DHCP server setup and operation system in the subnet of the data transfer device.
5. The method according to any one of claims 1 to 4,
And a wireless communication module connected to the CPU and wirelessly connected to the internal network or the external network device,
Wherein the wireless communication module forms part of the first VLAN group when connected to the external network device and forms part of the second VLAN group when the wireless communication module is connected to the internal network device,
When a DHCP setting message broadcast in the external network or internal network device is received through the wireless communication module, the CPU determines whether the wireless communication module is wirelessly connected to the external network device or the internal network device However,
The CPU operates as a DHCP server with respect to the second VLAN group including the wireless communication module when it is determined to be connected to the internal network device, and when the CPU is determined to be connected to the external network device, Wherein the control unit controls the first VLAN group not to operate as a DHCP server.
The method of claim 5,
Wherein the CPU analyzes the source address included in the received DHCP setup message frame to determine whether the wireless communication module is wirelessly connected with the external network device or the internal network device. A DHCP server setup and operation system in the subnet of the data transfer device.
5. The method according to any one of claims 1 to 4,
When data is transmitted from the external network to the internal network,
Wherein the CPU transfers data between the first VLAN group and the second VLAN group using a physical address and a routing table of network devices of the internal network obtained through ARP (Address Resolution Protocol) communication, A DHCP server setup and operation system for a subnet in a data transmission device.
5. The method according to any one of claims 1 to 4,
Wherein the L2 Ethernet switch performs an L2 switch function using a physical address of internal network devices analyzed from a frame signal of ARP (Address Resolution Protocol) communication through each port. DHCP server configuration and operating system on the subnet.
A first VLAN group including a CPU having a single Ethernet MAC and a physical CPU port and an external network port on an L2 Ethernet switch connected to the Ethernet MAC and a physical CPU port and an internal network port of the CPU and the L2 Ethernet switch A method for setting and operating a DHCP server in a subnet in a data transmission apparatus forming a second VLAN group,
(a) determining whether a signal received through the port of the L2 Ethernet switch is a DHCP setting message broadcasted from an external network or an apparatus belonging to the internal network;
(b) determining which of the external network port and the internal network port is received when the DHCP setting message is determined in the step (a);
(c) if it is determined in the step (b) that the packet is received through the internal network port, the CPU operates as a DHCP server for the second VLAN group; And
(d) if it is determined in the step (b) that the packet is received through the external network port, the CPU ignores the DHCP setup message and does not operate as a DHCP server for the first VLAN group; And setting a DHCP server of the subnet in the data transmission apparatus using the virtual LAN.
The method of claim 9,
Wherein the step (d) analyzes the source Ethernet address included in the DHCP setup message frame received through the external network port, and does not operate as a DHCP server for the first VLAN group How to set up and operate a DHCP server on the subnet in the transmitting device.
11. The method of claim 10, wherein step (d) comprises:
(d-1) analyzing whether the first half of the source Ethernet address included in the DHCP setup message frame and the first half of the address of the Ethernet MAC or the preset value of the Ethernet MAC included in the CPU coincide with each other; And
(d-2) if the result of the analysis in the step (d-1) matches the pre-set address of the Ethernet MAC or a predetermined value, it is controlled not to return the DHCP setup message response signal for the broadcast, Making the group not operate as a DHCP server; And setting a DHCP server of the subnet in the data transmission apparatus using the virtual LAN.
The method according to any one of claims 9 to 11,
Wherein the step (a) comprises:
(a-1) determining whether a signal received through the port of the L2 Ethernet switch is a broadcast signal or a unicast signal from an apparatus belonging to the external network or the internal network;
(a-2) determining whether the broadcast signal is a DHCP setting message in the step (a-1); And
(a-3) transmitting a unicast frame signal through the L2 Ethernet switch corresponding to the transmission to the destination address included in the unicast signal when the signal is a unicast signal in the step (a-1) ; And setting a DHCP server of the subnet in the data transmission apparatus using the virtual LAN.

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