KR20040066331A - Domain name service processing system and method on intra network - Google Patents

Abstract

PURPOSE: A system and a method for processing a DNS(Domain Name Server) message on the intranet are provided to perform an IPv4/IPv6(Internet Protocol version) query and response for a mutual DNS call on a single network coexisting an IPv4 node and an IPv6 node. CONSTITUTION: An NAT(Network Address Translation)(210) generates/transmits the query of an IPv4/IPv6 type for the query of a source node(230) and confirms the response of a destination node for the query. If the type of the response is identical with the source query, the NAT transmits the response to the source node. If not, the response is converted into the same type as the query of the source node and is transmitted to the source node. A DNS server(220) transmits the source query of the IPv4/IPv6 type on the NAT to the destination node and transmits the response of the destination node to the NAT. The NAT comprises the DNS-ALG(Application Level Gateway) NAT performing an agent function of the source node.

Description

System and method for processing DSN messages in an intra network {DOMAIN NAME SERVICE PROCESSING SYSTEM AND METHOD ON INTRA NETWORK}

The present invention relates to an intra network, and more particularly, to a system and method for processing a DNS message in an intra network in which an IPv4 node and an IPv6 node coexist.

As the current IPv4 network develops, the limitations of the IPv4 network have emerged.

IPv6 includes a number of additional features compared to IPv4, including infinite addresses and portability. IPv6 is becoming active based on research institutes considering next-generation networks.

Even though IPv6 has good performance and function, it is currently divided into existing structure of IPv4 network and dualized and used independently, and the applications used in each network are also being developed.

Therefore, there is a need to interwork existing IPv4 and IPv6 networks, and for this purpose, a network address translation (NAT) has been proposed to connect two networks having different address systems. NAT is an IETF standard that enables interworking by translating IP packets between networks with different addressing systems.

In an IP based network, the IP address becomes the ID of the network nodes.

Therefore, programs often communicate using IDs, and when NAT is changed to another address system, applications must make appropriate changes. This role is played by an application level gateway (ALG).

ALG can be different for each application and is necessary for interworking with IPv6.

However, the DNS message used to access a domain name has a different form between IPv4 and IPv6, and therefore requires an ALG function for proper conversion. This is called DNS-ALG.

1 is a block diagram of an intra network in which an IPv4 node and an IPv6 node coexist.

In FIG. 1, if an IPv6 terminal simply calls an IPv4 node and the IPv4 nodes call IPv6 nodes, the IPv6 terminal may perform transmission and reception using an IPv6 / IPv4 NAT.

In addition, in Fig. 1, the DNS message can be solved simply by changing the DNS query for IPv6 to an IPv4 DNS query and the DNS query for IPv4 to a DNS query for IPv6.

However, there are no problems in the prior art if two completely independent dual networks are present, but if they exist in the same network in combination, it is not possible to simply change the IP of the DNS message.

That is, in general, when an IPv4 node and an IPv6 node coexist, the DNS name alone does not know whether to call an IPv4 node or an IPv6 node.

For example, when an IPv4 node sends a DNS message in a single network, that is, when an IPv4 node application calls a DNS message node.co.kr, the following occurs.

First, if node.co.kr is an IPv4 node, NAT function is not needed.

Second, if node.co.kr is an IPv6 node, DNS message should be changed to IPv6 address and A6 or AAAA format.

Third, if node.co.kr is an IPv4 / IPv6 dual node, the response varies depending on which protocol the application supports.

Therefore, conventionally, in a network in which an IPv4 node and an IPv6 node coexist, a simple change of IP is impossible and there is a problem in which format the DNS message should be transmitted.

Accordingly, the present invention provides a DNS in an intra network in which an IPv4 node and an IPv6 node coexist in order to improve a conventional problem, and to perform IPv4 and IPv6 queries and responses for DNS calls. It is an object of the present invention to provide a message processing system and method.

That is, the present invention generates an IPv4 and IPv6 query for a query to receive the response and receives the response so that the IPv4 network and the IPv6 network node coexist with the destination node by using the domain name in the coexistence network. The purpose is to.

1 is a configuration diagram of a single network in which typical IPv4 and IPv6 nodes exist.

2 is a block diagram of a system for processing a DNS message in an embodiment of the present invention;

Figure 2a is a signal flow diagram illustrating a DNS query and response process of an IPv4 node in an embodiment of the present invention.

Figure 2b is a signal flow diagram illustrating a DNS query and response process of an IPv6 node in an embodiment of the present invention.

3 is a flowchart illustrating an operation of processing a DNS query in an embodiment of the present invention.

4 to 6 are flowcharts illustrating operations of DNS response processing according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

210: network address translator 220: DNS server

230: IPv4 node 240: IPv6 node

In order to achieve the above object, the present invention generates and transmits an IPv4 and IPv6 type query to a query of a node, in an intra network in which an IPv4 node and an IPv6 node coexist, and responds to the query. If it is the same type as the query of the node and transmits to the node as it is, and if it is not the same type as the query of the node, the network address translator (NAT) to convert to the same type as the query of the node and transmit it to the node, And a DNS server that transmits IPv4 and IPv6 type queries to the destination node and sends a response from the destination node to the network address translator.

The network address translator is a DNS-ALG NAT, and it is configured to perform an agent function of the node to be connected to the destination node because the node to be connected is unknown whether the destination node is an IPv4 node or an IPv6 node.

In addition, in order to achieve the above object, the present invention provides a method for generating IPv4 and IPv6 queries for IPv4 or IPv6 queries in a different network, especially an intra network in which IPv4 nodes and IPv6 nodes coexist, and transmitting them to a target node. And, if the response of the target node is the same type as the source query, and responds as it is, if the other response is characterized in that the step of converting and responding to the same type as the source query.

Hereinafter, the present invention will be described in detail with reference to the drawings.

In the intra network for the embodiment of the present invention, as shown in the configuration diagram of FIG. 2, a system for processing a DNS message includes an IPv4 node 230 and an IPv6 node in a single network in which different network nodes coexist. Generate and send A and AAAA types of queries to DSN queries (Type A or AAAA types) at node 240 and the IPv4 node 230 or IPv6 node 240, and A and AAAA responses to those queries. A network address translator 210 that transmits a DNS response to the IPv4 node 230 or the IPv6 node 240, and receives and processes A and AAAA queries from the network address translator 210. It is configured with an internal DNS server 220 for transmitting a response to the network address translator 210.

The network address translator 210 is a DNS-ALG NAT that performs an agent function of a node to which a destination node is to be connected.

Referring to the operation and effect of the embodiment of the present invention configured as described above are as follows.

Figure 2a is a signal flow showing the internal node domain name query and response process of an IPv4 node in an embodiment of the present invention.

To explain this, the IPv4 node 230 sets the DNS query to A type and transmits it to the network address translator 210. The network address translator 210 generates the A type query and the AAAA type query to the DNS server 220. send.

In this case, the DNS server 220 transmits the DNS query for the IPv4 domain name by setting the A type and the DNS query for the IPv6 domain name by the AAAA type.

Accordingly, the DNS server 220 transmits a type A DNS response message to the network address translator 210 when the node for the query is an IPv4 node, and an AAAA type DNS response when the node for the query is an IPv4 node.

In other words, the DNS server 220 forwards the response from the node to the network address translator 210 according to the node type to which the DNS query is transmitted.

Accordingly, the network address translator 210 transfers the DNS response from the internal DNS server 220 to the IPv4 node 230 without conversion if the A type is A, and converts the AAA type to the A type if the AAAA type is a response.

2B is a signal flow diagram illustrating an internal node domain name query and response process of an IPv6 node in an embodiment of the present invention.

In FIG. 2B, the DNS query and response of the IPv4 node of FIG. 2A are performed in the same operation as that of the IPv4 node of FIG. 2.

That is, the IPv6 node 240 transmits an AAAA type DNS query for IPv6 to the network address translator 210, and the network address translator 210 generates a DNS query of type A and AAAA type to the internal DNS server 220. If the DNS response of the internal DNS server 220 is AAAA type, the network address translator 210 forwards to the IPv6 node 240 without the message manipulation. In case of, convert to AAAA type which is source query type and deliver.

Meanwhile, the signal flow in FIGS. 2A and 2B will be described with reference to the operation flowcharts of FIGS. 3 to 6.

3 is an operation flowchart showing a DNS query processing process, FIG. 4 is an operation flowchart showing a DNS response processing process, FIG. 5 is an operation flowchart showing a response processing process when a response message exists in the DNS ID table. 6 is an operation flowchart illustrating a case where a packet destination is a DNS server or a query type PTR in FIG. 4, and an AAAA type response process in FIG. 5.

First, the process of FIG. 3 performed by the network address translator 210 will be described.

If a query section exists for the DNS message of the query type, it is determined whether it is an A type query, an AAAA type query, or a PTR type query. The query section is where you write the value you want to ask. For example, if you query www.lg.com, the value of www.lg.com is inserted.

At this time, in case of A type query, a new DNS ID is generated, an ID management table is generated, and an AAAA type query is generated. And, in case of AAAA type query, new DNS ID is generated, ID management table is created, and then A type query is generated. In addition, in case of PTR query type, after converting to PTR address, PTR query is stored, and the changed query session is obtained by obtaining the changed address.

Accordingly, when the query is generated by the above process, if the RR section exists, the A-type and AAAA-type queries are transmitted to the DNS server 220.

In addition, the process of FIGS. 4 to 6 performed by the network address translator 210 will be described.

If there is a query session with respect to the DNS message of the response type, it is determined whether it is an A type query, an AAAA type query, or a PTR type query. Here, the PTR type DNS message generally inserts an IP address into a query session for a PTR type query in a manner of obtaining an IP address and obtaining a DNS name as opposed to a method of asking for a DNS name and obtaining an IP address.

At this time, if the A type or AAAA type query, the ID information is changed to the source query type, and if the response section exists, if the PTR type query, the PTR query information is changed to the source query type if the PTR query information exists in the PTR table. Check that the response section exists. Here, the response section means a place where the actual response value for the query of the DNS message is entered. For example, suppose that a response of 150.150.150.333 is received for a query of www.lg.com. it means.

Then, if the response section is present, if the query type is A or AAAA and if the destination address of the packet is DNS server 220, if the response message for the A or AAAA type query exists in the DNS ID information table, then the source query is A (or If the AAAA type response is A (or AAAA) type response, it is sent as it is. If the source query is A (or AAAA) type AAAA (or A) type response, it is converted to A (or AAAA) type response.

When the packet destination address is not the DNS server 220 or the query type is PTR, if the grant section and the grant section exist, the converted DNS response message is transmitted. Here, the authorization section is where the information of the domain server that performs the DNS service (domain server) enters, and the charging section is where the additional information of the domain server containing the authorization section is entered.

If the destination address of the packet does not exist in the DNS ID information table in response to the A or AAAA type query to the DNS server 220, the response message information is stored and all operations are terminated.

As described in detail above, the present invention proposes an algorithm that performs a function of smoothly calling each other independently of different communication protocols using only domain names in a single network in which both IPv6 and IPv4 coexist, while IPv4 and IPv6 coexist in a single network. It can communicate and improve network performance.

Claims (9)

In an intra network in which an IPv4 node and an IPv6 node coexist, Create and transmit IPv4 and IPv6 type queries for source node queries, check the destination node's response to the query and send them to the source node if they are the same type as the source query. A network address translator (NAT) which converts the data into the same type as the query and transmits it to the source node; And a DNS server for transmitting IPv4 and IPv6 source queries in the network address translator to a destination node and transmitting a response from the destination node to the network address translator. DNS) message processing system. 2. The system of claim 1, wherein the network address translator is configured with a DNS-ALG NAT that performs an agent function of the source node. The network address translator of claim 1, wherein the network address translator is Create a DNS ID table for the query of the source node, if the destination node's response exists in the DNS ID table, send it to the source node with the same type of response as the query of the source node, and the destination node's response exists in the DNS ID table. And if not, to store response message information. The network address translator of claim 1, wherein the network address translator is In the case of the PTR type, a DNS message processing system of an intra-network is configured to convert a PTR address, store a PTR query, and then convert the query session. In an intra network in which an IPv4 node and an IPv6 node coexist, A first step of simultaneously generating an IPv4 and an IPv6 query for an IPv4 or IPv6 query and transmitting it to a target node; And if the response of the target node is of the same type as the source query, responds as it is, and if it is another response, converts to the same type as the source query and performs a second step of responding. The method of claim 5, wherein the first step is A method for processing a DNS message in an intra network, characterized by generating a DNS ID table for an IPv4 or IPv6 type query. The method of claim 5, wherein the first step is In the case of the PTR type, a method of processing a DNS message in an intra network, comprising converting a PTR address, storing a PTR query, and converting a query session. The method of claim 5, wherein the second step is If the response information is present in the DNS ID table, and responds with the same type as the source query, the DNS message processing method in an intra network. The method of claim 5, wherein the second step is In the case of a PTR response, if the authorization section and the charging section exist, transmitting the converted DNS response message to the source node.