WO2009012684A1

WO2009012684A1 - A method, system and function entity for achieving the echo function of the bfd mechanism

Info

Publication number: WO2009012684A1
Application number: PCT/CN2008/071542
Authority: WO
Inventors: Lina Wu; Wei Zhang; Yuting Wang; Zuliang Wang; Peng Wang
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-07-20
Filing date: 2008-07-03
Publication date: 2009-01-29
Also published as: CN101087211B; CN101087211A

Abstract

A method, system and function entity for achieving the echo function of the BFD mechanism includes: setting the source address and the destination address in the IP head of an echo packet to be the IP address of the port which sends the echo packet, the identification parameter of the echo packet is also setted, and then sending the echo packet to the far end; after receiving the echo packet, the far end analyzes and processes the echo packet according to the identification parameter. The echo function of the bidirectional forwarding detection mechanism is simply and accurately achieved, and link faults are discovered in time.

Description

Method, system and functional entity for realizing echo function in BFD mechanism

[1] Technical field

[2] The present invention relates to the field of communications technologies, and in particular, to a method, system, and functional entity for implementing an echo function in a BFD mechanism.

[3] Background of the invention

[4] BFD (Bidirectional Forwarding Detection) is a fast detection mechanism that enables fault detection on any type of channel between systems, including direct physical links, virtual circuits, tunnels, multi-hop routing channels, and Indirect channels, etc.

[5] BFD can be abstracted into a simple service, which provides services such as detecting network reachability and providing reachability status information (UP/DOWN information) for the application layer.

[6] BFD is similar to the "Hello" protocol. After a BFD session is established, the two parties periodically send BFD packets to the peer. The format of the BFD packets is as shown in Figure 1. A peer BFD can also periodically detect the arrival of the other party's packets on the BFD-enabled link. If the BFD packet from the remote end is not received within a certain interval, the network can be considered faulty. The purpose of rapid fault detection.

[7] BFD can work in asynchronous mode, or in query mode. In the asynchronous mode, after the agreement is reached between the systems, the BFD control packets are periodically sent to each other. If a system does not receive the BFD control packet from the remote end within the agreed detection time, the system announces the session as In the query mode, it is assumed that each system after the agreement has an independent method to confirm that it is connected to other systems, so that once a BFD session is established, the system stops sending BFD control messages unless If the system needs to explicitly verify the connectivity, the system sends a short sequence of BFD control packets. If the returned packets are not received within the agreed detection interval, the system announces that the session is Down. In response to the message, the agreement remains silent again.

In the asynchronous detection mode, the two routers (R _OU terA, Router B) send BFD control packets to the remote end. The situation is as shown in Figure 2 to maintain the BFD detection. When the network traffic is relatively large, the BFD fast asynchronous detection packets of large traffic will impact the smoothness of the network. If the query mode is used for detection, the system cannot detect the link. The failure caused the loss of data.

At present, in view of the above defects of BFD, an evasive method is proposed to realize the ECHO (echo) function of auxiliary detection. The ECHO function uses a short ECHO message and a method in which the remote router does not process the message, and sends a series of BFDs in the local system.

ECHO messages, the remote system loops back through its forwarding channel, reducing the load on the network and the router CPU.

In the process of implementing the present invention, the inventors have found that the prior art does not explicitly indicate how to implement the E CHO function, and thus, it is possible to cause the skilled person to use the ECHO function correctly. Summary of the invention

The main technical problem to be solved by the embodiments of the present invention is to provide a method, system and functional entity for implementing the echo function in the BFD mechanism, thereby ensuring the correct use of the echo function in the BFD mechanism.

An embodiment of the present invention provides a method for implementing an echo function in a BFD mechanism, where the method includes: sending an echo message to a remote end, where a source address and a destination address in the IP header of the echo message are sent echoes IP address of the interface of the packet;

The echo message is analyzed and processed according to the authentication parameter in the echo message of the remote loopback. The embodiment of the present invention further provides a system for implementing an echo function in a BFD mechanism, where the system includes a first functional entity and a second functional entity, where:

The first function entity is configured to send the echo message to the second function entity, where the source end and the destination end address in the IP header of the echo message are the IP address of the interface that sends the echo message;

a second function entity, configured to receive an echo message sent by the first function entity, and loop the received echo message back to the first functional entity;

The first functional entity is further configured to receive an echo message of the loopback of the second functional entity, and analyze and process the packet according to the authentication parameter in the packet.

An embodiment of the present invention further provides a functional entity, where the functional entity includes:

The sending module is configured to set the source and destination addresses in the IP header of the echo packet to the IP address of the interface that sends the echo packet, and send the configured echo message to other functional entities on the network side. The processing module is configured to receive an echo message of the loopback of other functional entities on the network side, and analyze and process the packet according to the authentication parameter in the packet. [23] The embodiment of the present invention further provides a functional entity, where the functional entity includes a receiving module, a redirecting module, and a loopback module, where:

[24] The receiving module is configured to receive an echo message sent by the network side functional entity, and trigger the redirection module after receiving the echo message;

[25] The redirection module is configured to: when triggered by the receiving module, start an internet protocol message protocol redirection function, and perform a redirection operation on the echo message received by the receiving module;

[26] The loopback module is configured to loop back the echo packets processed by the redirection module to the network side functional entity.

[27] The embodiment of the present invention further provides a functional entity, where the functional entity includes a receiving module, a first determining triggering module, a second determining triggering module, and an echo function starting module, where:

[28] a receiving module, configured to receive a packet sent by a network side functional entity;

[29] The first determining triggering module is configured to determine whether the packet received by the receiving module is an echo function negotiation packet, and trigger the second determining triggering module after determining that the packet is an echo function negotiation packet;

[30] The second judgment triggering module is configured to: determine, by the first judgment triggering module, whether the echo function negotiation packet determined by the first judgment triggering module satisfies the filtering rule, and the negotiation message satisfies the rule in the echo function. , triggering the echo function to activate the module;

[31] The echo function startup module is configured to start the echo function in the bidirectional forwarding detection mechanism under the trigger of the first judgment trigger module.

[32] According to the technical solution provided by the foregoing embodiment of the present invention, in the embodiment of the present invention, the source end and the destination end address in the IP header of the echo packet are set as the IP address of the interface that sends the echo packet, and Set the authentication parameters of the echo packets, and send the echo packets that have been set to the remote end. Receive the echo packets of the remote loopback, and analyze and process the packets based on the authentication parameters in the packets. The echo function in the two-way forwarding detection mechanism is correctly implemented, and the detection of the link failure is ensured.

[33] BRIEF DESCRIPTION OF THE DRAWINGS

[34] Figure 1 shows the format of a BFD packet in the prior art;

[35] FIG. 2 is a schematic diagram of a detection process of BFD in the prior art;

FIG. 3 is a schematic diagram of a method for implementing a BFD ECHO function according to Embodiment 1 of the present invention; FIG.

4 is a flowchart of a specific implementation of a method according to Embodiment 1 of the present invention;

FIG. 5 is a flowchart of determining an ECHO function startup according to Embodiment 1 of the present invention; FIG. 6 is a schematic structural diagram 1 of a system for implementing a BFD ECHO function according to Embodiment 2 of the present invention;

FIG. 7 is a schematic structural diagram 2 of a system for implementing a BFD ECHO function according to Embodiment 2 of the present invention; FIG.

FIG. 8 is a schematic structural diagram of a functional entity according to Embodiment 3 of the present invention; FIG.

FIG. 9 is a schematic structural diagram of a functional entity according to Embodiment 4 of the present invention; FIG.

FIG. 10 is a schematic structural diagram of a functional entity according to Embodiment 5 of the present invention.

[44] Mode for carrying out the invention

The present invention will be further described in detail below with reference to the accompanying drawings.

[46] The first embodiment of the present invention provides a method for implementing a BFD (bidirectional forwarding detection) ECHO (echo) function, in which the IP header address and the authentication parameter of the ECHO packet can be set, and the setting is completed. The ECHO packet is sent to the remote end, and then the remote loopback ECHO packet is received, and the packet is analyzed and processed according to the authentication parameter in the packet, thereby simply and correctly implementing the BFD ECHO auxiliary detection function to ensure The discovery of link failures.

[47] It should be noted that BFD

The ECHO packet actually detects the remote forwarding channel. The packet does not need to be uploaded to the remote BFD module. The remote forwarding layer directly loops the packet back to the sending end. The ECHO packet is actually sent. The origin of the ECHO message is detected.

Based on the above principle, in the embodiment of the present invention, the originating end uniformly sets the source end (ie, the transmitting end) and the destination end (ie, the far end) address in the IP head of the ECHO packet to the IP address of the interface that sends the ECHO packet, so that The packet is sent to the remote end. The destination address is not matched with the remote address. This triggers the remote ICMP (Internet Control Message Protocol) redirection function and loops the ECHO packet back to the packet originating end.

After the ECHO packet is returned from the remote loop, the originator needs to separate the ECHO packet into the correct BFD session according to the information in the packet. Because the association between BFD packets and sessions is session-based.

Based on this, the embodiment of the present invention performs special processing on the issued ECHO message based on the original message format, and the session's My Discriminator and Your

The position of the Discriminator in the message is interchanged. In this way, after receiving the ECHO message returned by the loopback, the sending end will process the packet as the remote end, and maintain the normal detection of the sending end. On The implementation process of the principle is shown in Figure 3.

In the embodiment of the present invention, the sending end may be Router A (Router A), and the remote end may be Router B.

(Router B).

[51] As shown in FIG. 4, the implementation of the first embodiment of the present invention implements BFD

The processing flow of the method of the ECHO function may specifically include:

[52] Step 41. Determine whether to activate the ECHO auxiliary detection function.

In the embodiment of the present invention, the packet sent by the remote end may be filtered during the session establishment phase, so that the ECHO function is enabled only on a specific link, and the detection modes are more flexibly used. Achieve the best detection results.

[54] In the following, the ACL (Access Control List) mechanism is used as an example to describe the process in detail. As shown in FIG. 5, the process may specifically include:

[55] Step 41A: Receive the negotiation packet sent by the remote end.

[56] Step 41B: Determine whether the received packet is an ECHO negotiation packet.

[57] If the received message is an ECHO negotiation message, step 41C is performed;

[58] If the received message is not an ECHO negotiation message, asynchronous or query detection negotiation is performed. Since this process is no longer covered by the present invention, it is not mentioned here.

[59] Step 41C: Determine whether the received ECHO negotiation packet meets the ACL rule.

[60] After determining that the received packet is an ECHO negotiation packet, it is determined whether the ECHO negotiation packet satisfies the ACL rule.

[61] The above ACL rule can be enforced by permit I deny

A series of ordered rules consisting of statements based on the source address, destination address, port number, etc. of the packet.

[62] According to the purpose of ACL, ACLs can be divided into three types, as shown in the following table.

[63]

ACL type number range

Interface-based ACL 1000~ 1999 Basic ACL 2000~2999 Advanced ACL 3000~3999 [64] The ACL number ranges from 2000 to 2999, which is the Basic ACL. Basic

The ACL uses the source address information as an element that defines the ACL rule.

[65] The basic ACL rule can filter the packets based on the source address information. Therefore, by configuring the corresponding ACL rules, you can use the ECHO function to detect only the specific links.

[66] Therefore, if the received ECHO negotiation message satisfies the ACL rule, step 41D is performed;

[67] If the received ECHO negotiation packet does not satisfy the ACL rule, asynchronous or query detection negotiation is performed.

[68] It should be noted that, in the embodiment of the present invention, the ACH rule is not limited to the received ECH.

If the negotiation packet is filtered, the ECHO negotiation packet can be filtered by other rules to implement detection only by using the ECHO function for a specific link.

[69] Step 41D, Start ECHO detection function.

[70] If the received ECHO negotiation packet satisfies the ACL rule, the ECHO detection function is enabled, and step 42 is performed.

[71] Step 42: Set the IP header address and authentication parameters of the ECHO packet, and send the configured ECHO packet to the remote end.

[72] In view of the principle shown in FIG. 3, the source end (ie, the sender end) and the destination end (ie, the far end) address in the IP header address of the ECHO packet are uniformly set to the interface IP address of the ECHO packet. And the positions of the My Discriminator and Your Discriminator parameters in the ECHO message are exchanged.

[73] After completing the above settings, send ECHO packets to RouterB.

In the embodiment of the present invention, the format of the ECHO packet is not separately designed, and only the existing BFD control packet format is modified to meet the needs of the ECHO detection, thereby reducing the impact on the existing process and reducing the protocol implementation. the complexity.

[75] Step 43: Remotely loop back ECHO messages.

[76] After receiving the ECHO packet sent by RouterA, RouterB does not process the ECHO packet. It only triggers the ICMP redirection function, redirects the ECHO packet, and sends the ECHO packet at the forwarding level. Wenhuan returns to RouterA.

[77] Step 44: Receive an ECHO packet of the remote loopback, and analyze and process the packet according to the authentication parameter in the packet.

[78] Router A receives the ECHO packet from Router B and obtains the ECHO packet. The Discriminator parameter is used to analyze and process the packet according to the parameter.

[79] Due to My Discriminator and Your in the ECHO message

The position of the discriminator parameter has been changed. Therefore, Router A considers the packet sent by Router B as the packet to analyze whether the link is faulty, thus maintaining the normal detection of Router A.

[80] The process of analyzing the received ECHO packet in this step may be: according to the authentication parameter in the packet, the session to which the packet belongs may be determined, and then the session to which the packet belongs may be determined to be a normal state. Further, it can be determined whether the link used by the session is in a normal state.

[81] In the actual application, if the local system (such as RouterA) does not receive any consecutive ECHO packets within the specified time interval, the session to which the ECHO message belongs is declared Down. The number of specified diurnal and ECHO messages mentioned above may be determined by the local system (such as Ro uterA) and the remote system (such as Router B) at the beginning of the session establishment.

The implementation of the _BFD provided by the embodiment of the present invention

The method of the ECHO function can be used together with the two existing detection modes of the BFD. This method can also be used instead of the detection task of the BFD control packet. This can reduce the transmission period of the control packet (in asynchronous mode) or completely cancel the BFD. Control message (in query mode).

[83] In view of the above implementation of the embodiment of the present invention, the implementation of BFD

Specific and objective technical features of the method of the ECHO function, the implementation of the BF provided by the embodiment of the present invention

D

The ECHO function method can also be used as a link fault detection method and becomes the object of patent law protection. In a specific application process, the BFD can be implemented according to the embodiment of the present invention.

The specific implementation process of the method of the ECHO function is performed, and the ECHO packet of the remote loopback is received, and then the transmission link that the session to which the ECHO packet belongs is determined to be in a normal state, and the transmission link is found to be faulty. Hey, report the situation.

[84] It should be noted that the foregoing process is a preferred solution for implementing the method in the embodiment of the present invention. In a specific application process, step 41 may be omitted, and step 42 may be directly performed, and whether the ECHO function is enabled on a specific link is not performed. Judgment. In addition, you can also not change My in the specific application process.

Discriminator and your mouth

The location of the discriminator parameter is different from the port number of the common BFD packet. (The port number of the ECHO packet is 3785, and the port number of the common BFD packet is 3784.) The packet is received according to the received packet, and the received packet is the ECHO packet.

The discriminator parameter is used to find the local discriminator parameter of the common BFD packet, and then determine the authentication parameter to be obtained, and analyze the packet according to the authentication parameter to determine whether the link is faulty. .

The method for implementing the BFD ECHO function provided by the embodiment of the present invention clarifies the BFD

The detection mechanism of the ECHO function, and provides a simple judgment mechanism, which makes it possible to use the ECHO function only on a specific link, thereby more flexibly using various detection modes and solving complex networking requirements. A system for implementing a BFD (Bidirectional Forwarding Detection) ECHO (Echo) function is provided, the system comprising a first functional entity and a second functional entity, wherein:

[87] 1) The first functional entity is configured to set the source and destination addresses in the IP header of the ECHO packet to the IP address of the interface that sends the echo message, and set the authentication parameter of the ECHO packet, and set the The completed ECH 0 packet is sent to the second functional entity. The first functional entity is further configured to receive the ECHO packet that is looped back by the second functional entity, and analyze and process the ECHO packet according to the authentication parameter in the ECHO packet. .

[88] The first functional entity may specifically include:

[89] A. Set the sending module, which is used to set the source and destination addresses in the IP header of the echo packet to the IP address of the interface that sends the echo message, and set the authentication parameters of the echo message, and complete the setting. The ECHO message is sent to the second functional entity in the system.

[90] Setting the sending module can include:

[91] Al, setting unit, used to set the source and destination addresses in the IP header of the echo packet to the IP address of the interface that sends the echo message, and the authentication parameter of the echo message.

[92] The specific operation procedure of the setting unit can be:

[93] The address of the source (ie, the sender) and the destination (that is, the remote) in the IP header address of the ECHO packet are uniformly set to the IP address of the interface that sends the ECHO packet.

[94] Interchange the positions of the My Discriminator and Your Discriminator parameters in the ECHO message.

[95] A2. The sending unit is configured to send the ECHO message that is set by the setting unit to the second functional entity in the system. [96] B. An analysis processing module, configured to receive an ECHO message of a loopback of a second functional entity in the system, and according to E

The authentication parameters in the CHO message analyze and process the ECHO message.

[97] The analysis processing module may specifically include:

[98] The receiving unit is configured to receive an ECHO packet that is looped back by the second functional entity in the system.

[99] The process of analyzing and processing the received ECHO packet by the analysis processing module may be: according to the authentication parameter in the packet, the session to which the packet belongs may be determined, and then the session to which the packet belongs may be determined to be a normal state. Further, it can be determined whether the link used by the session is in a normal state.

In the embodiment of the present invention, the first functional entity may be a router or other functional entity.

[101] 2) The second function entity is configured to receive the echo message sent by the first function entity, and loop back the received echo message to the first functional entity.

[102] The second functional entity triggers ICMP after receiving the ECHO packet sent by the first functional entity in the system.

(Internet Control Message Protocol) The redirection function loops the received ECHO packet back to the first functional entity. The second functional entity may include a receiving module, a redirection module, and a loopback module, where: 104: C. The receiving module is configured to receive an ECHO packet sent by the first functional entity in the system, and receive the E

After the CHO message, the redirection module is triggered.

The D.Redirecting module is configured to enable the ICMP redirection function to perform the redirection operation on the ECHO packet received by the receiving module.

106. E. The loopback module is configured to loop back the echo message processed by the redirection module to the first functional entity in the system.

In the embodiment of the present invention, the second functional entity may be a router or other functional entity.

In order to perform the ECHO function only for a specific link, the system provided by the embodiment of the present invention may further include: 109) 3) The third function entity is configured to receive the packet sent by the network side, and determine whether the received packet is The rule is satisfied; when the received message satisfies the rule, the first functional entity is triggered.

The third functional entity may specifically include a receiving module, a first determining triggering module, a second determining triggering module, and a first functional entity starting module, where:

111. F. The receiving module is configured to receive a packet sent by a network side functional entity.

The first judgment triggering module is configured to determine whether the packet received by the receiving module is an ECHO function negotiation message, and trigger the second judgment triggering module after determining that the message is an ECHO function negotiation message. [113] If the first judgment triggering module determines that the message received by the receiving module is not an ECHO function negotiation message, it is regarded as an invalid message and is not processed.

[114] H. The second judgment triggering module is configured to determine, by the first judgment triggering module, whether the ECHO function negotiation packet determined by the first judgment triggering module meets the filtering rule, and the ECHO function negotiation packet satisfies the rule.吋, trigger the first functional entity to start the module.

[115] If the second judgment triggering module determines that the ECHO function negotiation message determined by the first judgment triggering module does not meet the filtering rule, it is regarded as an invalid message and is not processed.

[116] The second judgment triggering module may specifically adopt an ACL (Access Control List) mechanism as its filtering rule, and set the filtering rule of the ACL at the beginning of the network system construction. The embodiment of the present invention may also filter the received message by using other similar rules or mechanisms.

[117] I. The first functional entity starting module is configured to start the first functional entity in the system under the trigger of the second determining triggering module.

[118] Further, in the system provided by the embodiment of the present invention, the third functional entity may be independently disposed in the system, or may be disposed in other functional entities in the system, for example, in the first functional entity, thereby The first functional entity has the specific operational functions of the third functional entity.

[119] The implementation of the BFD provided by the embodiment of the present invention

A schematic diagram of a specific implementation structure of the ECHO function system is shown in FIG. 6 or FIG.

[120] The system for implementing the BFD ECHO function provided by the embodiment of the present invention clarifies the BFD

The detection mechanism of the ECHO function, and provides a simple mechanism to enable the use of E CHO functions only on specific links, thereby making it more flexible to use various detection modes to solve complex networking requirements.

[121] The third embodiment of the present invention provides a functional entity, which is used to set the source and destination addresses in the IP header of the ECHO packet to the IP address of the interface that sends the ECHO packet, and set the ECHO report. The authentication parameter of the text, and the set ECHO message is sent to other functional entities on the network side; the functional entity can also be used to receive the ECHO message looped back by other functional entities on the network side, according to the authentication parameter in the ECHO message. , Analyze and process ECHO messages. As shown in FIG. 8, the functional entity may specifically include:

[122] J. The sending module is configured to set the source and destination addresses in the IP header of the ECHO packet to the IP address of the interface that sends the E CHO packet, and set the authentication parameter of the ECHO packet, and set the Completed E The CHO message is sent to other functional entities on the network side.

[123] Setting the sending module can include:

[124], the setting unit is configured to set the source and destination addresses in the IP header of the ECHO packet to the IP address of the interface that sends the ECHO packet, and set the authentication parameter of the ECHO packet.

[125] The specific operation procedure of the setting unit can be:

[126] The address of the source (ie, the sender) and the destination (that is, the remote) in the IP header address of the ECHO packet are uniformly set to the IP address of the interface that sends the ECHO packet.

[127] Change the positions of the My Discriminator and Your Discriminator parameters in the ECHO message.

[128] J2. The sending unit is configured to send the ECHO message that is set by the setting unit to other functional entities on the network side.

[129] K, an analysis processing module, configured to receive ECHO messages looped back by other functional entities on the network side, and according to E

[130] The analysis processing module may specifically include:

[131] Kl, receiving unit, configured to receive ECHO packets looped back by other functional entities on the network side.

[132] The process of analyzing and processing the received ECHO packet by the analysis processing module may be: according to the authentication parameter in the packet, the session to which the packet belongs may be determined, and then the session to which the packet belongs may be determined to be a normal state. Further, it can be determined whether the link used by the session is in a normal state.

The functional entity provided by the embodiment of the present invention may be a router or other functional entity.

[134] Embodiments of the present invention provide a functional entity that clarifies BFD

The detection mechanism of the ECHO function, through the analysis and processing of the identification parameters in the ECHO message of the loopback, thereby determining whether the transmission link is faulty or not.

The embodiment of the present invention provides a functional entity, which is configured to trigger an ICMP redirection function after receiving an ECHO packet sent by another functional entity on the network side, and loop back the received ECHO packet to the network side. Functional entity. As shown in FIG. 9, the functional entity may specifically include a receiving module, a redirecting module, and a loopback module, where:

[136] L. The receiving module is configured to receive an ECHO packet sent by another functional entity on the network side, and receive the E

After the CHO message, the redirection module is triggered.

[137] M, redirection module, used to trigger ICMP redirection function under the trigger of the receiving module, The ECHO packet received by the module is redirected.

[138] N. The loopback module is used to loop back the echo packets processed by the redirection module to other functional entities on the network side.

The functional entity provided by the embodiment of the present invention may specifically be a router or other functional entity.

[140] The functional entity provided by the embodiment of the present invention clarifies the BFD

The detection mechanism of the ECHO function is used to determine whether the transmission link is faulty or not.

The ninth embodiment of the present invention provides a functional entity, which is configured to receive a packet sent by the network, determine whether the received packet satisfies the rule, and trigger the ECHO function if the received packet satisfies the rule. . As shown in FIG. 10, the functional entity includes a receiving module, a first determining triggering module, a second determining triggering module, and an echo function starting module, where:

[142] 0. The receiving module is configured to receive a packet sent by a network side functional entity.

[143] P. The first judgment triggering module is configured to determine whether the packet received by the receiving module is an echo function negotiation message, and trigger the second judgment triggering module after determining that the packet is an echo function negotiation message.

[144] If the first judgment triggering module determines that the packet received by the receiving module is not an ECHO function negotiation message, it is regarded as an invalid message and is not processed.

[145] The second determining triggering module is configured to determine, by the first determining triggering module, whether the echo function negotiation packet determined by the first determining triggering module meets the filtering rule, and the echoing function negotiation message is satisfied. Rule 吋, triggers the echo function to start the module.

[146] If the second judgment triggering module determines that the ECHO function negotiation packet determined by the first judgment triggering module does not meet the filtering rule, it is regarded as an invalid packet and is not processed.

[147] The second judgment triggering module may specifically adopt an ACL (Access Control List) mechanism as its filtering rule, and set the filtering rule of the ACL at the beginning of the network system construction. The embodiment of the present invention may also filter the received message by using other similar rules or mechanisms.

[148] R, echo function starting module, used to start BFD under the trigger of the first judgment trigger module

ECHO function.

[149] Further, the functional entity provided by the embodiment of the present invention may be independently set on the network side or in other functional entities on the network side, so that other functional entities on the network side have the specific operations of the functional entity. Features. The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed by the present invention. Alternatives are intended to be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

Claim

[1] A method for implementing an echo function in a bidirectional forwarding detection mechanism, comprising:

Sending an echo packet to the remote end, where the source address and the destination address in the IP header of the echo packet are the IP addresses of the interface that sends the echo packet;

The echo message is analyzed and processed according to the authentication parameter in the echo message of the remote loopback.

[2] The method according to claim 1, wherein before the sending the echo message, the source address and the destination in the IP header of the echo message are further included in a session establishment or state switching process. The end address is set to the IP address of the interface that sends the echo message.

[3] The method according to claim 1 or 2, further comprising: before sending the echo message:

The local descriptor My Discriminator in the echo message is swapped with the remote descriptor Your Discriminator.

[4] The method according to claim 2, further comprising: before analyzing the echo message:

Receiving a negotiation packet sent by the remote end;

Determining whether the received packet is an echo negotiation packet;

If the packet is an echo negotiation packet, it is determined whether the echo negotiation packet satisfies the filtering rule. If the echo negotiation packet satisfies the filtering rule, the echo packet is analyzed and processed.

[5] The method according to claim 4, wherein the filtering rule is an access control list mechanism.

[6] The method according to claim 3, wherein the receiving the echo message of the remote loopback, analyzing and processing the echo message according to the authentication parameter in the echo message And determining, according to the port number of the remote loop report, whether the packet of the remote loopback is an echo packet; if the remote loopback report is an echo packet, according to the echo packet, The Discriminator identifies parameters and analyzes the echo messages.

[7] The method according to claim 6, wherein the receiving the echo message of the remote loopback, analyzing and processing the echo message according to the authentication parameter in the echo message Also includes:

If the remote ring report message is a normal two-way forwarding detection mechanism message, according to the ordinary two-way forwarding detection mechanism message

The Discriminator identifies parameters and analyzes the echo messages.

[8] The method according to claim 1 or 2, wherein the method further comprises: after receiving the echo message, the remote end triggers an internet protocol message protocol redirection function, and the received echo is received. The message is looped back.

[9] A system for implementing an echo function in a bidirectional forwarding detection mechanism, characterized in that the system comprises a first functional entity and a second functional entity, wherein:

The first function entity is configured to send the echo message to the second function entity, where the source end and the destination end address in the IP header of the echo message are the IP address of the interface that sends the echo message; Receiving an echo message sent by the first function entity, and looping the received echo message back to the first functional entity;

[10] The system of claim 9, wherein the system further comprises:

The third functional entity is configured to receive the packet sent by the network side, and determine whether the received packet satisfies the rule. If the received packet satisfies the rule, the first functional entity is triggered.

[11] The system according to claim 10, wherein the third functional entity is independently set on the network side; or is disposed in the first functional entity.

[12] The system according to claim 9, wherein the second functional entity triggers an internet control message protocol redirection function after receiving the echo message sent by the first functional entity, and the received echo is received. The message loops back to the first functional entity.

[13] The system according to claim 9, wherein the first functional entity is further configured to: use a local descriptor My Discriminator and a remote descriptor in the echo message. Discriminator swap positions.

[14] The system according to any one of claims 9 to 13, wherein the first functional entity is: a router; and the second functional entity is specifically: a router.

[15] A functional entity, wherein the functional entity comprises:

The sending module is configured to set the source and destination addresses in the IP header of the echo packet to the IP address of the interface that sends the echo packet, and send the configured echo message to other functional entities on the network side.

The analysis processing module is configured to receive echo messages of loopbacks of other functional entities on the network side, and analyze and process the packets according to the authentication parameters in the packets.

[16] The functional entity according to claim 15, wherein the setting and sending module specifically includes:

a setting unit, configured to set the source end and the destination end address in the IP header of the echo packet to an IP address of an interface for sending the echo message, and set an authentication parameter of the echo message;

The sending unit is configured to send an echo message that is set by the setting unit to other functional entities on the network side.

[17] The functional entity according to claim 15, wherein the analysis processing module comprises: a receiving unit, configured to receive an echo message of a loopback of other functional entities on the network side.

[18] The functional entity according to claim 15, wherein the functional entity further comprises: a determining triggering module: configured to receive a packet sent by the network side, and determine whether the received packet satisfies a rule; In the case where the message satisfies the rule, the first functional entity is triggered.

[19] A functional entity, comprising: a receiving module, a redirecting module, and a loopback module, wherein:

The receiving module is configured to receive an echo message sent by the network side functional entity, and after receiving the echo message, trigger the redirection module;

The redirection module is configured to: when triggered by the receiving module, start an internet protocol message protocol redirection function, and perform a redirection operation on the echo message received by the receiving module;

The loopback module is configured to loop back the echo packets processed by the redirection module to the network side functional entity.

[20] A functional entity, wherein the functional entity includes a receiving module, and the first determining trigger Module, second judgment trigger module and echo function startup module, wherein:

a receiving module, configured to receive a packet sent by a network side functional entity;

The first determining triggering module is configured to determine whether the packet received by the receiving module is an echo function negotiation packet, and trigger the second determining triggering module after determining that the packet is an echo function negotiation packet; the second determining triggering module And determining, by the first judgment triggering module, whether the echo function negotiation packet determined by the first judgment triggering module satisfies the filtering rule, and triggering the echo function starting module after the echo function negotiation packet satisfies the rule;

The echo function starting module is configured to start the echo function in the bidirectional forwarding detection mechanism under the trigger of the first determining triggering module.

[21] The functional entity according to claim 20, wherein the filtering rule used by the second determining triggering module is an access control list mechanism.

[22] The functional entity according to claim 20, wherein the functional entity is independently set on the network side; or is disposed in other functional entities on the network side.