KR100644806B1 - Method for automatically configuring address of routers in a multiple hop-based network - Google Patents

Abstract

The present invention relates to a method for automatically setting router addresses by automatically allocating prefixes of routers in a multihop-based network environment in which a plurality of routers are included in a data transmission path between a DHCPv6 server and a host. The method according to the present invention comprises the steps of: (i) requesting a prefix assignment from the DHCPv6 server at the first router; and (ii) setting its own upper interface address using the assigned prefix information. And (iii) generating a prefix pool based on the assigned prefix information, and (iv) selecting one prefix from the created prefix pool and setting its own sub-interface address using the selected prefix. And requesting, at the second router connected to the first router, a prefix assignment to the first router, and repeating steps (ii) to (iv).

Multi-hop-based network, Dynamic Host Configuration Protocol version 6 (DHCPv6), prefix auto assignment

Description

Method for automatically configuring address of routers in a multiple hop-based network}

1 illustrates a network configuration model to which a conventional single hop prefix allocation mechanism using a DHCPv6 prefix option is applied.

Figure 2 (a) shows the IA_PD option format used to request the prefix, and Figure 2 (b) shows the IA_PD prefix option format encapsulated in the IA_PD option to store prefix related information.

Figure 3 is a series of multi-hop based prefix assignment according to the preferred embodiment of the present invention in a network environment consisting of DHCPv6 server 310, upper router 320, lower router 330 and host 340 The process is shown.

Figure 4 illustrates the flow of prefix assignment related message processing between a requesting router and a delegating router in accordance with a preferred embodiment of the present invention.

5 shows the format of an advertising message used in the preferred embodiment of the present invention.

The present invention relates to a method for automatically setting the addresses of routers in a multihop-based network environment. Specifically, a prefix of routers is automatically used by using a Dynamic Host Configuration Protocol version 6 (DHCPv6) server in a multihop-based network environment. A method for automatically setting the addresses of routers by assignment.

Research is actively conducted to automatically provide basic host address generation, default gateway, and DNS configuration information necessary for Internet communication centering on IPv6 working group of Internet Engineering Task Force (IETF), a private international standardization organization. It is becoming. In this regard, Miyakawa and R. Droms have published "Requirements for IPv6 Prefix Delegation" (RFC 3769, June 2004). The RFC 3769 document proposes a mechanism for automatically assigning an address prefix to a subscriber side router.

In addition, as disclosed in "Dynamic Host Configuration Protocol (DHCP) for IPv6" (RFC 3315) published in July 2003 by R. Droms et al., The DHCPv6 protocol is a DHCPv6 server in an IPv6 network environment. In addition to providing IPv6 prefix addresses to hosts, the server has options for providing network configuration information, such as Domain Name System (DNS) and Network Time Protocol (NTP), and DHCPv6 prefix assignment options. This option is used to automatically assign IPv6 prefixes using the server, which can be used to automatically assign prefixes to request routers without the help of the network administrator.

1 illustrates a network configuration model to which a conventional single hop prefix allocation mechanism using a DHCPv6 prefix option is applied. As shown, the customer premises equipment (CPE router 140) installed in the subscriber network is the provider edge of the Internet service provider (ISP) core network 120 to access the Internet. PE) Requests IPv6 prefix assignment using DHCPv6 server multicasting address to router 130. DHCPv6 server 110 existing in ISP network selects available prefixes after verifying and authenticating IPv6 prefix request. There are static, dynamic, and policy-based methods for selecting prefixes in the server, and then the DHCPv6 server 110 sends the DHCPv6 to the CPE router 140. Using an advertisement message, IPv6 prefix information and parameter values assigned to the IA_PD (Identify Association for Delegation) option and the IA_PD-options are set and sent as shown in Fig. 2 (a). The IA_PD option is an option defined for exchanging information related to prefix assignment, and the IA_PD prefix option format shown in Fig. 2 (b) is used as an option for storing prefixes related to IA_PD. Encapsulated in fields A detailed description of these options is detailed in Request for Comments: 3633 "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", filed December 2003 by O. Troan and R.Drom. Since it is prescribed, it will be omitted here.

In order to recheck the selected IPv6 prefix information through the appropriate processing, the CPE router 140 uses the IPv6 Request message to set the IA_PD and IA_PD prefix options included in the DHCPv6 Advertisement message. Send to. After this process is normally performed, the CPE router 140 subnets the IPv6 prefix (typically / 48bit) allocated from the PE router 130 to the / 64bit prefix and transmits its own message through the Router Advertisement (RA) message of the PE router. Send to local network. The host receiving the RA message (eg, subscriber PC) 150 generates its own IPv6 address using an address autoconfiguration mechanism, thereby providing connectivity with an external network.

However, the above-described single hop-based prefix automatic allocation mechanism may be preferably used to automatically set an address to network devices in the home network by automatically assigning its own prefix in a home network environment using xDSL. It is difficult to apply in a large-scale network environment composed of multi-hops. Therefore, it is expected that a prefix auto-allocation mechanism between routers supporting multihops will be required.

Accordingly, an object of the present invention is to provide a method for automatically allocating a prefix of a router in a multi-hop network environment.                         

It is still another object of the present invention to provide a method for automatically configuring router addresses by automatically allocating router prefixes using a DHCPv6 prefix allocation option in a multi-hop network environment.

In order to achieve the above object, according to an aspect of the present invention, there is provided a method for automatically setting the addresses of routers in a network environment in which a plurality of routers are included in a data transmission path between a DHCPv6 server and a host. The method comprises the steps of: (i) requesting a prefix assignment from the DHCPv6 server at a first router; (ii) setting its own upper interface address using the assigned prefix information; iii) generating a prefix pool based on the assigned prefix information, and (iv) selecting one prefix from the created prefix pool and setting its own sub-interface address using the selected prefix. And requesting, at the second router connected to the first router, the prefix assignment to the first router, and repeating steps (ii) to (iv).

(I) requesting the prefix assignment to the DHCPv6 server at the first router and requesting the prefix assignment to the first router at the second router may include requesting the prefix assignment using a DHCPv6 message. .

The requesting the prefix assignment using the DHCPv6 message may include generating and transmitting a DHCP solicit message including a prefix preference information and an identification value thereof to request the prefix information, and the prefix preference information. The method may include receiving a DHCPv6 advertisement message including the prefix information selected on the basis of the prefix information.

Briefly, in the multi-hop IP network environment, an upper router receives an IP prefix address using a DHCP message and then generates a prefix block (prefix pool) to be assigned to its own address and lower router. Characterized in that. After the upper router generates the prefix block to be assigned by itself, the upper router may allocate the prefix when the prefix request using the DHCP message is generated from the lower router.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings. However, the following detailed description is provided for illustrative purposes only and should not be construed as limiting the inventive concept to any particular physical configuration.

Referring to FIG. 3, in a network environment including a DHCPv6 server 310, an upper router 320, a lower router 330, and a host 340, multi-hop based prefix allocation is performed according to an exemplary embodiment of the present invention. A series of procedures is shown. As shown, the network environment to which the present invention is applied includes a DHCPv6 server 310 and routers 320 and 330 and a host 340 that provide client functions. In FIG. 3, for convenience of description, only the upper router R1 320 and one lower router R2 330 associated therewith are illustrated. However, since the upper router R1 320 supports multi-hop, a plurality of lower routers may exist below the upper router R1 320. It will be understood by those skilled in the art that a plurality of routers may also exist under the lower router 330.

In the network environment described above, a process of prefix assignment to routers is as follows.

(1) When Router A 320 is first installed in a network environment, prefix assignment to DHCPv6 server 310 is performed using Router A's link local address (high interface, for example, FE80 :: R1 ') as a source address. Performs an operation of requesting and receiving. A message processing procedure for performing DHCP prefix assignment according to an embodiment of the present invention will be described later with reference to FIG. 4.

(2) Using the prefix (eg 2001: 230: 1/48) received from the DHCPv6 server 310 and the MAC address of the upper interface, generate an IPv6 address of the upper interface of the router R1 320 and assign it to the upper interface. Set it.

(3) Meanwhile, the router A 320 generates a prefix pool based on the local policy based on the prefix information received from the server 310. For example, by adding 4 bits to the prefix information, {2001: 230: 1: 0 :: / 52, 2001: 230: 1: 1 :: / 52, 2001: 230: 1: 2 :: / 52,... You can create a prefix pool like ...}.

(4) Router A 320 selects a prefix to use for its sub-interface address from the generated prefix pool. For example, the first prefix value 2001: 230: 1: 0 :: / 52 is selected from the prefix pool, and the IPv6 address of the lower interface is generated and configured by combining the MAC address of the lower interface of R1 and the selected prefix value. . After generating the set prefix of the sub-interface in the form of / 64, it is advertised to the lower routers with a Router Advertisement (RA) message.

(5) When the lower router B 330 is installed, the router B 330 repeatedly performs the same process as described above in order to receive its own prefix information. At this time, the upper router A 320 receiving the request message will transmit the prefix set in the lower interface as a DHCP reply message. Through this process, the upper interface and the lower interface will form the same network.

(6) The lower router B 330 generates an IPv6 address of its upper interface according to the stateless address automatic generation method using the prefix value received from the upper router A 320 and sets it on the interface. do. Stateless address auto-generation is described in detail by S. Thomson and Obsoletes in the RFC 2462 document (named "IPv6 Stateless Address Auto-configuration") submitted in 1998 by 1971 T. Narten.

Even when the new router is connected to the lower router B 330 or less, it will be understood that the above-described steps (1) to (6) may be repeated to set the address of the new router.

(7) Similar to the above-described process (3), the lower router B 330 generates the prefix pool based on the prefix information received from the upper router A 320. For example, by adding 4 bits to the prefix information, {2001: 230: 1: 1: 1: / 56, 2001: 230: 1: 1: 2: / 56, 2001: 230: 1: 1: 3 :: / 56,.. You can create a prefix pool like ...}.

(8) Similar to the above-described process (4), the router B 330 selects one prefix value from the generated prefix pool and generates its own sub-interface address.

(9) After completing the lowest address setting and automatic allocation of prefix, Router B sets the "M" (ManagedFlag) and "O" (OtherConfig) flag bits in the Router Advertisement message and sends this message to the local network. send. Since the network configuration process proposed in this specification supports automatic networking through DHCP, the "O" flag and the "M" flag will be set to a true value. Here, the "M" flag is a flag for indicating the use of the stateful automatic address setting method. If M is set to a true value, an address may be obtained using a DHCPv6 server. "O (OtherConfig)" is a flag set to obtain information other than an address. When O is set to a true value, DNS information can be obtained using a DHCPv6 server. 5 illustrates a format of an RA message used in an embodiment of the present invention.

(10) Upon receiving the RA message, the host 340 generates its IPv6 address using a stateless automatic address setting scheme. After setting the host address, the host requests the DNS server address by using DHCP information request message. The upper level router that provides DHCPv6 server function provides DNS information to the host by using DHCP reply message on the DNS server address by referring to its setting value when requesting DHCPv6 DNS information. When this process is finished, the host 340 may automatically perform all the configuration processes required for network connection in its IPv6 environment.

Figure 4 illustrates the flow of prefix assignment related message processing between a requesting router and a delegating router in accordance with a preferred embodiment of the present invention. In the above-described process (1) of FIG. 3, it will be understood that the upper router A 320 corresponds to the request router and the PE router (not shown) connected to the DHCPv6 server 310 corresponds to the delegated router. Also, in process (5), it will be understood that the upper router A 320 may correspond to the delegating router and the lower router B 330 may correspond to the requesting router for the prefix allocation of the lower router B 330. The specific message processing procedure is as follows.

410: The requesting router generates a DHCPv6 solicit message. After creating IA_PD for requesting IPv6 prefix information, insert its own identifier (IAID) value. In the IA_PD prefix option, the requesting router may set the prefix preference information (eg, desired prefix length and lifetime) parameter values. Send the generated message to the delegating router side.

420: The delegating router receiving the DHCPv6 solicit message checks the IA_PD option. When the IA_PD prefix option is included, the prefix is selected by referring to parameter information related to the prefix. For example, if there is a preference for the prefix length, the prefix of the requested length is selected.

430: The selected prefix information is transmitted to the request router with the IA_PD prefix option included in the DHCPv6 advertisement message.

440: The request router receiving the DHCPv6 advertisement message checks whether the "NoPrefixAvail" message is included in the status option in the IA_PD option field included in the message. The message "NoPrefixAvail" indicates that the requesting router is not assigned a prefix.

450: If a "NoPrefixAvail" message is included, the requesting router resends the DHCPv6 request message to the delegating router to verify the IPv6 prefix information received in the advertisement message.

460: The delegating router sends a reply message in response to the request message of the requesting router.

According to the present invention, when a new router is installed in a multi-hop network environment such as an enterprise network, when the router is powered on, it can automatically receive its own address and DNS information and provide plug and play network connectivity.

In the foregoing description, the invention has been described in connection with specific embodiments, but modifications, ie, forms and detailed modifications, which fall within the spirit and scope of the appended claims are possible without departing from the spirit and scope of the invention. Will be self-evident. Accordingly, all such modifications will fall within the scope of the invention, and the invention includes the subject matter of the following claims.

Claims (8)

A method for automatically setting router addresses in a network environment in which a plurality of routers are included in a data transmission path between a DHCPv6 server and a host, On the first router, (i) requesting a prefix assignment from the DHCPv6 server; (ii) setting its own upper interface address using the assigned prefix information; (iii) generating a prefix pool based on the assigned prefix information; (iv) selecting one prefix from the generated prefix pool and setting its own sub-interface address using the selected prefix, In a second router connected to the first router, Requesting a prefix assignment from the first router; Repeating steps (ii) to (iv) Automatic address setting method of routers including a. 2. The method of claim 1, wherein (i) requesting the prefix assignment from the DHCPv6 server at the first router and requesting the prefix assignment from the second router at the second router include: assigning a prefix assignment using a DHCPv6 message; Method of automatically setting the address of the router comprising the step of requesting. The method of claim 2, wherein the requesting the prefix assignment using the DHCPv6 message comprises: Generating and transmitting a DHCP solicit message including the prefix preference information and its identification value to request the prefix information, and a DHCPv6 advertisement including the prefix information selected based on the prefix preference information. Receiving a Message Automatic address setting method of routers including a. The method of claim 1, wherein (ii) setting its own upper interface address by using the assigned prefix information, generates an IPv6 address of the upper interface by combining the assigned prefix and the MAC address of the upper interface. Method for automatically setting the address of the router comprising the step of. The method of claim 1, wherein (iii) generating the prefix pool based on the assigned prefix information comprises generating a prefix pool by adding 4 bits to the allocated prefix. . The method of claim 1, wherein (iv) selecting one prefix from the generated prefix pool and setting its own sub-interface address using the selected prefix comprises combining the selected prefix and the MAC address of the sub-interface. Generating an IPv6 address of the sub-interface. The method of claim 1, The second router after the automatic allocation process of the prefix is completed, transmitting a Router Advertisement (RA) message with the "M" (ManagedFlag) and "O" (OtherConfig) flag bits set to the local network; A host connected to the local network receives the RA message and generates its IPv6 address based on a stateless automatic address setting scheme. Method for automatically setting the address of the router further comprising. The router of claim 1, further comprising: requesting a prefix allocation from the third router when the third router is connected to the second router, and repeating steps (ii) to (iv). How to set their address automatically.

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