KR100714807B1 - Method and apparatus for managing neighbor table of subscriber card in software forwarding based IPv6 router system - Google Patents

Abstract

The present invention relates to a method of establishing and managing a neighbor table of a subscriber card in a software forwarding based Internet Protocol Version 6 (IPv6) router system. Specifically, the method of building a neighbor table of a subscriber card according to the present invention comprises the steps of: broadcasting a first request message for requesting the download of a neighbor table to another subscriber card in the router system upon initial installation or restart of the subscriber card; Receiving a response message for the first request message from the other subscriber card, and transmitting a second request message for requesting neighbor table information to the subscriber card that transmitted the first response message received among the received response messages. And receiving a response message to the second request message and constructing a neighbor table in the kernel by using the neighbor table information included in the response message.

The present invention can be used to efficiently construct a neighbor table in a subscriber card of a software forwarding based IPv6 router system.

Software forwarding, routers, subscriber cards, neighbor discovery protocol

Description

Method and Apparatus for managing a neighbor table of a subscriber card in IPv6 software forwarding router system in an IP6 router system based on software forwarding

1 is a configuration diagram of a software forwarding based IPv6 router system to which the present invention is applied.

FIG. 2 is a detailed configuration diagram of the subscriber card shown in FIG.

3 is a diagram illustrating a procedure of downloading a neighbor table from another subscriber card upon initial installation or restart of a subscriber card according to one embodiment of the present invention.

4 is a diagram illustrating a procedure for broadcasting a neighbor entry from a subscriber card to another subscriber card according to an embodiment of the present invention.

5 is a flowchart illustrating a neighbor table management method of a subscriber card according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: software forwarding based IPv6 router system

110: system management card

120: application card

130, 140: subscriber card

150: Ethernet (control network)

160: Fabric Card

131: routing information management block

132 interface management block

133: address status management block

134: Neighbor Discovery Protocol management block

135: kernel

136: cluster interface

The present invention relates to a method of managing a neighbor table of a subscriber card in a software forwarding-based Internet Protocol Version 6 (IPv6) router system. A method of building and managing the same neighbor table for the entire system by passing a neighbor entry for a local interface of to another subscriber card.

In the conventional IPv4-based router system, the packet forwarding function of the kernel should be used when adding a function of forwarding packets in a software manner to provide IPv6 services without changing hardware. In this case, in order to use the packet forwarding function of the kernel, neighbor entries of all subscriber cards must exist in the neighbor table of the kernel, but there is a problem that only the neighbor entry for the local interface can be constructed in the kernel.

Accordingly, an object of the present invention is to provide a method for efficiently constructing a neighbor table in a kernel by downloading a neighbor table from another subscriber card at the time of installing or restarting a subscriber card.

Another object of the present invention is to provide a method for managing the same neighbor table for the entire system by delivering a neighbor entry for the local interface of the subscriber card to another subscriber card.

According to a first aspect of the present invention for achieving the above object, there is provided a neighbor table construction method of the subscriber card in an IPv6 router system having a plurality of subscriber cards. The method includes broadcasting, upon initial installation or restart of a subscriber card, a first request message requesting the download of a neighbor table to another subscriber card in the system, and for the first request message from the other subscriber card. Receiving a response message, transmitting a second request message for requesting neighbor table information to the subscriber card that transmitted the first response message received among the received response messages, and responding to the second request message. Receiving a message and building a neighbor table in the kernel by using the neighbor table information included in the response message.

According to a second aspect of the present invention, there is provided a neighbor table management method for a subscriber card in an IPv6 router system having a plurality of subscriber cards. The method includes receiving new neighbor entry information from a kernel and broadcasting the neighbor entry information to another subscriber card if the received neighbor entry is an entry belonging to a local interface.

According to a third aspect of the present invention, there is provided a neighbor table management method for a subscriber card in an IPv6 router system having a plurality of subscriber cards. The method includes receiving new neighbor entry information from another subscriber card and setting the neighbor entry in a kernel if the received neighbor entry is not a neighbor entry for a local interface.

According to a fourth aspect of the present invention, there is provided a subscriber card installed in a software forwarding IPv6 router system, the subscriber card comprising: a kernel for forwarding IPv6 data packets using a routing table and a neighbor table; An NDP management block that downloads a neighbor table from another subscriber card in the IPv6 router system and builds it in the kernel upon initial installation or restart, and monitors the kernel's neighbor table to broadcast local neighbor entry information to another subscriber card. do.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of an IPv6 router system based on software forwarding to which the present invention is applied. As shown in FIG. 1, the IPv6 router system 100 includes a system management card 110, an application card 120, a plurality of subscriber cards 130 and 140, and Ethernet 150 and IPv6 for communication between them. Fabric card 160 that performs processing and transmission of packets.

The system management card 110 manages software and hardware of the entire router system and processes operator commands. The application card 120 performs a routing protocol to transfer routing information to each subscriber card 130 and 140, and the subscriber cards 130 and 140 receive routing information from the application card 120 to generate a routing table in the kernel. Build.

FIG. 2 is a detailed configuration diagram of the subscriber card shown in FIG. 1. As shown, the subscriber card 130 includes a routing information management block 131, an interface management block 132, an address state management block 133, an NDP management block 134, a kernel 135, and a cluster interface 136. ).

The routing information management block 131 receives the routing information from the application card 120 to build a routing table in the kernel, and the interface management block 132 receives the interface information from the application card 120 to receive the kernel. Performs the function of setting the interface to. The address state management block 133 manages the address state by performing IPv6 address setting and Duplicate Address Detection (DAD) for each interface configured in the kernel.

The NDP management block 134 is a block that downloads a neighbor table from another subscriber card upon initial installation or restart of a subscriber card, monitors the kernel's neighbor table, and broadcasts local neighbor entry information to another subscriber card. It will be referred to as a characteristic component of the present invention.

The kernel 135 performs software forwarding of IPv6 data packets using the routing table and the neighbor table, and the cluster interface 136 manages the interfaces of all subscriber cards in the system within the kernel 135. do.

3 is a diagram illustrating a procedure of downloading a neighbor table from another subscriber card at initial installation or restart of a subscriber card according to an embodiment of the present invention. In the figure, a process of downloading the neighbor table from the subscriber card 2 to the subscriber card 1 at the time of initial installation or restart is described as an example.

First, when subscriber card 1 is initially installed or restarted, the NDP management block of subscriber card 1 sends a DownLoad_Request message with the flag set to DOWNLOAD_HELP to determine which subscriber card to download the neighbor table from all subscriber cards (eg, subscriber card 2, Broadcast to subscriber card N) (310).

The NDP management blocks of the subscriber cards receiving the message M1 transmit a NDP_DownLoad_Reply message carrying their card number to the subscriber card 1 (320, 320 '...). The subscriber card 1 sets the subscriber card number (in this example, the subscriber card 2) included in the first received NDP_DownLoad_Reply message as the subscriber card to be downloaded.

Next, subscriber card 1 transmits an NDP_DownLoad_Request message whose flag value is set to DOWNLOAD_NEED to subscriber card 2 to indicate that download of a neighbor entry is required (330). In response, the subscriber card 2 loads the neighbor entry number and the neighbor entry list included in its neighbor table in the NDP_DownLoad message and transmits it to the subscriber card 1 (340). In this case, the neighbor entry information includes an IPv6 address, a MAC address, and an interface identifier.

4 illustrates a procedure of broadcasting a neighbor entry from a subscriber card to another subscriber card according to an embodiment of the present invention. In the drawing, a process of exchanging neighbor entry information between subscriber card A and subscriber card B is described as an example.

After the neighbor table information is downloaded from another subscriber card at the time the subscriber card is installed or restarted, the NDP block of the subscriber card monitors the netlink by opening the kernel and netlink and executing the neighbor entry monitoring thread ( 410, 410 '). By monitoring the netlink between the NDP management block and the kernel, it is possible to determine whether a new neighbor entry is set in the kernel's neighbor table.

Subsequently, the NDP management block receives new neighbor entry information obtained from the kernel through netlink monitoring (420 and 420 '). In contrast, the NDP management block determines whether the neighbor entry received from the kernel is an entry belonging to the local interface, and if the neighbor entry is local, the neighbor entry information is loaded in the NDP_Entry message and broadcasted to another subscriber card (430, 430 '). . On the other hand, if it is determined that the neighbor entry does not belong to the local interface, it is ignored (420 ').

On the other hand, upon receiving an NDP_Entry message including neighbor entry information from another subscriber card, it is determined whether the corresponding neighbor entry is a neighbor entry for the local interface. If it is local, ignore it and if not, set the neighbor entry in the kernel via netlink (440, 440 ').

5 is a flowchart illustrating a neighbor table management method of a subscriber card according to an embodiment of the present invention.

As shown in FIG. 5, when the subscriber board is installed or restarted (501), an NDP_DownLoad_Request message is sent to another subscriber card (502).

In response, upon receipt of an NDP_DownLoad_Reply message containing a subscriber card number from another subscriber card (503), the subscriber card that sent the first received message is set to a subscriber card (hereinafter referred to as a "download card") to be downloaded (504). ).

Next, the NDP_DownLoad_Request message is transmitted to the download card (505), and the NDP_DownLoad message including the number of neighbor entries and the entry list is received (506) from the download card.

A neighbor entry table is built in the kernel according to the received information (507).

When the neighbor table download process by the initial installation or restarting is completed, the netlink is opened to monitor the neighbor table of the kernel (508).

When a new neighbor entry is received from the kernel (509), it is determined whether it is a neighbor entry belonging to the local interface (510). If it is a local neighbor entry, the neighbor entry information is loaded into NDP_Entry to be transmitted to another subscriber card (511).

On the other hand, if an NDP_Entry message containing neighbor entry information is received from an NDP management block of another subscriber card (512), it is determined whether the corresponding neighbor entry is a neighbor entry for a local interface (513). If it is local, ignore it and if not, set the neighbor entry to the kernel (514).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

According to the present invention, since the kernels of all subscriber cards of the software-forwarding IPv6 router system have the same neighbor information of the system-wide interface, efficient IPv6 packet forwarding is possible.

Claims (12)

In the IPv6 router system having a plurality of subscriber cards, the method of building a neighbor table of the subscriber card, the method, Broadcasting a first request message requesting the download of a neighbor table to another subscriber card in the system upon initial installation or restart of the subscriber card; Receiving a response message to the first request message from the other subscriber card; Transmitting a second request message for requesting neighbor table information to a subscriber card transmitting the first received response message among the received response messages; Receiving a response message to the second request message and constructing a neighbor table in the kernel using the neighbor table information included in the response message; The neighbor table establishment method of the subscriber card comprising a. The method of claim 1, wherein the method is performed in a neighbor discovery protocol (NDP) management block of a subscriber card. The method of claim 1, wherein the first request message is a Download_Request message with a flag set to DOWNLOAD_HELP. The method of claim 1, wherein the response message to the first request message is an NDP_Download_Reply message, and the NDP_Download_Reply message includes the number of the subscriber card that transmitted the message. The method of claim 1, wherein the second request message is an NDP_Download_Request message with a flag set to DOWNLOAD_NEED. The method of claim 1, wherein the entry of the neighbor table included in the response message to the second request message includes an IPv6 address, a MAC address, and an interface identifier. In the IPv6 router system having a plurality of subscriber cards in the neighbor table management method of the subscriber card, the method, Receiving new neighbor entry information from the kernel, If the received neighbor entry is an entry belonging to a local interface, broadcasting the neighbor entry information to another subscriber card; The neighbor table management method of the subscriber card comprising a. 8. The method of claim 7, wherein the method further comprises: opening a netlink between the NDP management block and the kernel of the subscriber card and monitoring the netlink to determine that a new neighbor entry is established in the kernel. How to manage neighboring tables. 8. The method of claim 7, wherein if the received neighbor entry is not an entry belonging to a local interface, the neighbor entry is ignored. In the IPv6 router system having a plurality of subscriber cards in the neighbor table management method of the subscriber card, the method, Receiving new neighbor entry information from another subscriber card; Setting the neighbor entry to a kernel if the received neighbor entry is not a neighbor entry for a local interface The neighbor table management method of the subscriber card comprising a. 12. The method of claim 10, wherein the received neighbor entry is ignored if the received neighbor entry is a neighbor entry for a local interface. In a subscriber card installed in a software forwarding IPv6 router system, the subscriber card, A kernel that forwards IPv6 data packets using routing tables and neighbor tables, NDP management that downloads a neighbor table from another subscriber card in the IPv6 router system and builds it in the kernel upon initial installation or restart of the subscriber card, and monitors the kernel's neighbor table to broadcast local neighbor entry information to other subscriber cards. block Subscriber card comprising.

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