WO2009026849A1

WO2009026849A1 - Duplicate address detection method and network node device for address conflict

Info

Publication number: WO2009026849A1
Application number: PCT/CN2008/072127
Authority: WO
Inventors: Fengcheng Liu
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-08-30
Filing date: 2008-08-25
Publication date: 2009-03-05
Also published as: CN101110712A; CN100495992C

Abstract

A duplicate address detection method for address conflict is disclosed in the present invention. The method includes: the conflicted node searching a duplicate address list according to the conflict address when an address conflict is detected; checking whether or not the conflict address hits the duplicate address list information according to the searching result while if not, configuring the duplicate address list information according to the conflict address, and otherwise updating the duplicate address list information according to the conflict address; initiating a duplicate address detection to the conflicting node according to the duplicate address list information. Accordingly, a network node device is also disclosed in the present invention. According to the duplicate address detection method and network node device for address conflict of the present invention, the DAD detection can be initiated so as to detect the link variety in time, and the unusable status period of the conflicted node can be reduced as much as possible.

Description

Duplicate address detection method for address conflict and network node device

The present invention relates to the field of network communications, and in particular, to a duplicate address detection method for address conflicts and a network node device. Background technique

In Internet Protocol Version 6 (IPv6), the address space is quite large, so that every grain of sand on the earth can have an IPv6 address, so every device in the user network can have a global search. The address of the address. Address assignment in IPv6 can be divided into two broad categories: stateful address assignment and stateless address assignment based on the Dynamic Host Configuration Protocol (DHCP). The former can strictly control the address allocation, and the stateless address allocation is that the host or the terminal obtains a 64-bit prefix by obtaining a Router Advertisement (RA) message from the router, and then attaches the host interface identifier of the RA message to obtain the host interface identifier. 128-bit IPv6 address.

In order to avoid the fact that two nodes in the broadcast type network have the same IP address, RFC2462 specifies that an IPv6 unicast address must be duplicated in the subnet sharing the same prefix space before being assigned to an interface (Duplicate Address Detection) , DAD ), to ensure that the address is unique within the subnet.

In actual network management, conflicts may occur due to static configuration. As shown in Figure 1, the network has configured link-local address FE80::1 for router A. If you configure router B with the same link-local address FE80::1 at this time, it will be assigned to router B before the address is assigned to router B. Perform DAD detection to ensure the uniqueness of the address in the link. After a DAD probe fails, Router B conflicts with the link-local address, causing the interface configured with the duplicate address on Router B to be in the protocol DOWN state. If at this time, Router A changes its link-local address, such as FE80: :2. At this time, the link-local address FE80::1 configured on Router B is unique and can be used. However, because Router B lacks a reasonable detection mechanism, it cannot detect the change of Router A in the link in time. The local address FE80::1 is still unavailable. In the process of implementing the present invention, the inventors have found that in the prior art, due to the lack of a reasonable detection mechanism by the conflicting node, the changes occurring in the link cannot be detected in time (for example, the node causing the conflict changes the address causing the conflict, or The node causing the conflict is detached from the network, resulting in the conflicted node being in the long-term or always without human intervention. Unavailable status. Summary of the invention

The embodiment of the invention provides a method for detecting a duplicate address of an address conflict and a network node device, which adopts an address-replicating-initiative detection (AD-ID) mechanism to actively initiate a duplicate address detection (DAD detection). To detect link changes in time, so that conflicting nodes are available in a timely manner.

In one aspect, an embodiment of the present invention provides a method for detecting duplicate addresses for address conflicts, including:

After detecting the occurrence of an address conflict, the conflicted node retrieves the duplicate address list according to the conflicting address; according to the search result, it is checked whether the conflicting address hits the duplicate address list, and if there is no hit, the duplicate address list information is configured according to the conflicting address, otherwise, according to The search result updates the duplicate address list information;

Determining duplicate address detection to the node causing the collision according to the repeated address list information.

In another aspect, the embodiment of the present invention further provides a network node device, including multiple communication interface units, connected to other network or network node devices, and receiving data packets from other network node devices, where the network The node device also includes:

a list storage unit, configured to store a duplicate address list;

a retrieval unit, configured to retrieve a duplicate address list in the list storage unit according to the conflict address, and output the retrieval result;

a search result processing unit configured to: when the search result of the search unit is a missed duplicate address list, configure the duplicate address list information in the list storage unit according to the conflict address, or when the search result of the search unit is a hit duplicate address list, according to Retrieving the result of updating the duplicate address list information in the list storage unit;

An active detecting unit is configured to actively initiate duplicate address detection according to the duplicate address list information stored in the list storage unit.

In summary, the method for detecting a duplicate address conflict and the network node device provided by the embodiment of the present invention adopts an Address Duplicate-Initiative Detection (AD-ID) mechanism, that is, introduces a duplicate address list ( Duplicate Address List, DAL ), by the conflicting node, by retrieving the information in the DAL list and actively initiating DAD detection according to the information recorded in the DAL list. The link change is detected, the period of the unavailable state of the conflicting node is reduced as much as possible, and the reliability of the communication system is improved. DRAWINGS

Figure 1 is a schematic diagram of an example of repeated address conflicts;

2 is a schematic structural diagram of a network node device according to an embodiment of the present invention;

3 is a schematic structural diagram of a search result processing unit described in FIG. 2;

4 is a schematic structural diagram of a network node device according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a detection result processing unit illustrated in FIG. 4; FIG.

6 is a flowchart of a first specific embodiment of a method for detecting duplicate addresses of address conflicts provided by the present invention;

Figure Ί is a flow chart of a second specific embodiment of a method for detecting duplicate addresses of address conflicts provided by the present invention. detailed description

The method for detecting duplicate addresses of address conflicts and the network node device provided by the embodiment of the present invention adopts an Address Duplicate-Initiative Detection (AD-ID) mechanism to detect a chain in time by actively initiating DAD detection. The road changes, making the conflict nodes available in a timely manner.

A method for detecting a duplicate address conflict and a technical solution for a network node device according to an embodiment of the present invention are described in detail below with reference to the accompanying drawings.

2 is a schematic structural diagram of a network node device according to an embodiment of the present invention; the network node device may include:

The communication interface unit 1 is connected to other network or network node devices and receives data packets from other network node devices;

The list storage unit 2 is configured to store a Duplicate Address List (DAL), where the DAL list is used to save conflicting address information, and the options include: a conflicting address, a conflicting interface chain, a collision count, and an aging time. Media Access Control (MAC) address of the node causing the conflict (optional);

a retrieval unit 3, configured to retrieve the DAL list in the list storage unit 1 according to the conflict address, And outputting the search result;

The retrieval result processing unit 4, when the retrieval result of the retrieval unit 3 is a missed duplicate address list, configures the duplicate address list information in the list storage unit 2 according to the conflict address, or when the retrieval result of the retrieval unit 3 is a hit duplicate address At the time of list, the duplicate address list information in the list storage unit 2 is updated according to the retrieval result;

The active detecting unit 5 is configured to initiate active DAD detection according to the DAL list information stored in the list storage unit 2, specifically, when the timing reaches the aging time, select an interface in the conflicting interface chain (for example, the earliest occurs) Conflicting interface) Initiates a DAD probe to the node that caused the conflict.

As shown in FIG. 3, the search result processing unit 4 described in FIG. 2 may include:

The determining unit 43 is configured to determine whether the conflicting address hits the duplicate address list, and output a judgment result;

The configuration unit 41, when the determination result output by the determining unit 43 is a miss, is used to add a new record related to the conflicting address in the DAL list according to the conflicting address, such as: a conflicting address, a conflicting interface chain, a collision count, Recording such as aging time;

The list updating unit 42 is configured to update the DAL list option information according to the search result when the determination result of the determining unit 43 is a hit, which may specifically include:

The aging time reset unit 421 is configured to reset the aging time of the aging time when the conflicting interface hits the interface recorded in the conflicting interface chain.

The interface management unit 422, when the conflicting interface is not the interface recorded in the conflicting interface chain, adding the information of the conflicting interface to the conflicting interface chain;

The conflict count management unit 423 adds the count information to the conflict count when the conflict interface is not the interface recorded in the conflicting interface chain.

It should be noted that the data structure description of the DAL list mentioned in the embodiment of the present invention and all the following embodiments is as shown in Table 1, Table 1 Among them, the explanation of each option field is as follows: Conflict Address: Save the conflicting address;

Conflicting interface chain: Save the conflicting interface;

Collision count: This field is used in conjunction with the previous field. When the count is 0, the entry is deleted.

Aging time: The time when the DAD detection is re-initiated;

The MAC address of the node causing the conflict (optional): the MAC address of the node causing the conflict is saved. Referring to FIG. 4, it is a schematic structural diagram of a network node device according to an embodiment of the present invention; 2 The network node device has the same structure, and further includes a detection result processing unit 6 for processing the result detected by the active detection unit. The specific structure of the detection result processing unit 6 is as shown in FIG. 5, which specifically includes:

The address analyzing unit 61 is configured to determine, according to the DAD detection result, whether the conflicting address is unique. The aging time triggering unit 62 is configured to trigger the aging time reset when the address analyzing unit 61 analyzes that the conflicting address is not unique. Unit, reset aging time;

The counting trigger unit 63 is configured to: when the address analyzing unit 61 analyzes that the conflicting address is unique, triggering the conflict count management unit to decrement the count value by one;

The interface triggering unit 64 is configured to: when the address analyzing unit 61 analyzes that the conflicting address is unique, triggering the interface management unit to remove the conflicting interface.

The technical solution of the network node device according to the embodiment of the present invention is described in detail above. The technical solution of the method for detecting the repeated address conflict in the embodiment of the present invention will be described in detail below with reference to FIG. 6 and FIG.

Referring to Figure 6, there is shown a flow chart of a first specific embodiment of a method for detecting duplicate addresses of address conflicts provided by the present invention. The method for detecting duplicate addresses for address conflicts includes:

Step S1, after detecting an address conflict, the conflicted node retrieves the DAL list according to the conflicting address;

Step S2, checking whether the conflict address hits the duplicate address list according to the search result, and if there is no hit, configuring the duplicate address list information according to the conflict address; otherwise, updating the duplicate address list information according to the search result;

Step S3: Proactively initiate a duplicate address (DAD 'J ) to the node causing the conflict according to the repeated address list information.

The data structure of the DAL list is the same as the DAL list described in the foregoing embodiment, such as Table 1, which includes options: conflict address, conflicting interface chain, collision count, aging time, MAC address of the node causing the collision (optional).

In the step S2, the updating the duplicate address list information according to the search result is specifically: checking whether the conflicting interface hits the conflicting interface chain in the duplicate address list, and if it hits, resetting the aging time, otherwise, increasing Counting information of the conflict count, and adding the conflicting interface information to the conflicting interface chain;

In step S3, the DAD detection is actively initiated to the node causing the conflict according to the duplicate address list information:

When the aging time reaches the aging time, select an interface in the conflicting interface chain (for example, the interface that first conflicts) to initiate DAD detection to the node that caused the conflict.

In a specific implementation, after the step S3, the following steps may be further included:

Determining whether the conflicting address is unique according to the DAD detection result, if not, resetting the aging time; otherwise, proceeding to the next step;

The count value of the conflict count is decremented by 1 and the interface is removed from the conflicting interface chain. When the count value of the conflict count is 0, the duplicate address list corresponding to the conflict address is cleared.

It should be noted that, in the above specific embodiment, the step S1 may be replaced by the following steps: after the conflicting node changes the conflicting address, the RA termination text is sent with the conflicting address as the source address; After receiving the RA termination message, the node parses the source address of the packet, and searches for the duplicate address list by using the source address as the conflict address.

When the duplicate address list is retrieved, if the conflicting address hits the duplicate address list, and the interface of the conflicting node that receives the RA terminating message hits the duplicate address list, the interface is used to cause the conflict. The node initiates a DAD probe.

In order to further illustrate the technical solution of the embodiment of the present invention, a second specific embodiment of a method for detecting duplicate addresses of address conflicts will be presented below with reference to FIG.

As shown in FIG. 7, a method for detecting duplicate addresses for address conflicts includes:

Step S101: After detecting the duplicate address conflict by the DAD detection, the conflicting node searches the DAL list according to the conflicting address, and the data structure description of the DAL list is the same as that in the foregoing embodiment. Step S102: Determine, according to the search result, whether the conflict address hits DAL list, if yes, step S103 is performed, otherwise, step S106 is performed;

Step S103, checking whether the conflicting interface hits the conflicting interface in the DAL list. Chain, if yes, proceed to step S104, otherwise, perform step S105;

Step S104, when the conflicting interface hits the DAL list, the aging time of the DAL list is reset to avoid excessive DAD detection, and then step S107 is performed;

Step S105, when the interface that has collided does not hit the DAL list, the conflicting interface information is added in the conflicting interface chain of the DAL list, and the count information of the conflict count is increased, and then step S107 is performed;

Step S106: If the conflicting address does not hit the DAL list, add the DAL list information corresponding to the conflicting address in the DAL list, that is,

The conflict address is added to the conflicting address option of the DAL list, and the interface information corresponding to the conflicting address is added to the conflicting interface chain option, and the count value of the conflict count is incremented by 1 and the aging time is reset.

Step S107, determining whether the entry of the DAL list starts to age, that is, whether the timing reaches the chrono threshold set in the aging time of the DAL list, and if yes, executing step S108; otherwise, continuing the step;

Step S108: Selecting an interface that is the earliest conflict from the conflicting interface chain of the DAL list to initiate DAD detection;

Step S109, checking whether the conflicting address is unique according to the DAD detection result, if yes, executing step S110, otherwise continuing the step;

Step S110, if it is confirmed that the conflicting address is unique, the interface corresponding to the conflicting address is removed from the conflicting interface chain in the DAL list (the earliest conflicting interface described in step S108), and the conflict is caused. Count the count value minus 1;

Step S111, determining whether the count value of the conflict count is 0, and if yes, executing step S112, otherwise, continuing the step;

Step S112, deleting the DAL list option corresponding to the conflicting address.

It is detected by the above steps that the conflicting address is already unique, that is, restored to a usable state, and the network node can use the address to initiate network communication.

It can be seen from the foregoing embodiment that the method for detecting a duplicate address of an address conflict and the network node device provided by the embodiment of the present invention adopts an Address Duplicate-Initiative Detection (AD-ID) mechanism, that is, introduces a repetition. The Duplicate Address List (DAL) is retrieved by the conflicting node by the information in the DAL list and is actively sent according to the information recorded in the DAL list. DAD detection is used to detect link changes in time, so that conflict addresses are available in a timely manner, and the period of unavailable states of conflicting nodes is reduced as much as possible, thereby improving system reliability and availability.

The above is a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. These improvements and retouchings are also considered. It is the scope of protection of the present invention.

Claims

Rights request

A method for detecting duplicate addresses for address conflicts, comprising:

After detecting an address conflict, the conflicting node retrieves the duplicate address list according to the conflicting address; determines whether the conflicting address hits the duplicate address list according to the search result, and if there is no hit, configures the duplicate address list information according to the conflicting address, otherwise, according to the conflicting address, The search result updates the duplicate address list information;

The method according to claim 1, wherein the options of the duplicate address list comprise: a conflicting address, a conflicting interface chain, a collision count, and an aging time.

3. The method of claim 2, wherein the option of the duplicate address list further comprises: a MAC address of the node causing the collision.

4. The method according to claim 2, wherein the updating the duplicate address list information according to the search result is specifically:

Check whether the conflicting interface hits the conflicting interface chain in the duplicate address list. If it hits, reset the aging time. Otherwise, increase the count information of the collision count, and add the conflicting interface to the conflicting interface chain. Interface information.

The method according to claim 2 or 4, wherein the repeatedly generating the duplicate address detection to the node causing the conflict according to the repeated address list information is specifically:

When the timing reaches the aging time, an interface in the conflicting interface chain is selected to initiate duplicate address detection to the node causing the collision.

The method according to claim 5, wherein the method further comprises: determining whether the conflicting address is unique according to the result of the repeated address detection, and if not, resetting the aging time, otherwise

The count value of the conflict count is decremented by 1, and the interface is removed from the conflicting interface chain, when the conflict is counted When the count value of the number is 0, the duplicate address list information corresponding to the conflict address is cleared.

7. The method according to claim 1 or 2, wherein, after detecting the duplicate address conflict, the conflicting node searches for the duplicate address list according to the conflicting address may be replaced by:

After the conflicting node changes the conflicting address, the route advertisement is terminated by using the conflicting address as the source address.

After receiving the route advertisement termination message, the conflicting node in the same link parses the source address of the packet, and searches for the duplicate address list by using the source address as the conflict address.

8. The method according to claim 7, wherein when the duplicate address list is retrieved, if the conflicting address hits the duplicate address list, and the interface of the conflicting node for receiving the route advertisement termination message is also When a duplicate address list is hit, a duplicate address detection is initiated to the node that caused the conflict.

The method according to claim 8, wherein the method further comprises: determining whether the conflicting address is unique according to the result of the repeated address detection, and if not, resetting the aging time, otherwise

A network node device, comprising: a communication interface unit, connected to another network or network node device, and receiving data packets from other network node devices, wherein the network node device further comprises:

a list storage unit, configured to store a duplicate address list;

a retrieval unit, configured to retrieve a duplicate address list in the list storage unit according to the conflict address, and output a retrieval result;

a retrieval result processing unit, configured to configure the duplicate address list information in the list storage unit according to the conflicting address when the retrieval result of the retrieval unit is a missed duplicate address list, or when the retrieval result of the retrieval unit is a hit duplicate address When listing, updating the duplicate address list information in the list storage unit according to the retrieval result; The active detecting unit is configured to actively initiate duplicate address detection according to the duplicate address list information stored in the list storage unit.

The network node device according to claim 10, wherein the options of the duplicate address list include: a conflicting address, a conflicting interface chain, a collision count, and an aging time.

The network node device according to claim 10 or 11, wherein the search result processing unit comprises:

a determining unit, configured to determine whether the conflicting address hits a duplicate address list, and output a judgment result;

a configuration unit, configured to add a new record related to the conflict address in the duplicate address list according to the conflicting address when the judgment result output by the determining unit is a miss;

The list updating unit is configured to update the duplicate address list option information according to the retrieval result when the determination result of the determining unit is a hit.

The network node device according to claim 12, wherein the list updating unit comprises:

The aging time reset unit is used to reset the aging time of the aging time when the conflicting interface hits the interface recorded in the conflicting interface chain.

An interface management unit, when the conflicting interface is not the interface recorded in the conflicting interface chain, adding the information of the conflicting interface to the conflicting interface chain;

The conflict count management unit increases the count information in the conflict count when the conflict interface is not the interface recorded in the conflicting interface chain.

The network node device according to claim 13, wherein the network node device further includes a detection result processing unit, and the detection result processing unit specifically includes:

An address analyzing unit, configured to determine, according to a result of the duplicate address detection, whether the conflicting address is unique;

An aging time triggering unit, configured to: when the address analysis unit analyzes that the conflicting address is not unique, trigger an aging time resetting unit to reset the aging time; a counting triggering unit, configured to trigger the conflict counting management unit to decrement the count value of the corresponding conflict count by 1 when the address analyzing unit analyzes that the conflicting address is unique;

And an interface triggering unit, configured to: when the address analyzing unit analyzes that the conflicting address is unique, triggering the interface management unit to remove the conflicting interface from the conflicting interface chain.