Message transmission method, access node, access controller, and access system

1. A method comprising:

receiving, from an access node, a first message comprising a first identifier, wherein the first identifier comprises a tunnel identifier, a medium access control (MAC) address of the access node, or an Internet Protocol (IP) address of the access node;

obtaining, based on the first identifier, a second message comprising a line identifier corresponding to the first identifier;

sending, to a relay server, the second message;

receiving, from the relay server, a fourth message comprising the line identifier and an IP address prefix;

obtaining, based on the line identifier, a third message comprising the IP address prefix and the first identifier; and

sending, to the access node, the third message.

2. The method of claim 1 , obtaining the line identifier by encoding the first identifier.

3. The method of claim 1 , wherein the first message and the second message comprise Dynamic Host Configuration Protocol (DHCP) messages, and wherein obtaining the second message comprises adding the line identifier to the first message.

4. The method of claim 1 , wherein the first message comprises a router solicitation (RS) message, wherein the second message comprises an authentication, authorization, and accounting (AAA) message, wherein obtaining the second message comprises generating the AAA message according to the RS message and the line identifier, and wherein the first message comprises the line identifier.

5. The method of claim 1 , further comprising obtaining the line identifier by encoding the line identifier.

6. The method of claim 1 , wherein the fourth message comprises a first Dynamic Host Configuration Protocol (DHCP) message, and wherein the method further comprises:

obtaining, a second DHCP message based on the first DHCP message, wherein the second DHCP message does not comprise the line identifier; and

further obtaining the third message based on the second DHCP message and the first identifier, wherein the third message comprises the second DHCP message.

7. The method of claim 1 , wherein the fourth message comprises an authentication, authorization, and accounting (AAA) message, and wherein the method further comprises:

obtaining a router advertisement (RA) message according to the AAA message and the IP address prefix, wherein the RA message does not comprise the line identifier; and

further obtaining the third message based on the first identifier and the RA message, wherein the third message comprises the RA message.

8. The method of claim 1 , wherein the tunnel identifier is of the access node.

9. The method of claim 1 , wherein the first identifier further comprises a physical port number that is of the access node and that is a preset value.

10. The method of claim 1 , wherein the first identifier further comprises a logical port number.

11. The method of claim 1 , wherein the line identifier further comprises a virtual local area network identifier (VID) of the access node, a virtual path identifier (VPI) of the access node, or a virtual channel identifier (VCI) of the access node.

12. The method of claim 1 , wherein the line identifier comprises a physical identifier of the access node, and wherein the physical identifier comprises a cabinet chassis number, a rack number, a frame number, a slot number, a sub-slot number, or a port number.

13. The method of claim 1 , wherein the IP address prefix is not a full IP address.

14. An access controller comprising:

a non-transitory computer-readable storage medium configured to store programming instructions; and

a processor coupled to the non-transitory computer-readable storage medium and configured to execute the programming instructions to cause the access controller to:

receive, from an access node, a first message comprising a first identifier, wherein the first identifier comprises a tunnel identifier, a medium access control (MAC) address of the access node, or an Internet Protocol (IP) address of the access node;

obtain, based on the first identifier, a second message comprising a line identifier corresponding to the first identifier;

send, to a relay server, the second message;

receive, from the relay server, a fourth message comprising the line identifier and an IP address prefix;

obtain, based on the line identifier, a third message comprising the IP address prefix and the first identifier; and

send, to the access node, the third message.

15. The access controller of claim 14 , wherein the processor is further configured to execute the programming instructions to cause the access controller to obtain the line identifier by encoding the first identifier.

16. The access controller of claim 14 , wherein the first message and the second message comprise Dynamic Host Configuration Protocol (DHCP) messages, and wherein the processor is further configured to execute the programming instructions to cause the access controller to obtain the second message by adding the line identifier to the first message.

17. The access controller of claim 14 , wherein the first message comprises a router solicitation (RS) message, wherein the second message comprises an authentication, authorization, and accounting (AAA) message, wherein the processor is further configured to execute the programming instructions to cause the access controller to obtain the second message by generating the AAA message according to the RS message and the line identifier, and wherein the first message comprises the line identifier.

18. The access controller of claim 14 , wherein the processor is further configured to execute the programming instructions to cause the access controller to obtain the line identifier by encoding the line identifier.

19. The access controller of claim 14 , wherein the fourth message comprises a first Dynamic Host Configuration Protocol (DHCP) message, and wherein the processor is further configured to execute the programming instructions to cause the access controller to:

obtain a second DHCP message based on the first DHCP message, wherein the second DHCP message does not comprise the line identifier; and

obtain the third message based on the second DHCP message and the first identifier, wherein the third message comprises the second DHCP message.

20. The access controller of claim 14 , wherein the fourth message comprises an authentication, authorization, and accounting (AAA) message, and wherein the processor is further configured to execute the programming instructions to cause the access controller to:

obtain a router advertisement (RA) message according to the AAA message and the IP address prefix, wherein the RA message does not comprise the line identifier; and

obtain the third message according to the first identifier and the RA message, wherein the third message comprises the RA message.

21. An access apparatus comprising:

a non-transitory computer-readable storage medium configured to store programming instructions; and

a processor coupled to the non-transitory computer-readable storage medium and configured to execute the programming instructions to cause the access apparatus to:

receive, from a user, a second message comprising a Dynamic Host Configuration Protocol (DHCP) message or a router solicitation (RS) message;

obtain a first message based on the second message, wherein the first message comprises the second message and a first identifier corresponding to a line identifier, whereinand wherein the first identifier comprises a tunnel identifier, a medium access control (MAC) address of an access node, or an Internet Protocol (IP) address of the access node;

send, to an access controller, the first message;

receive, from the access controller, a third message comprising the first identifier and a fourth message, wherein the fourth message comprises an IP address prefix; and

send, to the user based on the line identifier, the fourth message.

22. The access apparatus of claim 21 , wherein the processor is further configured to execute the programming instructions to cause the access apparatus to obtain the line identifier by encoding the first identifier.

23. The access apparatus of claim 21 , wherein the processor is further configured to execute the programming instructions to cause the access apparatus to obtain the line identifier by encoding the first identifier.

24. The access apparatus of claim 21 , wherein the IP address prefix is not a full IP address.