WO2016078235A1

WO2016078235A1 - Network translation realization method and apparatus for transiting to ipv6 on the basis of pant

Info

Publication number: WO2016078235A1
Application number: PCT/CN2015/072456
Authority: WO
Inventors: 路瑞强; 耿大伟; 许丽丽
Original assignee: 中兴通讯股份有限公司
Priority date: 2014-11-18
Filing date: 2015-02-06
Publication date: 2016-05-26
Also published as: CN105681481A

Abstract

Disclosed in the present invention are a network translation realization method and apparatus for transiting to IPv6 on the basis of PNAT. The method is applied to the network access apparatus CPE which is between a LAN side and a WAN side, and comprises the steps of: obtaining a message; performing a Prefix Network Address Translation (PNAT) on the message, and performing the corresponding uplink or downlink transmission on the translation result. With the present invention, the PNAT function is realized on the network access equipment CPE to achieve the transition to IPv6, and thus avoids the technical problems in prior art and solves the problems of the need to modify a great number of hosts and low feasibility which exist in the host apparatus modification solution in the prior art.

Description

Network conversion implementation method and device based on PNAT to IPv6 transition

Technical field

The present invention relates to the field of communications, and in particular to a network conversion implementation method and apparatus based on PNAT (Prefix Network Address Translation) to IPv6 (Internet Protocol Version 6, Internet Protocol Version 6).

Background technique

With the rapid development of Internet technology, the current IPv4 (Internet Protocol Version 4, Internet Protocol Version 4) address resources are increasingly exhausted. Under the current situation, the migration of IPv4 to IPv6 has become inevitable. However, due to the widespread use of IPv4 networks, IPv6 is unlikely to completely replace IPv4 in the short term. Therefore, the two network technologies will coexist for a long time until IPv4 transitions completely to IPv6.

Among them, how to realize the interconnection and smooth transition between IPv4 network and IPv6 network is an important issue that needs to be resolved during the transition period.

The method of transition to IPv6 began in 1994 with the IETF (Internet Engineering Task Force) NGTRAN working group. In 1996, 6Bone was established for experiments. In 1998, the first group of IPv6 standard RFCs was released. (Request For Comments , request for amendments), the NGTRAN working group was closed in 2003, and the transition technologies at that time mainly included: double stack, tunnel and translation technology. Until 2007, with the introduction of a series of new transition technologies such as DS-Lite, CGN, A+P, NAT64, and IVI, the IETF re-agreed in the fall of 2008 to develop new translation and tunneling technologies.

Currently, the industry has been modifying the application or modifying the host in order to support IPv6 during the transition period. Since IPv6 mainly solves the problem of the network layer, it is currently adopted to modify the application to support IPv6. It is difficult and enthusiasm is not high. People hope that the problem on the network side is still solved by the network side solution, rather than relying on the application layer to solve the problem of the network layer. At the same time, due to the recent trend of operators customizing their own mobile phones and developing mobile operating systems, how to promote the IPv4 network deployment while ensuring the normal communication of IPv4 applications, that is, IPv6 backward compatible IPv6 transition technology solutions In the prior art, a host-based IPv6 transition technology PNAT is proposed to ensure the normal communication of the traditional IPv4 application while deploying IPv6, so as to achieve transparency to the application.

The Chinese Patent Application No. CN201010590735.6 discloses a network address translation method, device and system, the method comprising: receiving an IPv4 address allocation request sent by a host device using IPv6, the IPv4 The address allocation request is used to indicate that the requested IPv4 address is used for the prefix network address translation PNAT; according to the IPv4 address allocation request, an unallocated IPv4 address is obtained from the IPv4 address pool and allocated to the host device; the allocated IPv4 The address is returned to the host device, so that the host device accesses the peer device using IPv4 according to the allocated IPv4 address.

It can be seen that the patent scheme focuses on the transformation of the IPv6 host device, and uses the prefix information to complete the mutual conversion between the IPv4 header and the IPv6 header on the IPv6 host. However, the modification of the host device has the problem of not being feasible, and at the same time, There is a need to modify a large number of host devices, resulting in low efficiency and high cost.

Summary of the invention

In order to solve the problem that the modification of the host device is not feasible and the problem of the host device is required to be modified in a large amount, the purpose of the embodiment of the present invention is to provide a network conversion implementation method and apparatus based on PNAT to IPv6 transition.

In order to achieve the object of the present invention, the embodiments of the present invention are implemented by the following technical solutions:

A network conversion implementation method based on PNAT to IPv6 transition, which is applied to a network access device CPE (Customer Premise Equipment) located between a LAN (Local Area Network) and a WAN (Wide Area Network) On, including the following steps:

Obtain a message;

Performing a prefix network address translation PNAT on the packet, and performing a corresponding uplink or downlink transmission on the conversion result.

Preferably, for the uplink IPV4 message, the prefix network address translation PNAT includes:

The uplink IPV4 packet is converted into an uplink IPv6 packet.

Preferably, the uplink IPV4 message is generated by the LAN side or generated locally.

Preferably, for the downlink IPV6 message, the prefix network address translation PNAT includes:

Converting the downlink IPV6 packet into a downlink IPv4 packet;

The downlink IPv4 packet is placed in the IPv4 protocol stack to wait for route forwarding.

Preferably, the prefix network address translation PNAT rule is added to the PREROUTINGHOOK attachment point of the ip6tables framework to convert the downlink IPV6 packet into a downlink IPv4 packet.

A device for implementing a network switching device based on the transition from PNAT to IPv6, which is deployed on the network access device CPE between the LAN side and the WAN side, and includes:

a first transmission module, configured to acquire a message;

a PNAT module, configured to perform prefix network address translation on the packet;

The second transmission module is configured to perform corresponding uplink or downlink transmission by using the conversion result provided by the PNAT module.

Preferably, when the first transmission module acquires an uplink IPV4 packet, the PNAT module is configured to convert the uplink IPV4 packet into an uplink IPv6 packet.

Preferably, when the first transmission module obtains the downlink IPV6 packet, the PNAT module is configured to convert the downlink IPV6 packet into a downlink IPv4 packet, and further configured to put the downlink IPv4 packet Enter the IPv4 protocol stack to wait for route forwarding.

Preferably, the PNAT module is further configured to add a prefix network address translation PNAT rule on the PREROUTINGHOOK attachment point of the ip6tables framework, so as to convert the downlink IPV6 packet into a downlink IPv4 packet.

A network access device (CPE), which includes a network switching implementation device based on PNAT to IPv6 transition as described above, and the device is deployed on a network access device CPE located between the LAN side and the WAN side, and includes:

a first transmission module, configured to acquire a message;

A system comprising:

LAN side;

WAN side;

And the network access device CPE located between the LAN side and the WAN side as described above, and specifically, the network access device CPE includes a PNAT-to-IPv6-based network switching implementation device as described above, the device deployment On top of the network access device CPE located between the LAN side and the WAN side, including:

a first transmission module, configured to acquire a message;

Compared with the traditional dual-stack technology and the tunnel technology transition solution, the embodiment of the present invention is superior, and the dual-stack technology itself also consumes the IPv4 address, which leads to the exhaustion of the IPv4 address in the process of implementing the dual-stack migration scheme. The tunneling technology must have the symmetric use of the tunnel peer device to complete the transmission of the IPv4 payload in the IPv6 network. The application scenario is limited and the mutual access between the IPv4 host and the peer IPv6 network cannot be completed. . In addition, the embodiment of the present invention implements a PNAT function on the network access device CPE to implement IPv6 access, as compared with the technical solution for directly modifying the host device and implementing the prefix network address translation (PNAT) on the host device. In the transition, the technical problems existing in the prior art are avoided, and the problem that the modification of the host device in the prior art needs to be modified for a large number of hosts and the feasibility is not high is solved.

DRAWINGS

FIG. 1 is a schematic flowchart of a method for implementing network transition based on PNAT to IPv6 according to an embodiment of the present invention;

2 is a schematic flowchart of a packet forwarding process of a CPE according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a device for implementing network transition based on PNAT to IPv6 according to an embodiment of the present disclosure;

4 is a schematic diagram of a system network topology according to an embodiment of the present invention;

FIG. 5 is a schematic flowchart of processing a DNS packet when a PC accesses an IPv4 network according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a process of processing a DNS packet when a PC accesses an IPv6 network according to an embodiment of the present invention.

The implementation, functional features and excellent effects of the object of the present invention will be further described below in conjunction with the specific embodiments and the accompanying drawings.

detailed description

The technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments to enable those skilled in the art to understand the invention. .

Referring to FIG. 1, an embodiment of the present invention provides a network switching implementation method based on PNAT to IPv6, which is applied to a network access device CPE located between a LAN side and a WAN side, and includes the following steps:

S10. Obtain a message;

S20: Perform prefix network address translation (PNAT) on the packet, and perform a corresponding uplink or downlink transmission on the conversion result.

In this embodiment, the method implements the PNAT technology on the network access device CPE, and re-encapsulates the IPv4 packet provided by the IPv4 host on the LAN side into an IPv6 packet, so that the IPv4 host can communicate through the IPv6 network. Or the IPv6 packet obtained from the WAN side is converted into an IPv4 packet and provided to the LAN side IPv4 host.

In the specific implementation, the DNS proxy function of the network access device CPE is modified: the DNS packet including the class A request sent by the host device on the LAN side can be extended to the AAAA class request, and sent with different ID numbers; A side AAAA response packet is used to map or translate the IPv6 address into an IPv4 address, and the response packet is translated into a Class A packet and forwarded to the LAN side.

By adopting the invention, the host device can be modified without interchanging the host device, and the interconnection between the IPv4 network and the IPv6 network can be realized.

In this embodiment, for the uplink IPV4 packet, the prefix network address translation PNAT includes:

(1) The uplink IPV4 packet is converted into an uplink IPv6 packet. In this embodiment, the uplink IPV4 packet is generated by the LAN side or locally.

The network access device CPE processes the uplink IPV4 packet: the PNAT0 virtual device is used to receive all the IPv4 packets forwarded by the LAN and the local application, and translate the packets into IPv6 packets according to the requirements of the relevant RFC. Forward.

In this embodiment, for the downlink IPV6 packet, the prefix network address translation PNAT includes:

(1) Add a prefix network address translation PNAT rule on the PREROUTINGHOOK connection point of the ip6tables framework, and convert the downlink IPV6 packet into a downlink IPv4 packet; wherein the ip6tables framework is a configuration framework provided by the Linux system, and the PREROUTINGHOOK connection point Is a mount point under the ip6tables framework.

(2) Put the downlink IPv4 packet into the IPv4 protocol stack to wait for route forwarding.

In this embodiment, referring to FIG. 2, the step of the network access device CPE performing prefix network address translation (PNAT) on the DNS packet includes (as shown by the broken line in FIG. 2):

(1) Obtain a DNS request packet sent by the host on the LAN side and send it to the DNS proxy process;

(2) The DNS proxy process parses the DNS request packet, and if the DNS request packet is parsed as an A record request packet, it is converted into an AAAA record packet, and then routed to the PNAT0 virtual device; The PNAT0 virtual device is used to translate and convert IPv4 packets to IPv6 packets.

(3) After receiving the AAAA record message, the PNAT0 virtual device uses the Local Internet Register (LIR) prefix and the Well-Known Prefix (WKP) prefix to specify the source IP address and destination of the IPv4 packet. The IP is converted to an IPv6 address, and the IPv4 header is converted into an IPv6 header, which is then processed by the IPv6 protocol stack;

(4) After receiving the IPv6 packet converted by the PNAT0 virtual device, the IPv6 protocol stack is forwarded to the outbound interface nbif virtual device, and forwards the IPv6 packet to the WAN side according to the sending function of the outbound interface nbif virtual device;

(5) Obtaining an AAAA response message replied by the WAN side;

(6) Restoring the AAAA response packet to a corresponding IPv4 packet, and forwarding the packet to the IPv4 protocol stack;

(7) The IPv4 packet is routed to the DNS proxy process in the IPv4 protocol stack. The DNS proxy process parses the IPv4 packet, converts the AAAA record into an A record, and restores the IPv6 address to the corresponding IPv4 address.

(8) Forward the DNS response message containing the A record to the LAN side host.

In this embodiment, the LAN-side HOST host performs a prefix network address translation PNAT process on a data packet such as a Transmission Control Protocol/User Datagram Protocol (TCP/UDP) (as shown in FIG. 2). Shown in the solid line) includes:

The forwarding process of data packets such as TCP/UDP is similar to the DNS packet in 1). The difference is that the CPE is no longer acting as a proxy. Therefore, the TCP/UDP packets do not need to be processed by the CPE local process. In this case, after the LAN side message arrives at the bridge (br0) device, it is forwarded directly to the PNAT0 device through the route. After the IPv6 protocol stack is converted, the downlink packet arrives at the IPv4 protocol stack and is directly routed to the br0 device. The ethx device forwards to the LAN side.

In the embodiment of the present invention, the PNAT0 device and the PREROUTINGHOOK connection point of the CPE of the network access device perform mutual conversion processing on the IPv4/IPv6 packet, and the processing flow of the data packet and the DNS packet in the TCP/UDP are in the two processes. It is consistent and will not be repeated here.

Correspondingly, with reference to FIG. 3, an embodiment of the present invention further provides a device for implementing network transition based on PNAT to IPv6, which is deployed on a network access device CPE located between a LAN side and a WAN side, and includes:

The first transmission module 100 is configured to obtain a packet;

The PNAT module 200 is configured to perform prefix network address translation on the packet.

The second transmission module 300 is configured to perform a corresponding uplink or downlink transmission by using the conversion result provided by the PNAT module 200.

When the first transmission module 100 obtains an uplink IPV4 packet, the PNAT module 200 is configured to convert the uplink IPV4 packet into an uplink IPv6 packet.

The uplink IPV4 packet is generated by the LAN side or locally.

When the first transmission module 100 acquires the downlink IPV6 packet, the PNAT module 200 is configured to convert the downlink IPV6 packet into a downlink IPv4 packet, and further configured to put the downlink IPv4 packet into IPv4 protocol stack to wait for route forwarding.

The PNAT module 200 is further configured to add a prefix network address translation PNAT rule to the PREROUTINGHOOK attachment point of the ip6tables framework, so as to convert the downlink IPV6 packet into a downlink IPv4 packet.

In this embodiment, referring to FIG. 2, the step of the network access device CPE performing prefix network address translation PNAT on the DNS packet includes (as shown by the dotted line in FIG. 2):

(3) After receiving the AAAA record message, the PNAT0 virtual device converts the source IP address and the destination IP address of the IPv4 packet into an IPv6 address by using the LIR prefix and the WKP prefix, and converts the IPv4 header into an IPv6 header, and then continues to the IPv6 protocol stack. deal with;

(5) Obtaining an AAAA response message replied by the WAN side;

In this embodiment, the process of performing a prefix network address translation PNAT on a data packet such as TCP/UDP by the host device on the LAN side (as shown by the solid line in FIG. 2) includes:

The forwarding process of data packets such as TCP/UDP is similar to the DNS packet in 1). The difference is that the CPE is no longer acting as a proxy. Therefore, the TCP/UDP packets do not need to be processed by the CPE local process. After the LAN-side packet reaches the br0 device, the packet is directly forwarded to the PNAT0 device. The downlink packet is forwarded to the IPv4 protocol stack after being translated to the IPv4 protocol stack, and then directly routed to the br0 device and then forwarded to the LAN through the ethx device. side.

In the present invention, the PNAT0 device of the network access device CPE and the PREROUTINGHOOK connection point perform mutual conversion processing on the IPv4/IPv6 packet, and the processing flow of the TCP/UDP data packet and the DNS packet are consistent in the two processes. , no longer repeat them here.

The embodiment of the present invention further provides a network access device CPE, which includes a network conversion implementation device based on PNAT to IPv6 transition as described above. Referring to FIG. 3, the device is deployed on the LAN side and the WAN side. Above the network access device CPE, including:

The first transmission module 100 is configured to obtain a packet;

For a detailed description of the application of the PNAT technology on the network access device CPE to implement the prefix network address translation, reference may be made to the above, and details are not described herein.

Referring to FIG. 4, an embodiment of the present invention further provides a system, including:

LAN side;

WAN side;

And the network access device CPE located between the LAN side and the WAN side as described above, and specifically, the network access device CPE includes a PNAT-to-IPv6-based network switching implementation device as described above, the device deployment On the network access device CPE located between the LAN side and the WAN side, referring to FIG. 3, the device for implementing network transition based on PNAT to IPv6 transition includes:

The first transmission module 100 is configured to obtain a packet;

On the LAN side, including a PC, the PC can support an IPv4 protocol stack. In the present invention, since only the network access device CPE needs to be modified, no special functional requirements are imposed on the PC.

For the network access device CPE, which is used to implement the PNAT function, the IPv4 packet provided by the LAN side, the IPv6 packet converted by the NAT64 device, the IPv6 server (Server) on the WAN side, and the IPv6 packet of the IPv6 host on the WAN side. The conversion or mapping is performed to enable seamless interaction between the WAN side or the OLT (optical line terminal) device side IPv6 message and the LAN side message.

On the WAN side, including OLT, NAT64, DNS64, etc.:

The NAT 64 performs NAT translation on the IPv6 and IPv4 packets according to the configured prefix information, so that the two networks can communicate with each other.

The DNS64 is deployed in conjunction with the NAT64 to provide a DNS ALG function. The A record corresponding to the domain name in the IPv4 network is converted into an AAAA record and forwarded to the IPv6 requesting end.

As shown in FIG. 5, it is a schematic diagram of a process of processing a DNS packet when a PC accesses an IPv4 network in the embodiment. The process is applied to a scenario where an IPV4 host device accesses IPV4 via an IPV6 network, and is now accessed by www.baidu. The com IPv4 domain name is used as an example:

Step 2a01: The IPv4 host initiates an A-record DNS request message whose domain name is www.baidu.com.

Step 2a02: The CPE parses the DNS request packet, and when it finds that it is an A record request, it converts it into an AAAA record request message, and forwards it to the DNS64 device through forwarding by the OLT, BRAS, and the like;

Step 2a03: The DNS64 device first forwards the received AAAA record request message to the DNS server to check whether an IPv6 address corresponding to the domain name exists.

Step 2a04: The IP address corresponding to the www.baidu.com domain name is an IPv4 address, and the DNS server does not include an IP address in the reply to the AAAA type request packet.

Step 2a05: After receiving the null response message of the AAAA record, the DNS64 device sends the request message of the A record again.

Step 2a06: The DNS server responds to the A record request message, and responds with a response message including the IPv4 address 220.181.112.143 of the www.baidu.com domain name;

Step 2a07: After receiving the response message of the A record, the DNS64 device converts the A record into an AAAA record according to the NAT64 prefix and forwards it to the CPE device through the BRAS, OLT, and the like;

Step 2a08: After receiving the response message of the AAAA record, the CPE device removes the NAT64 prefix and restores the AAAA record to the A record and forwards it to the LAN side PC.

As shown in FIG. 6, the flow chart of the processing of the DNS packet when the PC accesses the IPv6 network in the embodiment is shown in the embodiment. The process is applied to the scenario where the IPV4 host device accesses the IPV6 through the IPV6 network, and now accesses ipv6.google. The com IPv6 domain name is used as an example:

Step 2b01: The Pv4 host initiates an A-record DNS request message whose domain name is ipv6.google.com;

Step 2b02: The CPE parses the DNS request packet, and when it is found to be the A record request, it is converted into an AAAA record request message, and is forwarded to the DNS Server device by the OLT, BRAS, and the like;

Step 2b03: The IPv6 address corresponding to the ipv6.google.com domain name is 2a00:1450:4004:803::1011, and the DNS server replies with the response packet containing the IPv6 address, and forwards it to the CPE through the BRAS, OLT, and the like;

Step 2b04: The IPv6 address corresponding to the domain name does not contain the NAT64 prefix. After receiving the DNS response packet, the CPE maps the IPv6 address to an IPv4 address of the form similar to 1.0.0.1, and converts the AAAA record packet to the A record and forwards it to the LAN. Side PC.

With reference to FIG. 2, it shows the forwarding process of the packet in the CPE of the network access device in this embodiment, where the dotted line part is the forwarding process of the DNS packet, and the solid line part is the data packet such as TCP/UDP. The forwarding process of the text, the following focuses on the description of the two forwarding processes:

First, the LAN side HOST host obtains the IPv4 domain name process (shown in the dotted line):

(1) The HOST host on the LAN side sends an A-record DNS request packet to the DNS proxy process via a virtual device such as ethx or br0 in the CPE device.

(2) The DNS proxy process parses the request packet, and if it is the A record request packet, it is converted into an AAAA record packet, and then routed to the PNAT0 virtual device;

Among them, PNAT0 is a network virtual device deployed in a CPE device, and mainly performs translation and conversion of IPv4 to IPv6 packets. After receiving the DNS request packet from the AAAA, the PNAT0 uses the LIR prefix and the WKP prefix to translate the source IP address and the destination IP address of the IPv4 packet into an IPv6 address, and converts the IPv4 header into an IPv6 header for processing by the IPv6 protocol stack.

(3) After receiving the IPv6 packet converted by the PNAT0 device, the IPv6 protocol stack is routed to the outbound interface nbif virtual device, and finally forwarded to the WAN side through the sending function of the device;

(4) Referring to the forwarding process of the DNS message on the WAN side as shown in FIG. 4, the CPE finally obtains the AAAA type response message replied by the DNS server.

(5) In the embodiment of the present invention, a corresponding rule is added to the PREROUTINGHOOK connection point of the ip6tables framework, and the IPv6 packet with the WKP prefix as the source IP or the LIR prefix as the destination IP is converted, and the packets are restored to the corresponding IPv4 report. Text. The AAAA type IPv6 response packet is reverted to an IPv4 packet and forwarded to the IPv4 protocol stack when it passes the PREROUTINGHOOK attachment point of the IPv6 protocol stack.

(6) The DNS packet is routed to the DNS proxy process in the IPv4 protocol stack. The DNS proxy process parses the packet and converts the AAAA record into an A record. The IPv6 address corresponding to the domain name is deleted and restored to the IPv4 address.

(7) Finally, the DNS response message including the A record is forwarded to the LAN-side HOST host via the virtual device such as br0 or ethx in the IPv4 protocol stack.

Second, the LAN side HOST TCP / UDP and other data packets forwarding process (shown in the solid line):

The main focus of the embodiment of the present invention is that the PNAT0 device and the PREROUTINGHOOK connection point of the network access device CPE perform mutual conversion processing on IPv4/IPv6 packets, and the processing of TCP/UDP data packets and DNS packets in these two places. The process is consistent, so I won't go into details.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the invention, and the equivalent structure or equivalent process transformations made by the description of the invention and the drawings are directly or indirectly applied to other related The technical field is equally included in the scope of patent protection of the present invention.

Industrial applicability

Based on the foregoing technical solution provided by the embodiment of the present invention, the PNAT function is implemented on the network access device CPE to implement the transition to the IPv6, and the technical problem existing in the prior art is avoided: the dual stack technology itself also consumes the IPv4 address, which As a result, in the process of implementing the dual-stack migration scheme, the IPv4 address depletion will not be fundamentally solved, and the tunnel technology must have symmetric use of the tunnel peer device to complete the transmission of the IPv4 payload in the IPv6 network, and its application scenario Limited, the mutual access between the IPv4 host and the peer IPv6 network cannot be completed. The problem that the modification of the host device in the prior art needs to be modified for a large number of hosts and the feasibility is not high is solved.

Claims

A network switching implementation method based on PNAT to IPv6 transition is applied to a network access device CPE located between a local area network LAN side and a wide area network WAN side, and includes:

Obtain a message;

Performing a prefix network address translation PNAT on the packet, and performing a corresponding uplink or downlink transmission on the conversion result.
The method for implementing a network transition based on PNAT to IPv6 according to claim 1, wherein for the uplink IPV4 message, the prefix network address translation PNAT includes:

The uplink IPV4 packet is converted into an uplink IPv6 packet.
The method for implementing a network transition based on PNAT to IPv6 according to claim 2, wherein the uplink IPV4 message is generated by a LAN side or generated locally.
The method for implementing a network transition based on the transition from PNAT to IPv6 according to any one of claims 1-3, wherein, for the downlink IPV6 packet, the prefix network address translation PNAT includes:

Converting the downlink IPV6 packet into a downlink IPv4 packet;

The downlink IPv4 packet is placed in the IPv4 protocol stack to wait for route forwarding.
The method for implementing a network transition based on PNAT to IPv6 according to claim 4, wherein a prefix network address translation PNAT rule is added to the PREROUTINGHOOK attachment point of the ip6tables framework to convert the downlink IPV6 packet into a downlink IPv4 packet. Text.
A device for implementing a network transition device based on the transition from PNAT to IPv6, which is deployed on a network access device CPE located between a local area network LAN side and a wide area network WAN side, and includes:

a first transmission module, configured to acquire a message;

a PNAT module, configured to perform prefix network address translation on the packet;

The second transmission module is configured to perform corresponding uplink or downlink transmission by using the conversion result provided by the PNAT module.
The apparatus for implementing a network transition based on PNAT to IPv6 according to claim 6, wherein when the first transmission module acquires an uplink IPV4 packet, the PNAT module is configured to convert the uplink IPV4 packet into Upstream IPv6 packets.
The apparatus for implementing network transition based on PNAT to IPv6 according to claim 7, wherein the uplink IPV4 message is generated by a LAN side or locally generated.
The apparatus for implementing a network transition based on PNAT to IPv6 according to any one of claims 6-8, wherein when the first transmission module acquires a downlink IPV6 packet, the PNAT module is configured to set the downlink The IPV6 packet is converted into a downlink IPv4 packet, and is set to put the downlink IPv4 packet into the IPv4 protocol stack to wait for route forwarding.
The apparatus for implementing a network transition based on PNAT to IPv6 according to claim 9, wherein the PNAT module is further configured to add a prefix network address translation PNAT rule to a PREROUTINGHOOK attachment point of the ip6tables framework to implement the downlink IPV6. The packet is translated into a downlink IPv4 packet.
A network access device CPE, comprising: a network transition implementation device based on PNAT to IPv6 transition according to any one of claims 6-10.
A system comprising:

LAN side of the local area network;

WAN side of the WAN;

And a network access device CPE located between the LAN side and the WAN side according to claim 11.