JP4873556B2 - Topology detection method, communication device, management device, and program for detecting logical topology of network - Google Patents

Description

  The present invention relates to a topology detection method, a communication device, a management device, and a program for detecting a logical topology of a network.

  At present, Ethernet (registered trademark) technology is widely used as a layer 2 network for LAN (Local Area Network). On the other hand, in recent years, FTTH (Fiber To The Home) technology has been used as an ultra-high-speed layer 2 network. With the FTTH technology and other high-speed access line technologies, the communication network including the core network and the metro network needs to be increased in capacity as the communication speed of the access network increases. In addition to the improvement in the communication speed of the entire network, it is also necessary to increase the switching processing capacity of a communication apparatus such as a layer 2 network apparatus and increase the communication speed between layer 2 network apparatuses.

  Service providers need to perform operation administration and maintenance (OAM) from a remote location in order to provide a stable service to subscribers at all times. Therefore, ITU-T Y.T. An Ethernet OAM frame has been defined by 1731 or IEEE802.1ag (see, for example, Non-Patent Document 1). In particular, ITU-T Y.M. 1731 is a standard that realizes an operation and maintenance management function almost equivalent to SONET (Synchronous Optical NETwork) in the Ethernet network.

  The Ethernet OAM frame is a frame having functions such as reachability management (CFM: Connectivity Fault Management), error notification, link (line) performance monitor, and the like and a function for transmitting the information. The Ethernet OAM frame includes a destination MAC (Media Access Control) address, a source MAC address, an Ethernet OAM TLV (Type, Length, and Value), and an FCS (Frame Check Sequence). The MAC address is a 48-bit identification number that is unique to the layer 2 network device that is the target of operation and maintenance management or unique to the network interface card. Normally, the layer 2 network device does not use the unique identifier of the network interface card, but recognizes the device at the time of frame transfer using one device MAC address (CPU-MAC address) that identifies the device itself. To do. The Ethernet OAM TLV includes, for example, control information (request / response), status (power status, received light status, link disconnection, failure, etc.), vendor code, model code, and the like.

  FIG. 1 is a sequence diagram of path trace in the prior art.

  According to the route trace (Traceroute) function of FIG. 1, the management device transmits a trace request to a target network, that is, to an adjacent layer 2 network device. The trace request is, for example, ETH-LTM (ETHernet Link Trace Massage) in an Ethernet OAM frame that is an operation maintenance management frame. An unknown (unknown) is set as the destination address of the ETH-LTM, and a maximum value (for example, 64) is set as the TTL.

  The layer 2 network device that has received the ETH-LTM generates a trace response in which the source MAC address of the ETH-LTM is the destination MAC address. The trace response is, for example, an ETH-LTR (ETHernet Link Trace Reply) in an Ethernet OAM frame that is an operation maintenance management frame. The layer 2 network device returns the ETH-LTR to the port that received the ETH-LTM. As a result, the ETH-LTR is returned to the management apparatus that has transmitted the ETH-LTM.

  In addition, the layer 2 network device further decrements the TTL of the received layer 2 frame by 1 and further broadcasts an ETH-LTM having the destination address unknown from other ports. This is repeated until TTL becomes zero. The ETH-LTM broadcasted in the network and the layer 2 network device that has received the ETH-LTM returns the ETH-LTR to the management device. Thereby, the management apparatus can receive the ETH-LTR from all the layer 2 network apparatuses in the network. Therefore, the management device can know the device topology of the layer 2 network device in the network.

Koichiro Seto, “Standardization Trend of 802.1 / 802.3 (3)”, [online], September 25, 2006, WBB Forum, [October 31, 2006 search], Internet <URL: http: //wbb.forum.impressrd.jp/report/20060922/280?page=0%2C0>

  In general, according to a large-scale layer 2 network device and a layer 2 transmission device having a layer 2 processing function for each interface, the device MAC address (CPU-MAC address) and the port MAC address are different. The management apparatus can transmit and receive ETH-LTM / LTR. Therefore, in this case, the management apparatus can know not only the apparatus topology but also the port topology that is the connection port information of the apparatus by the MAC address. The management device can improve operation, maintenance, and management by knowing the port topology.

  However, in the case of a simple layer 2 network device for general consumers, it is managed only by the device MAC address. Therefore, in this case, the management device can only know the device topology based on the device MAC address.

  Therefore, the present invention provides a topology detection method, a communication device, a management device, and a program capable of detecting not only the device topology but also the port topology for a layer 2 network device managed only by the device MAC address. With the goal.

According to the present invention, there is provided a topology detection method in a system including a plurality of communication devices that relay layer 2 frames between a plurality of ports, and a management device that detects a logical topology of a network to which the communication devices are connected. ,
The communication device records transfer information in which a port number and a source MAC (Media Access Control) address are associated with each other,
A first step of transmitting a trace request including the TTL to the communication device every time the management device increments a TTL (Time To Live) by 1 in order,
A second step in which the communication device returns a trace response including transfer information to the management device in response to a trace request of TTL = 1;
The management device has a third step of obtaining transfer information from the received trace response and deriving a port topology in the device topology of the network.

  According to another embodiment of the topology detection method of the present invention, the trace request and the trace response are Ethernet OAM frames that are operation and maintenance management frames, the trace request is an ETH-LTM, and the trace response is an ETH- It is also preferable that it is LTR.

According to the present invention, in a communication apparatus having switch control means for relaying a layer 2 frame between a plurality of ports,
Transfer information recording means for recording transfer information in which a port number of a port through which a layer 2 frame is input and output is associated with a source MAC address;
Trace request determination means for determining whether or not TTL = 1 for the trace request received from the port;
In response to a trace request with TTL = 1, a trace response generation unit that generates a trace response with the source MAC address of the trace request as a destination MAC address and includes the transfer information recorded in the transfer information recording unit in the trace response And
The switch control means returns a trace response from the port that received the trace request.

  According to another embodiment of the communication apparatus of the present invention, the trace request and the trace response are Ethernet OAM frames that are operation and maintenance management frames, the trace request is an ETH-LTM, and the trace response is an ETH-LTR. It is also preferable.

According to the present invention, a management device that detects a logical topology in a network to which a plurality of communication devices described above are connected,
Port trace transmission / reception means for transmitting a trace request including the TTL to the communication device and receiving a trace response each time the TTL is incremented by 1 from 1
And port topology detection means for obtaining transfer information from the received trace response and deriving a port topology in the network device topology.

According to another embodiment of the management device of the present invention,
Device trace transmission / reception means for transmitting a trace request including a TTL that is the maximum value in the network to the communication device and receiving a trace response from all of the communication devices;
It is also preferable to further include device topology detecting means for deriving the device topology of the network from the trace response.

According to the present invention, there is provided a program for causing a computer mounted on a communication device having a plurality of ports to function, wherein the communication device causes the computer to function as switch control means for relaying a layer 2 frame between ports.
Transfer information recording means for recording transfer information in which a port number and a source MAC address are associated with each other;
Trace request determination means for determining whether or not TTL = 1 for the trace request received from the port;
In response to a trace request with TTL = 1, a trace response generation unit that generates a trace response with the source MAC address of the trace request as a destination MAC address and includes the transfer information recorded in the transfer information recording unit in the trace response Function as a computer
The switch control means makes the computer function so as to send back a trace response from the port that has received the trace request.

  According to the communication apparatus program of the present invention, the trace request and the trace response are Ethernet OAM frames that are operation and maintenance management frames, the trace request is ETH-LTM, and the trace response is ETH-LTR. Is also preferable.

According to the present invention, there is provided a program for causing a computer mounted on a management device that detects a logical topology in a network to which a plurality of communication devices are connected to function.
Port trace transmission / reception means for transmitting a trace request including the TTL to the communication device and receiving a trace response each time the TTL is incremented by 1 from 1
Transfer information is acquired from the received trace response, and the computer functions as port topology detection means for deriving a port topology in the network device topology.

According to another embodiment of the management device program of the present invention,
Device trace transmission / reception means for transmitting a trace request including a TTL that is the maximum value in the network to the communication device and receiving a trace response from all of the communication devices;
It is also preferable to further cause the computer to function as device topology detection means for deriving the device topology of the network from the trace response.

  According to the topology detection method, communication device, management device, and program of the present invention, not only the device topology but also the port topology can be detected for the layer 2 network device managed only by the device MAC address.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a functional configuration diagram of the layer 2 network device and the management device according to the present invention.

  According to FIG. 2, the layer 2 network device 1 includes a plurality of ports 101, a switch control unit 102, a trace request determination unit 103, a trace response generation unit 104, and a transfer information recording unit 105. These functional units excluding the port 101 can also be realized by executing a program for causing a computer mounted on the layer 2 network device to function.

  The port 101 is a connection interface as hardware. Each port is arbitrarily assigned a port number (different from the TCP port number), and is connected to another communication device (layer 2 network device, management device or communication terminal) by wire.

  The switch control unit 102 relays a layer 2 frame between a plurality of ports. For example, it has the same function as the switching HUB. Here, when the switch control unit 102 receives a trace request from any of the ports, the switch control unit 102 notifies the trace request determination unit 103 of the trace request. The trace request is ETH-LTM in the Ethernet OAM frame that is an operation and maintenance management frame.

  The transfer information recording unit 105 records transfer information in which a port number and a transmission source MAC address are associated with each other. The forwarding information is referred to as FDB (Forwarding DataBase). For example, when the layer 2 network device A is connected to the port 1, the port number 1 and the MAC address A of the layer 2 network device A are recorded in association with each other.

  The trace request determination unit 103 determines whether or not TTL = 1 for the ETH-LTM notified from the switch control unit 102. TTL (Time To Live) means the lifetime of the packet. Each time the packet is relayed through the layer 2 network device, the TTL is decremented by one. The layer 2 network device that has received the frame with TTL = 1 discards the frame.

  According to the present invention, the trace request determination unit 103 notifies the trace response generation unit 104 of ETH-LTM with TTL = 1. On the other hand, ETH-LTMs other than TTL = 1 are notified to the switch control unit 102 and transferred to the next port based on the destination address.

  The trace response generation unit 104 generates a trace response with the transmission source MAC address as the destination MAC address for ETH-LTM with TTL = 1. The trace response is an ETH-LTR in an Ethernet OAM frame that is an operation and maintenance management frame. Here, according to the present invention, the FDB recorded in the transfer information recording unit 105 is included in the TLV (Time, Length and Value) of the ETH-LTR. Then, the ETH-LTR is notified to the switch control unit 102.

  The switch control unit 102 returns the ETH-LTR from the port that has received the ETH-LTM. Thereby, the management apparatus can receive the ETH-LTR and know the port topology based on the FDB.

  According to FIG. 2, the management device 2 includes a device trace transmission / reception unit 201, a device topology detection unit 202, a port trace transmission / reception unit 203, and a port topology detection unit 204. These functional units can also be realized by executing a program that causes a computer installed in the management apparatus to function.

  The device trace transmission / reception unit 201 transmits the ETH-LTM to the adjacent layer 2 network device. The ETH-LTM sets the destination address to unknown and includes the maximum value TTL in the network. On the other hand, the device trace transmission / reception unit 201 receives the ETH-LTR from all the layer 2 network devices in the network.

  The device topology detection unit 202 derives the device topology of the layer 2 network device connected to the network from the transmission source MAC address of the ETH-LTR.

  Each time the port trace transmission / reception unit 203 increments the TTL by 1, the port trace transmission / reception unit 203 transmits the ETH-LTM including the TTL to the adjacent layer 2 network device. Thereby, the ETH-LTR is received for each layer 2 network device.

  The port topology detection unit 204 acquires the FDB from the ETH-LTR and derives the port topology of the layer 2 network device connected to the network.

  FIG. 3 is a sequence diagram in the present invention.

  According to FIG. 3, it is assumed that the target network has layer 2 network devices A, B and C. The management device 2 is directly connected to the layer 2 network device A, and can communicate with the layer 2 network devices B and C via the layer 2 network device A. Each layer 2 network device has an FDB in which an input port is associated with a source MAC address.

  First, the management device 2 detects a device topology, that is, a connection form of devices in the network.

(S301) The management apparatus 2 first transmits a trace request (ETH-LTM) to the adjacent layer 2 network apparatus A. The ETH-LTM sets the destination address to unknown (unknown), for example, TTL = 255 (maximum value). As a result, the ETH-LTM is broadcast in the network and reaches the end layer 2 network device.
(S302) The layer 2 network device A confirms the TTL in ETH-LTM. Decrementing TTL by 1 gives 254, not 0. Therefore, the layer 2 network device A further broadcasts to the adjacent layer 2 network devices B and C.

(S303) The layer 2 network device A returns a trace response (ETH-LTR) to the management device 2 in response to the ETH-LTM. The source MAC address of the ETH-LTR is the device MAC address of the layer 2 network device A. Thereby, the management apparatus 2 can know the presence of the layer 2 network apparatus A.

(S304) The layer 2 network device B returns an ETH-LTR to the management device 2 in response to the ETH-LTM. The source MAC address of the ETH-LTR is the device MAC address of the layer 2 network device B. Thereby, the management apparatus 2 can know the presence of the layer 2 network apparatus B.
(S305) The layer 2 network device C also returns an ETH-LTR to the management device 2 as in S304.

(S306) The management device 2 can receive the ETH-LTR from all the layer 2 network devices connected to the network. Thereby, the management apparatus 2 can know the apparatus topology in the network, that is, the connection form of the apparatus MAC address.

  Next, the management apparatus 2 detects the port topology, that is, the connection form of the port MAC address in the apparatus topology.

(S311) First, the management apparatus 2 transmits a trace request (ETH-LTM) to the layer 2 network apparatus in which TTL = 1 based on the apparatus topology. Specifically, the management apparatus 2 transmits ETH-LTM with TTL = 1, with the destination address as the layer 2 network apparatus A.

(S312) The layer 2 network device A receives the ETH-LTM with TTL = 1. At this time, when TTL is decremented by 1, it becomes 0. Therefore, the layer 2 network device A generates a trace response (ETH-LTR). At this time, the FDB of the layer 2 network device A is added to the TLV of the ETH-LTR. Further, in the ETH-LTR, TTL = 1 is set, and the destination address is set in the management apparatus 2. Then, the layer 2 network device A returns the ETH-LTR to the management device 2. Thereby, the management apparatus 2 can know the connection port state for the layer 2 network apparatus A.

(S313) Next, the management apparatus 2 transmits ETH-LTM to the layer 2 network apparatus B in which TTL = 2 based on the apparatus topology. Specifically, the management apparatus 2 transmits ETH-LTM with TTL = 2, with the destination address as the layer 2 network apparatus B. When the layer 2 network device A receives the ETH-LTM with TTL = 2, the layer 2 network device A decrements the TTL by 1 and further transfers it to the layer 2 network device B.

(S314) The layer 2 network device B receives the ETH-LTM with TTL = 1. At this time, when TTL is decremented by 1, it becomes 0. Therefore, the layer 2 network device B generates an ETH-LTR. At this time, the FDB of the layer 2 network device B is added to the ETH-LTR. Further, in the ETH-LTR, TTL = 1 is set, and the destination address is set in the management apparatus 2. Then, the layer 2 network device B returns the ETH-LTR to the layer 2 network device A. The layer 2 network device A transfers the ETH-LTR to the management device 2. Thereby, the management apparatus 2 can know the transmission source MAC address for each port for the layer 2 network apparatus B.

(S315) The management apparatus 2 transmits an ETH-LTM in which TTL = 2 and the destination address is the layer 2 network apparatus C to the layer 2 network apparatus C via the layer 2 network apparatus A, similarly to S313. .

(S316) The layer 2 network device C transmits the ETH-LTR with TTL = 2 and the destination address as the management device 2 to the management device 2 via the layer 2 network device A, similarly to S314. The ETH-LTR includes the FDB of the layer 2 network device C.

  Thus, after that, the management device 2 transmits the ETH-LTM and receives the ETH-LTR from the layer 2 network device every time the TTL is incremented by 1 in accordance with the device topology. Get port information of network device.

(S317) The management device 2 receives the ETH-LTR from all the layer 2 network devices connected to the network. Thereby, the management apparatus 2 can know the port topology in the apparatus topology in the network, that is, the connection form of the port MAC address.

  As described above in detail, according to the topology detection method, communication device, management device and program of the present invention, not only the device topology but also the port topology for the layer 2 network device managed only by the device MAC address. Can also be detected.

  According to the various embodiments of the present invention described above, those skilled in the art can easily make various changes, modifications and omissions within the scope of the technical idea and the viewpoint of the present invention. The above description is merely an example, and is not intended to be restrictive. The invention is limited only as defined in the following claims and the equivalents thereto.

It is a sequence diagram of a path trace in the prior art. It is a functional block diagram of the layer 2 network apparatus and management apparatus in this invention. It is a sequence diagram in the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Layer 2 network apparatus 101 Port 102 Switch control part 103 Trace request determination part 104 Trace response generation part 105 Transfer information recording part 2 Management apparatus 201 Apparatus trace transmission / reception part 202 Apparatus topology detection part 203 Port trace transmission / reception part 204 Port topology detection part

Claims (10)

A topology detection method in a system having a plurality of communication devices that relay layer 2 frames between a plurality of ports and a management device that detects a logical topology of a network to which the communication devices are connected,
The communication device records transfer information in which a port number and a source MAC (Media Access Control) address are associated with each other,
A first step of transmitting a trace request including the TTL to the communication device each time the management device increments TTL (Time To Live) by 1 in order,
A second step in which the communication device returns a trace response including the transfer information to the management device in response to a trace request of TTL = 1;
A topology detection method comprising: a third step in which the management device acquires the transfer information from the received trace response and derives a port topology in the device topology of the network. The trace request and the trace response are Ethernet OAM (Operation Administration and Maintenance) frames that are operation and maintenance management frames.
The trace request is ETH-LTM (ETHernet Link Trace Massage),
The topology detection method according to claim 1, wherein the trace response is ETH-LTR (ETHernet Link Trace Reply). In a communication apparatus having a switch control means for relaying a layer 2 frame between a plurality of ports,
Transfer information recording means for recording transfer information in which a port number of a port through which the layer 2 frame is input and output and a source MAC address are associated;
Trace request determination means for determining whether or not TTL = 1 for the trace request received from the port;
In response to a trace request with TTL = 1, a trace response is generated with the source MAC address of the trace request as a destination MAC address, and the transfer information recorded in the transfer information recording means is included in the trace response. Response generating means,
The switch control means returns the trace response from the port that has received the trace request.   4. The trace request and the trace response are Ethernet OAM frames that are operation and maintenance management frames, the trace request is ETH-LTM, and the trace response is ETH-LTR. The communication apparatus as described in. A management device for detecting a logical topology in a network to which a plurality of communication devices according to claim 3 or 4 are connected,
Port trace transmission / reception means for transmitting the trace request including the TTL to the communication device and receiving the trace response each time the TTL is incremented by 1 from 1
And a port topology detection unit that obtains the transfer information from the received trace response and derives a port topology in the device topology of the network. Device trace transmission / reception means for transmitting the trace request including the TTL that is the maximum value in the network to the communication device and receiving a trace response from all of the communication devices;
6. The management apparatus according to claim 5, further comprising apparatus topology detection means for deriving an apparatus topology of the network from the trace response. A program for causing a computer mounted on a communication device having a plurality of ports to function, wherein the computer functions as a switch control unit that relays a layer 2 frame between ports.
Transfer information recording means for recording transfer information in which a port number and a source MAC address are associated with each other;
Trace request determination means for determining whether or not TTL = 1 for the trace request received from the port;
In response to a trace request with TTL = 1, a trace response is generated with the source MAC address of the trace request as a destination MAC address, and the transfer information recorded in the transfer information recording means is included in the trace response. Let the computer function as a response generator,
The program for a communication apparatus, wherein the switch control unit causes a computer to function so as to send back the trace response from a port that has received the trace request.   8. The trace request and the trace response are Ethernet OAM frames that are operation and maintenance management frames, the trace request is ETH-LTM, and the trace response is ETH-LTR. The communication device program described in 1. A program for causing a computer mounted on a management device for detecting a logical topology in a network to which a plurality of communication devices according to claim 3 or 4 are connected to function.
Port trace transmission / reception means for transmitting the trace request including the TTL to the communication device and receiving the trace response each time the TTL is incremented by 1 from 1
A program for a management apparatus that acquires the transfer information from the received trace response and causes a computer to function as port topology detection means for deriving a port topology in the apparatus topology of the network. Device trace transmission / reception means for transmitting the trace request including the TTL that is the maximum value in the network to the communication device and receiving a trace response from all of the communication devices;
10. The management device program according to claim 9, further causing a computer to function as device topology detection means for deriving a device topology of the network from the trace response.

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