A method and system for incremental data transmission in DNS zones

Abstract

This application discloses a method and system for incremental data transmission in DNS zones. First, a new incremental transmission request protocol is established between the primary and secondary zone servers to enable incremental synchronization detection and incremental zone configuration return from the primary server. When the secondary zone server initiates an update request according to its local update timeout mechanism or periodic update mechanism, it follows the newly established request protocol. Then, when the primary zone server reads that the protocol type is the target protocol type, it checks whether the current primary zone server supports incremental transmission and simultaneously reads the address list of other primary zone servers. It then sequentially sends query requests to other primary zone servers to check whether they support incremental configuration synchronization, obtaining a list of primary zone servers that support incremental configuration synchronization. Finally, it returns the query results to the secondary zone server. This invention ensures that even in scenarios with multiple primary servers with different configurations, incremental synchronization can be used to complete configuration synchronization normally.

Description

Technical Field

[0001] This invention relates to the field of computer technology, and in particular to a method and system for incremental data transmission in the DNS zone. Background Technology

[0002] DNS servers can be configured in a primary-secondary mode, where the secondary DNS server synchronizes its configuration with the primary DNS server to ensure consistent configuration between the primary and secondary servers. To reduce the amount of data transferred between zones, DNS provides the IXFR command to control the server to transmit incremental configurations to the client.

[0003] Each DNS zone update provides an incrementing sequence number, indicating the current zone's configuration. When a DNS client requests incremental zone data transfer, it transmits the sequence number of the locally existing zone data to the server. If the server has data between the requested sequence number and the latest sequence number, it transmits the zone data between the latest sequence number and the client's existing sequence number. If the server does not have the zone data with the sequence number provided by the client, it transmits the full amount of data to the client.

[0004] DNS can provide multiple DNS zone servers, each capable of updating the same zone file. However, the implementation mechanisms of the DNS software on each zone server may differ. Some zone servers may not provide incremental zone transfers, and variations in their cleanup mechanisms can lead to inconsistent sequence numbers for the same zone. Furthermore, human intervention can increase zone sequence numbers, ultimately resulting in the server lacking the sequence number requested by the client, thus preventing incremental updates. For example, suppose DNS zone servers NS1 and NS2 are updating the same zone. NS1 might have sequence numbers 1, 2, and 3, while NS2 might have sequence numbers 1, 3. If a client carries its local zone sequence number 2 and uses the IXFR command to transfer the zone to NS1, an incremental transfer will occur. However, transferring the zone to NS2 will only result in a full transfer because NS2 does not have a sequence number of 2.

[0005] When multiple DNS zone servers exist, if a DNS client uses the IXFR command to synchronize a zone with one of the zone servers, and the server supports incremental zone transfer, it will perform incremental transfer if it matches the sequence number provided by the client; otherwise, it will perform full transfer. It will not check whether other zone servers have zone records with the same sequence number. In this scenario, the amount of data transferred is large, which can lead to performance degradation and high bandwidth consumption. Summary of the Invention

[0006] Based on this, the embodiments of this application provide a method and system for incremental transmission of DNS zone data, which can ensure that configuration synchronization can be completed normally using incremental synchronization in scenarios with multiple master servers with different configurations.

[0007] Firstly, a method for incremental data transmission in the DNS zone is provided, applied to a primary zone server. This method includes:

[0008] Establish an incremental transfer request protocol with the secondary server;

[0009] Receive incremental transmission requests sent by the secondary zone server, and extract the protocol type from the incremental transmission requests; wherein, the incremental transmission requests are generated based on the incremental transmission request protocol;

[0010] When the protocol type is read as the target protocol type, it checks whether the current main zone server supports incremental transmission and reads the address list of other main zone servers.

[0011] Query requests are sent to other primary zone servers in turn to check whether other primary zone servers support incremental configuration synchronization, and a list of primary zone servers that support incremental configuration synchronization is obtained.

[0012] Return the query results to the auxiliary server.

[0013] Optionally, the protocol type can be the newly added OIXFR and NOIXFR types in QTYPE, and a list of other master server addresses can be carried in the Additional field; wherein, the OIXFR type is used to indicate that the current master zone server can provide incremental configuration synchronization, and the NOIXFR type is used to indicate that the current master zone server cannot provide incremental configuration synchronization.

[0014] Optionally, the query results are returned to the secondary zone server, including:

[0015] If other servers support incremental configuration synchronization, return a list of servers that support incremental configuration synchronization; otherwise, check if the current primary zone server address exists in the Additional field of the query package.

[0016] Optionally, the query packet may be checked for the existence of the current primary zone server address in the Additional field, including:

[0017] If it exists, return the full configuration package; otherwise, return a NOIXFR error.

[0018] Optionally, the method further includes:

[0019] If the primary zone server does not support incremental transfer, but the Additional field in the incremental transfer request contains the address of the primary zone server, then the full configuration package is returned to the primary zone server containing the address.

[0020] Optionally, the method further includes:

[0021] If the primary zone server does not support incremental transfer, and the Additional field in the incremental transfer request does not contain the primary zone server address, then the primary zone server cannot provide configuration synchronization.

[0022] Secondly, a method for incremental data transmission in DNS zones is provided, applied to secondary zone servers. This method includes:

[0023] Establish an incremental transfer request protocol with the primary zone server;

[0024] An incremental transfer request is generated based on the incremental transfer request protocol and sent to the main zone server so that the main zone server can extract the protocol type from the incremental transfer request.

[0025] Obtain the query results returned by the primary zone server; wherein, the query results include, when the primary server reads that the protocol type is the target protocol type, checking whether the current primary zone server supports incremental transmission, and simultaneously reading the address list of other primary zone servers, sequentially initiating query requests to other primary zone servers to query whether other primary zone servers support incremental configuration synchronization, and obtaining a list of primary zone servers that support incremental configuration synchronization.

[0026] Optionally, the method further includes:

[0027] Once the list of primary zone servers that support incremental configuration synchronization is obtained, an IXFR request can be sent to the servers that support incremental configuration synchronization to synchronize the configuration.

[0028] Optionally, the query results may also include:

[0029] The primary server has returned the incremental synchronization configuration for the secondary server.

[0030] The main zone server has returned to full zone configuration;

[0031] There are no servers in the main zone that support incremental configuration.

[0032] Thirdly, a DNS zone data incremental transmission system is provided, which includes a secondary zone server and at least one primary zone server, wherein:

[0033] The primary zone server is used to establish an incremental transmission request protocol with the secondary zone server; receive incremental transmission requests sent by the secondary zone server, and extract the protocol type from the incremental transmission requests; wherein, the incremental transmission request is generated based on the incremental transmission request protocol; when the protocol type is read as the target protocol type, it checks whether the current primary zone server supports incremental transmission, and simultaneously reads the address list of other primary zone servers; it sequentially sends query requests to other primary zone servers to query whether other primary zone servers support incremental configuration synchronization, obtains a list of primary zone servers that support incremental configuration synchronization; and returns the query results to the secondary zone server.

[0034] The secondary zone server is used to establish an incremental transmission request protocol with the primary zone server; generate incremental transmission requests based on the incremental transmission request protocol, and send incremental transmission requests to the primary zone server so that the primary zone server can extract the protocol type from the incremental transmission requests; obtain the query results returned by the primary zone server; wherein, the query results include, when the primary server reads that the protocol type is the target protocol type, detecting whether the current primary zone server supports incremental transmission, and simultaneously reading the address list of other primary zone servers, sequentially initiating query requests to other primary zone servers to query whether other primary zone servers support incremental configuration synchronization, and obtaining a list of primary zone servers that support incremental configuration synchronization.

[0035] In the technical solution provided in this application embodiment, a new incremental transmission request protocol is established between the primary and secondary zone servers. This protocol enables incremental synchronization detection and incremental zone configuration return from the primary server. When the secondary zone server initiates an update request using its local update timeout mechanism or periodic update mechanism, it initiates the request according to the newly established protocol. When the primary zone server reads that the protocol type is the target protocol type, it checks whether the current primary zone server supports incremental transmission and simultaneously reads the address list of other primary zone servers. It then sequentially sends query requests to other primary zone servers to check whether they support incremental configuration synchronization, obtaining a list of primary zone servers that support incremental configuration synchronization. Finally, it returns the query results to the secondary zone server. It can be seen that the beneficial effects of this invention are:

[0036] (1) It supports completing configuration synchronization and querying other incremental server addresses with the same request, reducing the number of requests initiated by the client and improving query performance.

[0037] (2) Supports sending requests to detect whether the target server has the capability to support incremental synchronization configuration, satisfying the client's iterative detection of whether the server supports incremental synchronization.

[0038] (3) It can effectively solve the problem of large-scale fluctuations in network traffic caused by configuration differences and reduce traffic costs. Attached Figure Description

[0039] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0040] Figure 1 A flowchart of a DNS zone data incremental transmission method provided in this application embodiment;

[0041] Figure 2 This is a schematic diagram of the iterative query of the auxiliary area server provided in an embodiment of this application;

[0042] Figure 3 This is a schematic diagram of the iterative query of the main area server provided in an embodiment of this application. Detailed Implementation

[0043] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0045] In the description of this invention, the terms “comprising,” “having,” and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are expressly listed, but may also include other steps or units that are not expressly listed but are inherent to these processes, methods, products, or apparatuses, or steps or units added based on further optimizations of the inventive concept.

[0046] The solution of this invention optimizes and modifies the DNS primary and secondary zone synchronization mechanism, ensuring that configuration synchronization can be completed normally using incremental synchronization even in scenarios with multiple primary servers with different configurations. For ease of description below, some terms used in the following text are defined as follows:

[0047] Primary DNS zone server: This refers to the server that provides zone synchronization. In this application, the term "server" or "primary zone server" refers to this server.

[0048] Secondary DNS zone server: This refers to the client that initiates zone synchronization. This server synchronizes its configuration from the primary DNS zone server, ensuring that the configuration of the secondary DNS zone server is consistent with that of the primary DNS zone server. In this application, the client that initiates zone synchronization refers to the secondary DNS zone server.

[0049] IXFR: is the default protocol mechanism provided for DNS zone transport.

[0050] For details, please refer to Figure 1 The document illustrates a flowchart of a DNS zone data incremental transmission method provided in an embodiment of this application. Specifically, when this method is applied to a primary zone server (server-side), it includes the following steps:

[0051] S1 establishes an incremental transfer request protocol with the secondary server (client).

[0052] In this embodiment, a new negotiation mechanism is added between the primary and secondary zone servers to realize incremental synchronization detection of the primary server and incremental zone configuration return.

[0053] In the primary and secondary area communication protocol, a new protocol type and an additional field are added to carry primary server information. For example, QTYPE can add a new protocol type, OIXFR, and this protocol can carry a list of other primary server addresses in the additional field. Below is an example of such a protocol:

[0054]

[0055] Add a new error type indicating that the server cannot provide incremental configuration synchronization. For example: NOIXFR.

[0056] As can be seen, the protocol type in this application can be either the newly added OIXFR type or NOIXFR type in QTYPE, and can also carry a list of other master server addresses in the Additional field; among them, the OIXFR type is used to indicate that the current master zone server can provide incremental configuration synchronization, and the NOIXFR type is used to indicate that the current master zone server cannot provide incremental configuration synchronization.

[0057] S2 receives incremental transmission requests sent by the secondary zone server and extracts the protocol type from the incremental transmission requests.

[0058] Incremental transfer requests are generated based on the incremental transfer request protocol.

[0059] In this embodiment, when the client initiates an update request using the local update timeout mechanism or periodic update mechanism, the request is initiated according to the new negotiation method. The QTYPE field is filled with the new negotiation mechanism OIXFR, and the Additional field is filled according to the client's requirements.

[0060] a) If only checking whether the server supports incremental synchronization of zone configuration, then fill in QTYPE as OIXFR; otherwise, leave it blank.

[0061] b) If incremental configuration is required on the server side, then provide incremental configuration; otherwise, check whether other servers support incremental configuration and return a list of server addresses that support incremental synchronization. In this case, fill in QTYPE as OIXFR, and additionally fill in the addresses of other master servers besides the master server address that directly receives the request.

[0062] c) If the server is required to return the configuration or the address of another server that supports incremental configuration, then in addition to b), the address of the server that directly receives the request should also be added to Additional.

[0063] S3, when the protocol type is the target protocol type, check whether the current main zone server supports incremental transmission, and at the same time read the address list of other main zone servers.

[0064] S4, sequentially sends query requests to other primary zone servers to check whether other primary zone servers support incremental configuration synchronization, and obtains a list of primary zone servers that support incremental configuration synchronization.

[0065] In this embodiment of the application, when the server receives a request from the client, it reads that the value of QTYPE is OIXFR; the specific operations are as follows:

[0066] a) The detection module is invoked to check whether the local server supports incremental transfer, and the Additional resolution module is invoked to read the server address list.

[0067] If incremental configuration synchronization is supported and the server address list includes the local machine address, then the incremental transfer content will be returned directly. For example: (Note: QTYPE is marked with IXFR, indicating an incremental transfer response.)

[0068]

[0069] ii. If incremental area transfer is not supported, proceed to step b);

[0070] b) Call the module that parses the Additional field to read the list of other servers.

[0071] If the address in the other server list is only the local server address, then the full zone synchronization configuration will be returned. The returned content will have the same format as the content returned in i) below a), except that QTYPE is set to AXFR.

[0072] If all addresses in the other server list are other server addresses, proceed to step c).

[0073] c) Send query requests to other servers sequentially to check if they support incremental configuration synchronization, and obtain a list of servers that support incremental configuration synchronization.

[0074] i. The requested content is the same as the example in step S1, with the QTYPE type being OIXFR, and the Additional field being empty.

[0075] ii. If other servers support incremental transfers, the returned QTYPE type is OIXFR, and the error type is NR (indicating no error exists). Below is an example of the returned value:

[0076]

[0077] iii. If other servers do not support incremental transfers, the returned QTYPE type is OIXFR, and the error type is NOIXFR. The example of the returned data packet is the same as the example in ii) of step c), except that RCODE is set to NOIXFR.

[0078] d) Return the results to the client. If other servers support incremental configuration synchronization, return a list of servers that support incremental configuration synchronization; otherwise, check if the local server address exists in the Additional field of the query package. If it exists, return the full configuration package; otherwise, return a NOIXFR error.

[0079] i. After step c), once other master servers that support incremental transfer are found, a list of addresses of supporting servers is returned to the client. The specific format is as follows: (RCODE is set to NR, and Additional is set to the list of server addresses that support incremental transfer).

[0080]

[0081] ii. If none of the servers support incremental transfer, but the Additional field of the request packet contains the local server address, then a full configuration packet is returned. See 3-b)-i) for the packet format description.

[0082] iii. If none of the servers support incremental transfer, and Additional does not contain the local server address, then return with RCODE set to NOIXFR and Additional field left empty.

[0083] S5 returns the query results to the secondary server.

[0084] After receiving the response from the server, the client performs different processing based on the values ​​of RCODE, Additional, and QTYPE, specifically:

[0085] a) RCODE is NOERROR and QTYPE is IXFR, indicating that the server has returned the incremental synchronization configuration.

[0086] b) RCODE is NOERROR and QTYPE is AXFR, indicating that the server has returned the full configuration.

[0087] c) If RCODE is NOERROR and QTYPE is OIXFR, the server returns a list of servers that support incremental configuration.

[0088] d) RCODE is NOIXFR, indicating that the server does not support incremental configuration.

[0089] If the client receives an incremental list of servers from the server, it can send an IXFR request to a server that supports incremental configuration synchronization to synchronize the configuration.

[0090] When this method, which is based on the above-mentioned incremental data transmission method for DNS zones, is also applied to primary zone servers, it specifically includes the following steps:

[0091] Establish an incremental transfer request protocol with the primary zone server;

[0092] An incremental transfer request is generated based on the incremental transfer request protocol and sent to the main zone server so that the main zone server can extract the protocol type from the incremental transfer request.

[0093] Retrieve the query results returned by the primary zone server; the query results include: when the primary server reads that the protocol type is the target protocol type, it checks whether the current primary zone server supports incremental transmission, and at the same time reads the address list of other primary zone servers, and sequentially sends query requests to other primary zone servers to query whether other primary zone servers support incremental configuration synchronization, thus obtaining a list of primary zone servers that support incremental configuration synchronization.

[0094] In an optional embodiment of this application, the method further includes, after obtaining a list of primary zone servers that support incremental configuration synchronization, initiating an IXFR request to the servers that support incremental configuration synchronization to perform configuration synchronization.

[0095] In optional embodiments of this application, the query results may also include: the primary zone server has returned incremental synchronization configuration; the primary zone server has returned full configuration; and the primary zone server does not have a server that supports incremental configuration.

[0096] This application also provides a DNS zone data incremental transmission system. It includes a secondary zone server and at least one primary zone server, wherein:

[0097] The primary zone server is used to establish an incremental transfer request protocol with the secondary zone server; it receives incremental transfer requests sent by the secondary zone server and extracts the protocol type from the incremental transfer request; the incremental transfer request is generated based on the incremental transfer request protocol; when the protocol type read is the target protocol type, it checks whether the current primary zone server supports incremental transfer, and simultaneously reads the address list of other primary zone servers; it sequentially sends query requests to other primary zone servers to query whether other primary zone servers support incremental configuration synchronization, obtaining a list of primary zone servers that support incremental configuration synchronization; and returns the query results to the secondary zone server.

[0098] The secondary zone server is used to establish an incremental transfer request protocol with the primary zone server; it generates incremental transfer requests based on the incremental transfer request protocol and sends them to the primary zone server so that the primary zone server can extract the protocol type from the incremental transfer requests; it obtains the query results returned by the primary zone server; the query results include, when the primary server reads that the protocol type is the target protocol type, it checks whether the current primary zone server supports incremental transfer, and simultaneously reads the address list of other primary zone servers, and sequentially sends query requests to other primary zone servers to query whether other primary zone servers support incremental configuration synchronization, thus obtaining a list of primary zone servers that support incremental configuration synchronization.

[0099] In summary, it can be seen that the present invention achieves:

[0100] (1) Add a new protocol type to the communication protocol between the primary and secondary servers.

[0101] (2) The main zone server has the ability to identify new protocols and parse the server list with additional fields.

[0102] (3) The main server needs to add the ability to determine whether incremental synchronization is supported.

[0103] (4) The primary server must have the ability to initiate queries between primary server clusters.

[0104] (5) The auxiliary server must have the ability to initiate new protocols.

[0105] (6) The secondary zone server should have the ability to send multiple zone configuration synchronization requests to different primary zone servers.

[0106] The DNS zone data incremental transmission system provided in this application embodiment is used to implement the above-described DNS zone data incremental transmission method. Specific limitations of the DNS zone data incremental transmission system can be found in the above-described limitations of the DNS zone data incremental transmission method, and will not be repeated here. Each part of the above-described DNS zone data incremental transmission system can be implemented entirely or partially through software, hardware, or a combination thereof. Each of the above modules can be embedded in or independent of the processor in the device in hardware form, or stored in the memory of the device in software form, so that the processor can call and execute the operations corresponding to each of the above modules.

[0107] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A DNS zone data incremental transfer method, characterized in that, The method applied to a primary zone server comprises: establishing an incremental transmission request protocol with a secondary zone server; receiving an incremental transmission request sent by the secondary zone server, and extracting a protocol type from the incremental transmission request, wherein the incremental transmission request is generated based on the incremental transmission request protocol; when the protocol type is read as a target protocol type, detecting whether the current primary zone server supports incremental transmission, and reading a list of addresses of other primary zone servers; sequentially initiating a query request to the other primary zone servers to query whether the other primary zone servers support incremental configuration synchronization, and obtaining a list of primary zone servers supporting incremental configuration synchronization; returning a query result to the secondary zone server; the protocol type is an OIXFR type and a NOIXFR type newly added in QTYPE, and a list of addresses of other primary servers is carried in an additional field Additional; the OIXFR type is used to represent that the current primary zone server provides incremental configuration synchronization, and the NOIXFR type is used to represent that the current primary zone server cannot provide incremental configuration synchronization; returning the query result to the secondary zone server, comprising: when the other servers support incremental configuration synchronization, returning a list of servers supporting incremental configuration synchronization; otherwise, according to whether the Additional field of the query packet contains the address of the current primary zone server, returning a full configuration packet or a NOIXFR error. the method further comprises:

2. The DNS zone data incremental transfer method of claim 1, wherein, when the primary zone server does not support incremental transmission, but the Additional field of the incremental transmission request contains the address of the primary zone server, returning a full configuration packet to the primary zone server containing the address. the method further comprises:

3. The DNS zone data incremental transfer method of claim 2, wherein, when the primary zone server does not support incremental transmission, and the Additional field of the incremental transmission request does not contain the address of the primary zone server, returning that the primary zone server cannot provide configuration synchronization. The method applied to a secondary zone server comprises:

4. A DNS zone data incremental transfer method, characterized by, establishing an incremental transmission request protocol with a primary zone server; generating an incremental transmission request based on the incremental transmission request protocol, and sending the incremental transmission request to the primary zone server, so that the primary zone server extracts a protocol type from the incremental transmission request; obtaining a query result returned by the primary zone server; wherein the query result comprises: when the primary server reads the protocol type as a target protocol type, detecting whether the current primary zone server supports incremental transmission, and reading a list of addresses of other primary zone servers, sequentially initiating a query request to the other primary zone servers to query whether the other primary zone servers support incremental configuration synchronization, and obtaining a list of primary zone servers supporting incremental configuration synchronization; ​ The protocol type is an OIXFR type and a NOIXFR type added in the QTYPE, and other master server address lists are carried in an additional field Additional; the OIXFR type is used to represent that the current master zone server provides incremental configuration synchronization, and the NOIXFR type is used to represent that the current master zone server cannot provide incremental configuration synchronization; The master zone server returns a query result to the secondary zone server, including: when other servers support incremental configuration synchronization, a server list supporting incremental configuration synchronization is returned; otherwise, whether the current master zone server address exists in the Additional field of the query packet is determined; Whether the current master zone server address exists in the Additional field of the query packet, including: if the current master zone server address exists, a full configuration packet is returned, otherwise, a NOIXFR error is returned.

5. The DNS zone data incremental transfer method of claim 4, wherein, The method further includes: When the master zone server list supporting incremental configuration synchronization is obtained, an IXFR request is initiated to the server supporting incremental configuration synchronization for synchronization configuration.

6. The DNS zone data incremental transfer method of claim 4, wherein, The query result further includes: The master zone server has returned zone incremental synchronization configuration; The master zone server has returned zone full configuration; The master zone server does not support incremental configuration.

7. A DNS zone data incremental transfer system, characterized by, The method includes a secondary zone server and at least one master zone server, wherein: The master zone server is configured to establish an incremental transmission request protocol with the secondary zone server, receive an incremental transmission request sent by the secondary zone server, extract a protocol type from the incremental transmission request, wherein the incremental transmission request is generated based on the incremental transmission request protocol, when the protocol type is read as a target protocol type, it is detected whether the current master zone server supports incremental transmission, and a list of other master zone server addresses is read, a query request is initiated to the other master zone servers in turn, it is queried whether the other master zone servers support incremental configuration synchronization, a master zone server list supporting incremental configuration synchronization is obtained, and a query result is returned to the secondary zone server; The secondary zone server is configured to establish an incremental transmission request protocol with the master zone server, generate an incremental transmission request based on the incremental transmission request protocol, and send the incremental transmission request to the master zone server, so that the master zone server extracts a protocol type from the incremental transmission request, and obtains a query result returned by the master zone server; wherein the query result includes that when the master server reads the protocol type as a target protocol type, it is detected whether the current master zone server supports incremental transmission, a list of other master zone server addresses is read, a query request is initiated to the other master zone servers in turn, it is queried whether the other master zone servers support incremental configuration synchronization, a master zone server list supporting incremental configuration synchronization is obtained, and a query result is returned to the secondary zone server; The protocol type is an OIXFR type and a NOIXFR type added in the QTYPE, and other master server address lists are carried in an additional field Additional; the OIXFR type is used to represent that the current master zone server provides incremental configuration synchronization, and the NOIXFR type is used to represent that the current master zone server cannot provide incremental configuration synchronization; The primary zone server returns the query result to the secondary zone server, including: when other servers support incremental configuration synchronization, the list of servers supporting incremental configuration synchronization is returned; otherwise, whether the current primary zone server address exists in the Additional field of the query package is determined; According to whether the current primary zone server address exists in the Additional field of the query package, including: if the current primary zone server address exists, a full configuration package is returned, otherwise, a NOIXFR error is returned.

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