KR100778348B1 - Method for constructing tunnel forwarding information in line card of ipv6 router - Google Patents

Abstract

A method for constructing tunnel forwarding information in line cards of an IPv6 router is provided to offer an IPv6 packet tunneling function to rapidly convert IPv6 packets into IPv4 packets by receiving a forwarding information message having a tunnel interface, judging whether the received forwarding information message indicates a forwarding information addition request or a forwarding information deletion request, and adding or deleting tunnel information, IPv6 prefix information, and forwarding information respectively for a tunnel table, an IPv6 prefix table, and an IPv6 forwarding table. A line card in an IPv6 router receives a forwarding information message having a tunnel interface(601), and judges whether the received forwarding information message indicates an addition request or a deletion request for associated forwarding information(602). In case it is confirmed that the forwarding information message indicates a forwarding information addition request, the line card confirms whether tunnel information exists(603). If so, the line card increases the channel reference count by 1 and adds associated IPv6 prefix information and forwarding information respectively to an IPv6 prefix table and an IPv6 forwarding table(604,605). In case tunnel information doesn't exist, however, the line card adds associated tunnel information to a tunnel table(606). Then the line card adds associated IPv6 prefix information and forwarding information respectively to the IPv6 prefix table and the IPv6 forwarding table(605).

Description

Method for constructing tunnel forwarding information in line card of IPv6 router}

1 is an exemplary view illustrating a general tunneling process;

2 is an exemplary view showing an internal structure of an IPv6 router to which the present invention is applied;

3 is a structural diagram of an embodiment of a tunnel forwarding information table according to the present invention;

4 is a detailed structural diagram of an embodiment of a tunnel forwarding information table according to the present invention;

5 is a functional explanatory diagram of an IPv6 router to which the present invention is applied;

6 is a flowchart illustrating a method for establishing tunnel forwarding information in a line card of an IPv6 router according to the present invention;

7 is a flowchart illustrating another embodiment of a method of constructing tunnel forwarding information in a line card of an IPv6 router according to the present invention.

* Explanation of symbols for the main parts of the drawings

21: Application Board 22: Line Card

221: IPv4 / IPv6 prefix 222: forwarding information

223 interface information 224 tunnel information

225: IPv4 / IPv6 prefix table 226: IPv4 / IPv6 forwarding table

227: Tunnel Table

The present invention relates to a method of establishing tunnel forwarding information in a line card of an IPv6 router. More particularly, the present invention relates to whether a forwarding information message having a tunnel interface is received from a line card of an IPv6 router. By judging and adding / deleting corresponding tunnel information, IPv6 prefix information, and forwarding information to the tunnel table, IPv6 prefix table, and IPv6 forwarding table, respectively, IPv6 packet tunneling function that converts IPv6 packets into IPv4 packets quickly and quickly at line speed is provided. The present invention relates to a method for establishing tunnel forwarding information in a line card of an IPv6 router.

Currently, the Internet consists of a large IPv4 network and several smaller IPv6 networks. This is because it is difficult to convert the entire IPv4 network to an IPv6 network. Therefore, by building several small IPv6 networks, the size of the IPv6 network is gradually expanded.

In order to transfer the IPv6 packet received from the IPv4-IPv6 network boundary router to the other IPv6 network through the IPv4 network, a process of converting the IPv6 packet into an IPv4 packet and transmitting the IPv6 packet is required.

This will be described in detail with reference to FIG. 1.

As shown in FIG. 1, the terminal 1 103 connected to the IPv6 network 101 generates an IPv6 packet 108. In this case, it can be seen that the destination address (3ffe: 210 :: 10) of the generated packet 108 is the address of the terminal 2 106 in another IPv6 network 104.

The packet 108 generated by the terminal 1 103 is delivered to the IPv4 core network 100 via the IPv4-IPv6 boundary router 1 102, but the IPv4 core network 100 may process the IPv6 packet 108. Can not. Accordingly, the IPv4-IPv6 boundary router 1 102 converts the IPv6 packet 108 into an IPv4 packet 109 to tunnel the IPv4 network.

At this time, the IPv4-IPv6 border router 1 (102) should be a medium speed router that is fast and secure, and in order to do so, a large router having several line cards is required.

Since the IPv6 packet must be tunneled at the line speed in the large router, construction of tunnel forwarding information for efficient packet tunneling is required in the line card of the IPv4-IPv6 boundary router 1 (102).

The present invention has been proposed to solve the above-mentioned problem. As a forwarding information message having a tunnel interface is received at a line card of an IPv6 router, the present invention determines whether the forwarding information is an addition request or a deletion request, and thus, a tunnel table and an IPv6 prefix table. IPv6 router line to provide IPv6 packet tunneling function to convert IPv6 packet into IPv4 packet quickly and quickly at line speed by adding / deleting corresponding tunnel information, IPv6 prefix information, and forwarding information to IPv6 forwarding table, respectively. The purpose is to provide a method of constructing tunnel forwarding information in a card.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a method of establishing tunnel forwarding information in a line card of an IPv6 router, the method comprising: receiving a forwarding information message having a tunnel interface; Determining whether the received forwarding information message is a request for adding or deleting the corresponding forwarding information; The forwarding information adding step of adding corresponding tunnel information, IPv6 prefix information, and forwarding information to the tunnel table, the IPv6 prefix table, and the IPv6 forwarding table, respectively, as a result of the determination; And a forwarding information deleting step of deleting the corresponding tunnel information, the IPv6 prefix information, and the forwarding information from the tunnel table, the IPv6 prefix table, and the IPv6 forwarding table, respectively, as a result of the determination.

In addition, the method of the present invention, the tunnel forwarding information establishment method in the line card of the IPv6 router, comprising the steps of: checking the type of message upon receiving the tunnel interface message; Changing the corresponding tunnel information in the tunnel table when forwarding information for the tunnel interface exists if the tunnel interface change message is found as a result of the checking; Adding the corresponding tunnel interface to the tunnel table if the result of the check is a tunnel interface addition message; And deleting the corresponding tunnel information from the tunnel table and deleting the corresponding IPv6 prefix information and the forwarding information from the IPv6 prefix table and the IPv6 forwarding table, respectively, if the tunnel interface deletion message.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram illustrating an internal structure of an IPv6 router to which the present invention is applied.

As shown in FIG. 2, the IPv6 router to which the present invention is applied includes one application board 21 and a plurality of line cards 1 to n 22.

Here, the application board 21 has a forwarding control function for controlling a plurality of line cards (1 ~ n) 22 to build the same tunnel forwarding information, the line card 22 is the correct forwarding to the hardware It has a forwarding function that manages the forwarding content used to construct information.

In this case, the forwarding contents include IPv4 / IPv6 prefix 221, forwarding information 222, interface information 223, tunnel information 224, and the like, and the hardware information is constructed by using the information.

The hardware information includes an IPv4 / IPv6 prefix table 225, an IPv4 / IPv6 forwarding table 226 and a tunnel information table 227.

3 is a structural diagram of an embodiment of a tunnel forwarding information table according to the present invention.

As shown in FIG. 3, the tunnel forwarding information table according to the present invention includes an IPv4 / IPv6 prefix table, an IPv4 / IPv6 forwarding table, and an IPv4 output information table.

Here, the TCAM 301 storing an IPv6 prefix table stores an IPv6 prefix and a path identifier. Therefore, the IPv6 router searches the TCAM 301 as a Longest Prefix Matching (LPM) type with the received IPv6 packet. The result of the TCAM 301 represents location information in which IPv6 forwarding information is stored in accordance with the prefix in the IPv6 forwarding table 302. The IPv6 forwarding table 302 includes a tunnel identifier, the presence of an incoming IPv4 address, a path identifier and a tunnel information identifier.

Here, the tunnel identifier of the IPv6 forwarding table 302 indicates location information where corresponding tunnel information of the tunnel table 303 is stored. In this case, the presence or absence of the destination IPv4 address separator is required in the IPv6 forwarding table 302 because the destination IPv4 address is included in the IPv6 address in the case of a 6-to-4 tunnel. Accordingly, when such an IPv6 packet comes in, the IPv4 destination address included in the IPv6 packet is used.

However, in the general tunnel, tunnel information 303 includes IPv4 destination address and source address related information to be added to an IPv6 packet. In addition, MTU (Maximum Transmission Unit) and TTL (Time-to-Live) information for tunnel management are included.

Accordingly, the IPv4 packet may be created by adding an IPv4 header to the IPv6 packet using the tunnel information 303. When the IPv4 packet is created, the packet is forwarded to the IPv4 network by referring to the IPv4 prefix table 304 as a normal IPv4 packet.

4 is a detailed structural diagram of an embodiment of a tunnel forwarding information table according to the present invention.

As shown in FIG. 4, the IPv6 prefix information 401 is stored in reverse order of Prefix length. The reason for distinguishing the IPv6 prefix information 401 and the forwarding information 402 is because the hardware is divided into two tables 225 and 226. The reason for separating into two tables in hardware is to use Ternary Content-Addressable Memory (TCAM) when retrieving IPv6 prefixes.

Here, the TCAM is a memory capable of quickly searching for 16-byte IPv6 addresses. Since the smaller the memory size, the better the performance, it is desirable not to put much information in the TCAM. Therefore, it consists of a search IPv6 address and forwarding information in the TCAM.

On the other hand, software should be similar to the hardware table structure to facilitate hardware table management. Therefore, in the present invention, the IPv6 prefix information 401 and the forwarding information 402 are managed separately.

Here, the forwarding information 402 includes a kind of path. It has a pointer to neighbor information 403 when the path is a general IPv6 path, and has a pointer to tunnel information 404 when the path is a tunnel. In this case, multiple paths may share one tunnel information 404.

In the tunnel information 404, there are tunnel types, source and destination addresses to use, and interface identifiers. In this case, the type of tunnel may vary, so the contents of the tunnel information 404 vary according to the type of tunnel.

For example, a 6-to-4 tunnel does not need to specify a destination address because the IPv6 address contains the destination IPv4 address to be used in the tunnel, so that address is available.

In addition, tunnel information 404 includes an interface identifier. The reason is that the application board 21 carries only the interface message and the forwarding message, and since the line card 22 combines this information to build the tunnel information 404, the information about the tunnel is included in the interface message. And includes an interface identifier in the tunnel information 404.

The tunnel information 404 includes a plurality of path identifiers, which can be changed when the tunnel information is changed so that the state of the interface information 405 and the forwarding information 402 and the tunnel information 404 can be changed. To match. The interface information 405 includes interface type and interface related information.

5 is a functional explanatory diagram of an IPv6 router to which the present invention is applied.

First, the operation processor 51 has a function to help the operator to set the necessary functions to operate the router.

The application processor 52 generates the forwarding information by using the routing information set by the operator and the routing information generated by the routing protocol.

At this time, the application processor (AP) 52 receives the interface information set by the routing processor 521 and the operator for generating the routing information, and transmits the interface message including the interface information to the software function of the router system and transmits to the tunnel interface. An interface manager 522 for generating information about the network, and an IPv4 / IPv6 route management function for transmitting route information to all line cards, and tunnel path management for setting tunnel information in the application processor 52 kernel; And a forwarding control unit 523 for performing a function.

In this case, the forwarding control unit 523 may generate an IPv6 packet at a router and tunnel the IPv4 network, so that the forwarding control unit 523 may use the kernel contents of the application processor (AP) 501 and the hardware function 511 of the line card 504. Match them together so that you can handle the same for the tunnel.

Meanwhile, the line card 53 constructs the IPv6 TCAM 514, the IPv4 TRIE 515, and the IPv4 / IPv6 forwarding 516 table of the hardware by using the forwarding information received from the forwarding control unit 523, and interfaces the tunnels. When forwarding information is created in the server, it is stored in the IPv6 forwarding table and stored in the tunnel table.

FIG. 6 is a flowchart illustrating a method of establishing tunnel forwarding information in a line card of an IPv6 router according to the present invention, and illustrates a process of adding / deleting forwarding information.

First, when the new tunnel forwarding information is added or deleted, the routing processor 521 constructs the tunnel forwarding information and transmits the tunnel forwarding information to the forwarding controller 523. Then, the forwarding control unit 523 reflects the received tunnel forwarding information to the AP kernel and transfers it to all the line cards 53.

Subsequently, the line card 53 receives a forwarding information message (a message including forwarding information and whether to add / delete) having a tunnel interface (601), and determines whether to add or delete the corresponding forwarding information (602). ). At this time, if the interface information does not exist in the received tunnel forwarding information, the tunnel forwarding information is deleted. If the IPv4 / IPv6 interface, the normal IPv4 / IPv6 forwarding information is processed.

As a result of the determination (602), it is checked whether tunnel information exists if the forwarding information is added (603).

As a result of the check 603, if there is tunnel information, the number of tunnel references is increased and then the corresponding IPv6 prefix information and forwarding information are added to the IPv6 prefix table 225 and the IPv6 forwarding table 226, respectively (604 and 605). At this time, the tunnel reference number is increased by one.

As a result of the check 603, if the tunnel information does not exist, after the tunnel information is added to the tunnel table 227 (606), the process proceeds to the step "605" and the IPv6 prefix table 225 and the IPv6 forwarding table ( Corresponding IPv6 prefix information and forwarding information are added to 226, respectively (605).

As a result of the determination (602), if the deletion request of the forwarding information, the tunnel information is searched to determine the forwarding number (tunnel reference number) referring to the tunnel information (607).

As a result of checking 607, if the number of tunnel references exceeds 1, the number of tunnel references is reduced and then the corresponding IPv6 prefix information and forwarding information are deleted from the IPv6 prefix table 225 and the IPv6 forwarding table 226, respectively (608 and 609). ). At this time, the tunnel reference number is decreased by one.

As a result of the check 607, if the number of tunnel references is 1, after deleting the corresponding tunnel information from the tunnel table 227 (610), the process proceeds to the " 609 " process, and then the IPv6 prefix table 225 and the IPv6 forwarding table 226. In operation 609, corresponding IPv6 prefix information and forwarding information are deleted. Here, the reference number is a natural number including 0, and when 0 means that there is no tunnel to refer to.

7 is a flowchart illustrating another embodiment of a method of constructing tunnel forwarding information in a line card of an IPv6 router according to the present invention, illustrating a process of adding / changing / deleting tunnel interface information.

First, as the operation processor 51 adds / deletes the tunnel interface, the tunnel processor transmits the tunnel information to the application processor 52. Then, the application processor 52 reflects the received tunnel information to the AP kernel and delivers the interface message containing the tunnel interface information to the plurality of line cards 53.

Thereafter, as the line card 53 receives the tunnel interface message (701), the line card 53 checks the type of the message (702).

As a result of the check 702, if a tunnel interface change message is present, corresponding tunnel information is changed in the tunnel table 227 as forwarding information for the tunnel interface exists (703). At this time, if the tunnel information does not exist, it ends. Here, the reason for terminating when the forwarding information for the tunnel interface does not exist is meaningful when the tunnel information exists. If there is only a tunnel interface and no forwarding information for the tunnel, there is no need to store tunnel information about it.

As a result of the check 702, if the tunnel interface addition message is added, the corresponding tunnel interface is added to the tunnel table 227 (704).

As a result of the check 702, if the tunnel interface deletion message is deleted, the corresponding tunnel information is deleted from the tunnel table 227, and then the corresponding IPv6 prefix information and forwarding information are deleted from the IPv6 prefix table 225 and the IPv6 forwarding table 226, respectively. (705).

Through this process, the present invention establishes IPv6 tunnel forwarding information on a line card of a large IPv4-IPv6 border router, so that the router can tunnel IPv6 packets to the IPv4 network quickly and effectively at a line speed.

In addition, it is possible to tunnel IPv6 packets in the state change of the router by matching the tunneling information established in the line card.

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention as described above, in response to receiving a forwarding information message having a tunnel interface in the line card of the IPv6 router, it is determined whether to add or delete the corresponding forwarding information, respectively, in the tunnel table, IPv6 prefix table, IPv6 forwarding table By adding / deleting corresponding tunnel information, IPv6 prefix information, and forwarding information, it is possible to provide an IPv6 packet tunneling function for converting IPv6 packets into IPv4 packets quickly and quickly at line speed.

Claims (8)

In the tunnel forwarding information construction method in the line card of the IPv6 router, Receiving a forwarding information message having a tunnel interface; Determining whether the received forwarding information message is a request for adding or deleting the corresponding forwarding information; The forwarding information adding step of adding corresponding tunnel information, IPv6 prefix information, and forwarding information to the tunnel table, the IPv6 prefix table, and the IPv6 forwarding table, respectively, as a result of the determination; And The forwarding information deleting step of deleting the corresponding tunnel information, the IPv6 prefix information, and the forwarding information from the tunnel table, the IPv6 prefix table, and the IPv6 forwarding table, if the request for deleting the forwarding information is determined. Tunnel forwarding information establishment method in the line card of the IPv6 router comprising a. The method of claim 1, The forwarding information adding step, A first checking step of confirming whether tunnel information exists if the forwarding information is added as a result of the determination; If tunnel information exists, increasing tunnel reference number and adding corresponding IPv6 prefix information and forwarding information to the IPv6 prefix table and the IPv6 forwarding table, respectively; And If tunnel information does not exist, adding corresponding tunnel information to the tunnel table, and then adding corresponding IPv6 prefix information and forwarding information to the IPv6 prefix table and the IPv6 forwarding table, respectively; Tunnel forwarding information establishment method in the line card of the IPv6 router comprising a. The method of claim 1, The deleting of the forwarding information, A second checking step of retrieving the number of forwarding information referring to the tunnel information by searching for tunnel information when the deletion request of the forwarding information is determined; If the number of tunnel references is greater than 1, reducing the number of tunnel references and deleting corresponding IPv6 prefix information and forwarding information from the IPv6 prefix table and the IPv6 forwarding table, respectively; And If the number of tunnel references is 1, deleting the corresponding tunnel information from the tunnel table and deleting corresponding IPv6 prefix information and forwarding information from the IPv6 prefix table and the IPv6 forwarding table, respectively; Tunnel forwarding information establishment method in the line card of the IPv6 router comprising a. In the tunnel forwarding information construction method in the line card of the IPv6 router, Confirming the type of message upon receiving the tunnel interface message; Changing the corresponding tunnel information in the tunnel table when forwarding information for the tunnel interface exists if the tunnel interface change message is found as a result of the checking; Adding the corresponding tunnel interface to the tunnel table if the result of the check is a tunnel interface addition message; And If the tunnel interface deletion message indicates that the tunnel information is deleted, deleting the corresponding tunnel information from the tunnel table and then deleting the corresponding IPv6 prefix information and the forwarding information from the IPv6 prefix table and the IPv6 forwarding table, respectively. Tunnel forwarding information establishment method in the line card of the IPv6 router comprising a. The method according to any one of claims 1 to 4, The IPv6 prefix table, Include the IPv6 Prefix Length, IPv6 Address, and Route Identifier fields, IPv6 prefix information is stored in the reverse order by prefix length, tunnel forwarding information construction method in the line card of the IPv6 router. The method of claim 5, The IPv6 forwarding table is A method of constructing tunnel forwarding information in a line card of an IPv6 router, comprising a path identifier, a path type, an IPv6 prefix, and a neighbor / tunnel information pointer field. The method of claim 6, The tunnel table is, And a tunnel identifier, a tunnel type, a source address, a destination address, a reference number, a route identifier, and an interface identifier. The method of claim 7, wherein The IPv6 prefix table and the IPv6 forwarding table, Tunnel forwarding information is built in the line card of an IPv6 router, which is a memory capable of quickly retrieving 16-byte IPv6 addresses and is stored in TCAM (Ternary Content-Addressable Memory), which shows better performance as the memory size is smaller. Way.

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