KR100798995B1 - Method of trap message transmitting by TCP mode base on SNMP - Google Patents

Abstract

The present invention relates to a method for an agent to transmit a trap message in an SNMP network. In particular, the method for transmitting a trap message using the TCP method according to the present invention may occur in a specific situation in which an agent of an SNMP network needs to report to an administrator. Generating a trap message; Transmitting the generated trap message to an administrator by configuring a local network frame using a TCP method; Waiting for a response message to the transmitted message for a predetermined time; If the response message has not been received for the predetermined time period, retransmitting the local network frame in which the trap message is configured.

According to the present invention, it is possible to reliably and accurately report the situation to the administrator by using the TCP method when the SNMP agent transmits the trap message, it is possible to grasp the situation that the message is not delivered so that unnecessary messages are not transmitted. The effect of reducing the load on the agent is expected.

SNMP, UDP, TCP, Trap

Description

Method of trap message transmitting by TCP mode base on SNMP}

1 is a block diagram showing a message transmission and reception flow of a conventional SNMP network.

Figure 2 is a block diagram showing a frame configuration applying the UDP of the conventional SNMP network.

3 is a block diagram illustrating a Trap message configuration of the SNMP network of FIG. 2.

4 is a block diagram illustrating a frame structure used in a trap message transmission method using an SNMP-based TCP method according to an embodiment of the present invention.

5 is a flowchart illustrating a message transmission and reception method of a data transmission method using TCP according to an embodiment of the present invention.

The present invention relates to a trap message indicating a failure in a simple network management protocol (SNMP). In particular, the present invention generates a trap message by transmitting a message using a TCP scheme to provide reliability of the trap message. The present invention relates to a failure message transmission method using the SNMP-based TCP method, which can safely and reliably transmit data indicating a specific situation.

SNMP is a protocol that monitors and communicates network management and network devices and their operations. Basically, the agent defines the message format for sending and receiving messages between the manager and the agent. Basically, the agent responds to the manager's question. This protocol informs the administrator when it occurs and sends necessary information together.

SNMP sends and receives messages using protocol data unit (PDU), which is divided into five types.

1 is a block diagram showing a message transmission and reception flow of a conventional SNMP network.

Referring to FIG. 1, among the messages exchanged between the SNMP manager 10 and the agent 20, first, a GetRequest message is for the administrator to read a value of a specific object (object instance) and requests the agent for a specific object value. Accordingly, the agent transmits the value information of the object requested by the administrator using the GetResponse message.

Also, using GetNextRequest message, the administrator can request the next index value of the designated object value or the next index value if the specified object is an index table. The agent transmits the information requested by the manager to the GetResponse message.

And, using SetRequest message, the administrator requests the agent to change the object value, and the response is also the GetResponse message.

Finally, the agent uses the Trap message to notify the manager when a special situation occurs.

In other words, there are two message formats that the agent sends to the manager in SNMP, using only GetResponse to respond to the manager's request and Trap message to notify of the failure.

In particular, in a situation in which the agent informs the administrator by using the trap message for the occurrence of a failure, a link-down trap message transmitted when a defect occurs in an agent network interface and a link up message transmitted during normal interface recovery -up) Trap message, cold start trap message sent to the manager when the agent starts, a warm start trap message that occurs when SNMP initializes its tables, the community name that the agent has configured the device, An authentication failure Trap message occurs when an SNMP request with a mismatched name is received. If the agent itself cannot communicate with an EGP neighbor, it generates a loss of EGP neighbor Trap message. If a specific situation occurs other than the above (enterpriseSpecific), generate a trap message It is good.

As described above, when a message is exchanged between the manager 10 and the agent 20, a PDU method is used. The PDU method has a connectionless characteristic and transmits a message regardless of whether a connection is made with a counterpart. There is a characteristic.

The configuration of the Trap message to which the UDP (User Datagram Protocol) is applied is as follows.

FIG. 2 is a block diagram illustrating a frame configuration using UDP of a conventional SNMP network, and FIG. 3 is a block diagram illustrating a trap message configuration of the SNMP network of FIG. 2.

Referring to FIG. 2, a UDP-applied frame in an SNMP network includes local network header information, IP header information, and UDP header as header information. It is composed of a local network tailer (Local Network Tailer), and the UDP header contains data such as a transmission destination port, a destination port, a length, and a checksum.

In addition, referring to FIGS. 2 and 3, a Trap message transmitted with the above UDP header is generated and transmitted in a SNMP PDU portion from UDP data composed of a version number and an SNMP PDU portion of a community string. Referring to FIG. 3, PDU type information, an enterprise, an agent address, a trap type, a special code, a type stamp, and a fixed variable are included.

When the trap message is transmitted from the agent 20 to the manager 10 as shown in FIG. 1, the agent 20 recognizes that the trap message transmitted once has been processed without any step of transmitting a response thereto. Monitor and continue to report.

As described above, in the conventional Trap message generation and transmission using the UDP method, there is a lack of reliability in correctly transmitting a situation occurring in an agent to an administrator. That is, even if the link with the manager is not connected or the trap message sent due to an error is not delivered to the manager, the agent cannot receive the agent status message because there is no way for the agent to check it. Even though the message is not transmitted, another Trap message is continuously transmitted, thus causing a problem in that the bandwidth is more than necessary.

In order to solve the above problems, the present invention uses a TCP method having a connection-orient characteristic as an alternative to the UDP method, so that the agent can check whether the trap message sent from the agent is received. Its purpose is to provide a Trap message transmission method using the TCP method that can deliver a report on the situation to the manager more reliably and accurately.

Trap message transmission method using the TCP method according to the present invention,

Generating a trap message by generating a specific situation in which an agent of an SNMP network needs to report to an administrator;

Transmitting the generated trap message to an administrator by configuring a local network frame using a TCP method;

Waiting for a response message to the transmitted message for a predetermined time;

Retransmitting a local network frame including the trap message at a predetermined time interval if the response message is not received during the predetermined time; If it does not continue to receive the response message, it is determined that the link error, characterized in that it comprises the step of waiting without sending any further message until the link is restored.

Preferably, when the response message is received within a predetermined time, the next trap message is characterized in that it further comprises the step of configuring and transmitting the local network frame by the TCP method.

The trap message transmission method using the TCP method according to the present invention as described above with reference to the accompanying drawings as follows.

4 is a block diagram illustrating a frame structure used in a trap message transmission method using an SNMP-based TCP method according to an embodiment of the present invention.

Referring to FIG. 4, when a situation such as authentication failure, link error or recovery, agent start, etc. occurs in the agent as described above, a trap message is generated, and a local network frame is configured as shown in FIG. 4 to transmit it. It is.

That is, it is the same as the network frame using the UDP method, but includes TCP header information such as a transmission destination port, a destination port, a sequence number, a window length, a checksum, an emergency pointer and a header length, and a response using a TCP header rather than a UDP header. Configure and transmit local network frames.

Transmitting and receiving a local network frame constructed using the above TCP method is as shown in FIG. 5. Of course, according to the present invention, the Trap message transmitted between the manager and the agent is also transmitted and received in the order shown in FIG. 5.

5 is a flowchart illustrating a message transmission and reception method of a data transmission method using TCP according to an embodiment of the present invention.                     

Referring to FIG. 5, the sender 30 belongs to the agent and the receiver 40 belongs to the manager based on the Trap message transmission and reception compared to the SNMP network. The sender 30 sends data 1 to the receiver 40. When transmitting (S101), the receiver 40 transmits a response message such as a data1 reception notification thereto (S102).

The sender 30 transmits data 2, which is the next data, only after receiving the reception notification message (S103). At this time, if the data is not transmitted to the receiver 40 because an error occurs in the link, the receiver 40 does not send the reception notification message. It is not (S104).

Therefore, the sender 30 waiting for the reception notification message for the data 2 waits for a predetermined time, determines that the data 2 has not been properly transmitted, and retransmits it (S105), and the data 2 reception notification message comes from the receiver 40. Until (S106), continue to be retransmitted at intervals for a certain time.

The retransmission is repeated for a predetermined number of times, and if there is no response message continuously, it is determined as a link error and waits without transmitting any more messages until the link is restored. At this time, it should be implemented to receive information about link recovery from administrator or user separately.

In this way, if the Trap message is transmitted using TCP method, the agent can accurately report the status to the administrator, and when the message is not transmitted due to a link error, the agent waits until the link is recovered and transmits the Trap message. It also has the effect of reducing the load on the agent, as there is no need to keep sending trap messages that are not delivered.                     

For example, when the agent transmits a trap message using the TCP method, if the SNMP agent puts 'poseid' in the community name that configures the system, and the administrator requests an object of the community 'public', the agent fails authentication. Because the situation of occurs, it generates a trap message.

When the message is composed and transmitted in a frame by the TCP method, the administrator transmits a response message to the agent accordingly.

If the response message is not received from the agent for a certain time, the agent determines that the trap message has not been transmitted and retransmits the message.

In addition, the load is reduced because other trap messages are not sent until a response message is received.

As described above, the Trap message transmission method using the TCP method according to the present invention, unlike the conventional method that simply delivers the Trap message to the administrator using the UDP method, the SNMP agent uses the TCP method to transmit the trap message. When sending, the agent can accurately report the status to the administrator.When the message cannot be transmitted due to a link error, the agent waits until the link is restored and sends a trap message. There is no effect of reducing the load on the agent.

Claims (4)

Generating a trap message by generating a specific situation in which an agent of an SNMP network needs to report to an administrator; Transmitting the generated trap message to an administrator by configuring a local network frame using a TCP method; Waiting for a response message to the transmitted message for a predetermined time; Retransmitting a local network frame including the trap message at a predetermined time interval if the response message is not received during the predetermined time; If it does not continue to receive the response message, it is determined that the link error, and waiting for the link is restored without sending any further message Trap message transmission method using the TCP method. The method as claimed in claim 1, further comprising: when the response message is received within a predetermined time, constructing and transmitting a next trap message in a local network frame using a TCP scheme. The method of claim 2, The local network frame includes a local network header, an IP header, a TCP header, an SNMP message, a local network taylor, wherein the TCP header includes a destination port, a destination port, a sequence number, a window length, a checksum, an emergency pointer and a header length, Trap message transmission method using the TCP method, including the response information. In the trap message transmission system using the SNMP-based TCP method, An administrator for managing the network and sending a response message upon receipt of a trap message; When a specific situation that needs to be reported to the administrator occurs, a trap message is generated, and the generated trap message is configured as a local network frame by a TCP method and transmitted to the administrator, and a response message has not been received for a predetermined time. In this case, the local network frame is retransmitted a predetermined number of times at regular intervals, and if it does not continue to receive a response message, SNMP is determined to be a link error and waits without transmitting any more messages until the link is restored. Trap message transmission system using TCP based method.

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