KR102163903B1 - Method and apparatus for udating network address information in a communication system using a wired/wireless bridge - Google Patents

Abstract

According to an embodiment of the present invention, a method of updating network address information in a communication system using a wired/wireless bridge includes a process in which the replaced bridge device acquires an IP address when the bridge device is replaced, and the replaced bridge device A process in which a device transmits a packet notifying the replacement of the bridge device to an internal network node, and a process in which the replaced bridge device broadcasts a message for updating the network address information to an external network node, and the message Table information including network address information is updated in the received external network node.

Description

Method and device for updating network address information in a communication system using wired/wireless bridges {METHOD AND APPARATUS FOR UDATING NETWORK ADDRESS INFORMATION IN A COMMUNICATION SYSTEM USING A WIRED/WIRELESS BRIDGE}

The present invention relates to a method and apparatus for managing network addresses in a communication system using a bridge device.

Communication systems using the bridge device include wired/wireless communication systems. The wired communication system using the bridge device may be, for example, an IEEE 802.3 based Ethernet system, and the wireless communication system may be a Wireless Local Area Network (WLAN) system. The wireless LAN system may be an IEEE 802.11 based wireless LAN system and a Wi-Fi/WLAN system based on the Wi-Fi Alliance.

The IEEE 802.11-based wireless LAN system is a local area network (LAN) capable of performing communication such as high-speed Internet within a certain distance of a place where a wireless access point (AP) is installed. Typically, communication is performed using a radio wave or infrared transmission method. Meanwhile, Wi-Fi is a term referring to IEEE 802.11 technology in the Wi-Fi Alliance, a non-profit organization centered on wireless LAN manufacturers and telecommunications operators. Therefore, both wireless LAN and Wi-Fi are used as terms referring to IEEE 802.11 based wireless technology. In the following description, "Wi-Fi/WLAN", "Wi-Fi", "WLAN", and "Wireless LAN" mean an IEEE 802.11-based wireless technology and may be used interchangeably.

Meanwhile, as Wi-Fi technology is installed in smart phones and smart home appliances, the number of devices for using Wi-Fi is rapidly increasing. These Wi-Fi/WLAN devices can form a multi-hop/mesh network by themselves, and the multi-hop/mesh network can be connected to an external communication network through a wireless access point (AP). . For reference, a mesh network is a network in which each node on the network exists as an independent router, and since each node is connected like a net, communication can be performed through another connection even if one connection is disconnected.

In order to connect Wi-Fi/WLAN devices to the external network, a bridge device is required. The bridge device is generally connected to the AP through a wired communication interface using an Ethernet cable. Bridge refers to a function of connecting different communication networks into a single network, and is generally implemented on Layer 2 (MAC layer) to connect different networks.

FIG. 1 is a diagram for explaining a bridge function for connecting different networks through a bridge device 10 in a general communication system.

Referring to FIG. 1, the bridge device 10 includes a plurality of physical layer (or PHY layer) interfaces 111 and 113 and a MAC layer interface 115 as network interfaces. The external network 101 and the internal network 103 may be connected 11 to each other through the bridge device 10 of FIG. 1. Each of the physical layer interfaces 111 and 113 is connected to different networks 101 and 103. A packet received from one network is transmitted to the bridge device 10 through the corresponding network interface 101 or 103, and the bridge device 10 finds the network to which this packet is destined and sends a packet to the network interface connected to the network. Deliver. Meanwhile, among the network interfaces constituting the bridge device, "wired bridge" and "wireless bridge" based on whether the communication interface in the direction to connect to the external network 101 is wired (Ethernet) or wireless (Wi-Fi/WLAN). It can be classified as ".

2 is a diagram illustrating a wired bridge device 20 in a general communication system. Referring to FIG. 2, the wired bridge device 20 includes a plurality of physical layer (or PHY layer) interfaces 211 and 213 and a MAC layer interface 215 as network interfaces, and a wired communication interface It is connected 21 to the external network 201 and the internal network 203, respectively, through the Ethernet interfaces 211 and 213.

In a typical communication system, a communication interface includes a physical layer, a MAC layer (including a bridge), and a TCP/IP (Transfer Control Protocol/Internet Protocol) layer. Packets generated by the sender are transferred to the MAC layer and TCP/IP layer through the physical layer. At this time, each layer transfers only the packets necessary for itself among the received packets to the next layer. Specifically, the physical layer receives all packets generated by the sender and delivers them to the MAC layer, and the MAC layer checks the MAC address of the packet, and the destination address of the packet is set as its own MAC address. Only packets are delivered to the upper layer, the TCP/IP layer.

In the wired bridge device 20 as shown in FIG. 2, a "promiscuous mode" is used when a packet is received. Promiscuous mode is a mode in which all packets received from the bridge are accepted. That is, when the promiscuous mode is used, the MAC layer of the bridge transfers all packets including packets having a MAC address other than the MAC address of the bridge as well as packets having a MAC address of the bridge to the bridge. The bridge device 20 sees the MAC address of the packet, transfers the packet having the MAC address of the bridge device 20 to the TCP/IP layer, and transfers the packet having a different MAC address to the network corresponding to the MAC address. Deliver.

3 is a diagram illustrating a wireless bridge device 30 in a general communication system. Referring to FIG. 3, the wireless bridge device 30 includes a plurality of physical layer (or PHY layer) interfaces 311 and 313 and a MAC layer interface 315 as network interfaces, and a wireless communication interface The external network 301 and the internal network 303 are connected 21 to each other through a Wi-Fi/WLAN interface (hereinafter, a Wi-Fi interface) 311 and an Ethernet interface 313 that is a wired communication interface. Meanwhile, the Wi-Fi interface does not support the above-described brute force mode. There is a difference between the MAC layer used in the wired communication interface and the wireless communication interface in a carrier sensing method. Because of this difference, the brute force mode cannot be used in the wireless bridge.

In this regard, when a wired bridge device is used and then replaced with a wireless bridge device, or vice versa, it is necessary to update the ARP table. Here, ARP (Address Resolution Protocol) is a protocol used to change an IP address to a unique MAC address of a network device, and is used to find a MAC address when the IP address of a network device is known. In addition, an address table mapped between an IP address and a MAC address based on ARP is called an ARP table.

When a wired bridge device is used for the same network device and when a wireless bridge device is used, the registered MAC address is different, and when an external network device (or node) sees a network device (or node) in the internal network connected to the bridge device. The MAC address is different. In the case of a wired bridge device, the actual MAC address of the network device is used, but in the case of a wireless bridge device, the MAC address of the corresponding bridge device is used as the MAC address of the network device.

Therefore, it is necessary to update the ARP table in the case of using a wired bridge device and then changing to a wireless bridge device or vice versa.

Accordingly, the present invention provides a method and apparatus for efficiently updating a network address when a bridge device is replaced (changed) in a communication system using a bridge device.

In addition, the present invention provides a method and apparatus for updating an ARP table when switching between wired/wireless bridge devices in a communication system using a bridge device.

In addition, the present invention provides a method and apparatus for efficiently performing replacement between wired/wireless bridge devices in a network layer 2 of a communication system using a bridge device.

A method of transmitting and receiving packets in a bridge device of a communication system according to an embodiment of the present invention is to transmit a first packet having the MAC layer source address from a wireless device having a medium access control (MAC) layer source address in a first network. A process of generating a first address replacement packet by replacing the MAC layer source address of the received first packet with a MAC address of the bridge device; and a process of generating a first address replacement packet to a node of a second network. The transmission process, the process of receiving a second packet from the second network, and the MAC destination address of the received second packet based on the Internet Protocol (IP) and MAC address table for the first network The second address replacement packet may be generated by replacing the second packet with the MAC address of the actual destination node, and the second address replacement packet may be transmitted to the first network.

In addition, a bridge device for transmitting and receiving packets in a communication system according to an embodiment of the present invention includes a first packet having the MAC layer source address from a wireless device having a medium access control (MAC) layer source address in a first network. And a transceiver configured to receive a second packet from a second network and a first address replacement packet by replacing the MAC layer source address of the received first packet with a MAC address of the bridge device, The address replacement packet is transmitted to the node of the second network, and the MAC destination address of the received second packet is determined based on the Internet Protocol (IP) and MAC address table for the first network. It may include an address management unit configured to generate a second address replacement packet by replacing it with the MAC address of the destination node, and to transmit the second address replacement packet to the first network.
In addition, a communication method of a bridge device including a bridge in a communication network according to an embodiment of the present invention includes a process of identifying that the bridge is replaced, and an Internet Protocol (IP) address of a first network node located inside the communication network. A process of acquiring and transmitting a packet indicating that the bridge is replaced using the IP address to the first network node, and information of the replaced bridge with a second network node located outside the communication network. It may include a process of broadcasting a message for updating.
In addition, the method of updating network address information in a communication system using a bridge device according to an embodiment of the present invention is a process of obtaining an Internet Protocol (IP) address by the replaced bridge device when the bridge device is replaced. And, transmitting a packet indicating replacement of the bridge device to an internal network node by the replaced bridge device, and broadcasting a message for updating the network address information to an external network node by the replaced bridge device. And wherein the table information including the network address information is updated in the external network node that has received the message.
In addition, a bridge device in a communication system according to an embodiment of the present invention includes a first network interface configured to communicate with an external network, a second network interface configured to communicate with an internal network, and when the bridge is replaced, the Internet Protocol (IP ) Control a bridge function to acquire an address, transmit a packet indicating replacement of the bridge to a node of the internal network through the second network interface, and a network address to a node of the external network through the first network interface A MAC (medium access control) layer interface for broadcasting a message for updating information, wherein table information including the network address information is updated in the external network node that has received the message.

1 is a diagram for explaining a bridge function for connecting different networks through a bridge device in a general communication system;
2 is a diagram for explaining a wired bridge device in a general communication system;
3 is a diagram for explaining a wireless bridge device in a general communication system;
4 is a diagram showing an example configuration of a communication system including a bridge device according to an embodiment of the present invention;
5 is a diagram for explaining the operation of a communication system including a bridge device according to an embodiment of the present invention;
6 is a diagram illustrating an ARP table update method when a bridge device is changed from a wired bridge device to a wireless bridge device according to an embodiment of the present invention;
7 is a diagram illustrating a method of updating an ARP table when a bridge device 40 is changed from a wireless bridge device to a wired bridge device according to an embodiment of the present invention.

In the following description of embodiments of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

4 is a diagram illustrating an example configuration of a communication system including a bridge device according to an embodiment of the present invention.

Referring to FIG. 4, the bridge device 40 includes a plurality of physical layer interfaces 411 and 413 and one MAC layer interface 415. The MAC layer interface 415 performs a bridge function. Among the plurality of physical layer interfaces 411 and 413, the first network interface 411 is a communication interface for connection with the external network 401, and the second network interface 413 is communication for connection with the internal network 403 Interface.

When the bridge device 40 of FIG. 4 is a wired bridge device, the first network interface 411 uses a wired interface such as an Ethernet interface, and in the case of a wireless bridge device, the first network interface 411 is Wi Use a wireless interface such as -Fi interface. In addition, the second network interface 413 may selectively use a wired interface and a wireless interface regardless of whether the bridge device 40 is a wired or wireless bridge device.

However, the packet transmitted to the internal network 403 through the second network interface 413 includes an Ethernet header. Therefore, if the second network interface 413 is a wired interface, an Ethernet interface can be used, and if the second network interface 413 is a wireless interface, a packet transmitted to the internal network 403 is printed to include an Ethernet header through the second network interface 413. It is encapsulated.

In addition, in FIG. 4, the external network 401 and the internal network 403 may each include a plurality of nodes, and for convenience of description, the internal network 401 includes first and second nodes 401-1 and 401. -2), and the external network 403 is assumed to include the third and fourth nodes 403-1 and 403-2.

In a communication system using a wired/wireless bridge as in the embodiment of FIG. 4, the bridge device 40 includes a first network interface 411 for communication with an external network and a second network interface 413 for communication with an internal network. ), when changing between the wired/wireless bridge, obtains an IP address, transmits a packet notifying the bridge change to a node of the internal network 403 through the second network interface 413, and the first network It includes a MAC layer interface 415 for controlling a bridge function for broadcasting a message for updating network address information including the ARP table to a node of the external network 401 through the interface 411, and receiving the message In the node of the external network 401, table information including the network address information is updated.

FIG. 5 is a diagram for explaining the operation of a communication system including a bridge device according to an embodiment of the present invention. In FIG. 5, the same reference numerals are assigned to the same components as those of FIG. 4.

Referring to FIG. 5, when the bridge device 40 is changed from a wired bridge device to a wireless bridge device or from a wireless bridge device to a wired bridge device due to network interface replacement, the bridge device 40 and the external network 401 ) And the operation of the external network 403 are as follows.

The bridge device 40 acquires each IP address of nodes in the internal network. That is, the IP address means the IP addresses of nodes of the internal network connected to the bridge device 40. In addition, the MAC address mapped to the IP addresses in the ARP table means the MAC address of the corresponding bridge device 40.

The bridge device 40, which has obtained the IP address, transmits a multicast packet to the internal network 403 to notify that the corresponding bridge device 40 has been changed (501). Then, the bridge device 40 of the external network 401 To update the ARP table, a message (eg, a gARP message) is broadcast to the external network 401 within a predetermined number of times. The gARP message may use a gARP request message or a gARP response message. (503) The gARP message may use a request/response message specified in ARP, a protocol used to change an IP address to a unique MAC address of a network device. have.

In addition, when the third and fourth nodes 403-1 and 403-2 of the internal network 403 receive the multicast packet from the bridge device 40 as described above, they recognize that the bridge device 40 has changed. And, in order to update the ARP table of the external network 401, a gARP message is broadcast to the internal network 403 within a predetermined number of times. Here, the gARP message may also use a gARP request message or a gARP response message as described above. (505, 507)

And, the first and second nodes 401-1 and 401-3 of the external network 401, which have received the gARP message broadcast from the internal network 403, are in their own ARP table and FDB (Forwarding DataBase) table. The included MAC address is updated to a new MAC address. Here, the FDB table refers to a table for mapping the MAC address of a target node and a communication port.

6 is a diagram showing a method of updating an ARP table when a bridge device 40 is changed from a wired bridge device to a wireless bridge device according to an embodiment of the present invention, reference numeral 50 is a node of the internal network 403, reference numeral 60 Represents a node of the external network 401 for convenience.

Referring to FIG. 6, in step 601, the bridge device 40 is changed to a wireless bridge device by changing a network interface or the like. In step 603, the bridge device 40 obtains an IP address, and in step 605, the bridge device 40 transmits a multicast packet informing that the corresponding bridge device 40 has been changed to the internal network node 50. In addition, in step 607, the bridge device 40 broadcasts a gARP message within a predetermined number of times to the external network node 60 to update the ARP table of the external network. In step 609, the external network node 60, each receiving the gARP message broadcast by the bridge device 40, updates the MAC address included in its ARP table and the FDB table to a new MAC address.

On the other hand, when receiving the multicast packet, the internal network node 50 recognizes that the corresponding bridge device 40 has been changed, and in step 611, the external network node 60 to update the ARP table of the external network node 60 The gARP message is broadcast within the number of times specified by.

And, upon receiving the gARP message broadcast by the internal network node 50, the bridge device 40 generates and updates a mapping table between the IP address and the MAC address in step 613. In step 615, the external network node 60 receiving the gARP message broadcasted by the internal network node 50 updates the MAC address included in its ARP table and FDB table to a new MAC address.

7 is a diagram illustrating a method of updating an ARP table when a bridge device 40 is changed from a wireless bridge device to a wired bridge device according to an embodiment of the present invention.

Referring to FIG. 7, in step 701, the bridge device 40 is changed to a wired bridge device by changing a network interface or the like. In step 703, the bridge device 40 acquires an IP address, and in step 705, the bridge device 40 transmits a multicast packet informing that the corresponding bridge device 40 has been changed to the internal network node 50. In addition, in step 707, the bridge device 40 broadcasts a gARP message within a predetermined number of times to the external network node 60 to update the ARP table of the external network.

Thereafter, in step 709, the bridge device 40 flushes and deletes the mapping table between the IP address and the MAC address managed by itself.

Meanwhile, when receiving the multicast packet, the internal network node 50 recognizes that the corresponding bridge device 40 has been changed, and in step 713, the external network node 60 to update the ARP table of the external network node 60 The gARP message is broadcast within the number of times specified by. In addition, the external network node 60, which has received the gARP message broadcast by the internal network node 50, updates the MAC address included in its ARP table and FDB table to a new MAC address.

According to the embodiment of the present invention, when a wired/wireless bridge is replaced in network layer 2, for example, when a wireless bridge device using a Wi-Fi/WLAN interface is replaced with a wired bridge device using an Ethernet interface. In addition, other nodes in the network can quickly update the ARP table to reduce the delay time required for data exchange after bridge replacement.

Claims (20)

delete delete delete delete In a communication method of a bridge device including a bridge in a communication network,
The process of identifying that the bridge is to be replaced,
The process of obtaining an Internet Protocol (IP) address of a first network node located inside the communication network,
Transmitting a packet indicating that the bridge is replaced to the first network node using the IP address, and
And broadcasting a message for updating information of the replaced bridge to a second network node located outside the communication network.
The method of claim 5,
The message includes the IP address and the MAC (medium access control) address of the replaced bridge.
The method of claim 5,
The packet comprises a multicast packet.
The method of claim 5,
And the message is broadcasted at a predetermined number of times.
The method of claim 6,
After broadcasting a message for updating information of the replaced bridge, when the replaced bridge is a wireless bridge, updating a mapping table between the IP address of the first network node and the MAC address of the replaced bridge How to further include.
The method of claim 9,
After broadcasting a message for updating information of the replaced bridge, if the replaced bridge is a wired bridge, deleting the managed mapping table before replacing the bridge.
In a method for updating network address information in a communication network using a bridge device,
The process of identifying that the bridge device is to be replaced,
The process of obtaining an Internet Protocol (IP) address by the replaced bridge device,
Transmitting a packet indicating replacement of the bridge device to an internal network node by the replaced bridge device, and
And broadcasting a message for updating the network address information to an external network node by the replaced bridge device.
delete The method of claim 11,
The packet indicating the replacement of the bridge device comprises a multicast packet.
The method of claim 11,
After broadcasting the message for updating the network address information, the method further comprising the step of deleting or updating the mapping table between the IP address and the MAC (medium access control) address by the replaced bridge device.
The method of claim 11, wherein after broadcasting a message for updating the network address information,
When the replaced bridge device is a wireless bridge device, updating a mapping table between the IP address and a medium access control (MAC) address by the replaced bridge device,
If the replaced bridge device is a wired bridge device, the method further comprising the step of deleting the mapping table.
In the bridge device in a communication system,
A first network interface configured to communicate with an external network,
A second network interface configured to communicate with an internal network,
The bridge device,
Identify that the bridge is being replaced,
Control the bridge function to obtain an Internet Protocol (IP) address,
Transmitting a packet indicating replacement of the bridge to a node of the internal network through the second network interface,
A bridge device, configured to broadcast a message for updating network address information to a node of the external network through the first network interface.
delete The method of claim 16,
The packet indicating the replacement of the bridge includes a multicast packet.
The method of claim 16,
The bridge device is configured to delete or update a mapping table between the IP address and a medium access control (MAC) address.
The method of claim 16, wherein the bridge device,
If the replaced bridge is a wireless bridge, updating the mapping table between the IP address and MAC (medium access control) address,
Bridge device configured to delete the mapping table when the replaced bridge is a wired bridge.

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