Remote identification of client and DNS proxy IP addresses

• US 6,728,767 B1
• Filed: 08/18/2000
• Issued: 04/27/2004
• Est. Priority Date: 08/18/2000
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Lu, Gang, Day, Mark, Liskov, Barbara, OʼToole, James
• Primary Examiner(s): Dinh, Dung C.
• Assistant Examiner(s): EDELMAN, BRADLEY E
• Application Number:
  US09/642,143
• Time in Patent Office: 1,348 Days
• Field of Search: 709/223, 709/224, 709/245
• US Class Current: 709/223
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

A network operator identifies an address of a network element used by a particular client to obtain IP addresses. The client sends a test message to a test URL which includes a unique host name unknown to the client or network element. The network element accesses an authoritative server, which records the IP address of the requesting network element and resolves the host name in the test URL to a test IP address. The server records an IP address of the client when the client subsequently sends a message directly to the test IP address. In an alternative embodiment, another network node generates a redirect command, which incorporates the client IP address in a test URL, to allow for single-message determination of the network element and client IP addresses by the authoritative server. In both embodiments, user unique test URLs may be generated to allow the network operator to assist many users.

Claims

1. A method for identifying an address of a network element that a particular client uses to obtain IP addresses, comprising:

causing the client to send a test message destined for a test URL to a network element, the test URL including a host name at least in part distinguishable from host names in non-test URLs according to a predetermined uniqueness and not known to the client or network element but for which a test server is known to be authoritative, the network element responsively accessing the test server; and

at the test server, recognizing the predetermined uniqueness in the host name of the test URL received in a request from the network element to resolve the host name in the test URL to an IP address, and responsively (i) distinguishing the request from requests including non-test URLs, (ii) identifying the address of the network element used by the client to obtain the IP address, and (iii) registering the address of the network element making the request.

2. The method according to claim 1 wherein registering comprises logging the network element IP address.

3. The method according to claim 1 wherein the test message includes a code in the host name of the test URL to identify the test message to the server.

4. The method according to claim 1 further comprising, at the test server, (i) handing back a test IP address for the client and (ii) recording an IP address of the client when the client subsequently sends a message directly to the test IP address.

5. The method according to claim 4 wherein the test message comprises a code in the host name of the test URL to identify the test message to the server.

6. The method according to claim 1 wherein the client is caused to send the test message in response to a non-test server sending a redirect test message to the client, the redirect test message redirecting the client to the test URL.

7. The method according to claim 6 wherein the redirect test message comprises the client IP address in the host name of the redirect test message.

8. The method according to claim 7 further comprising causing the client to send a preliminary test message to the non-test server which results in the non-test server sending the redirect test message, wherein the redirect test message includes the client IP address from the preliminary test message.

9. The method according to claim 7 further comprising encoding the client IP address in the host name of the test URL.

10. The method according to claim 1 wherein the test URL is unique.

11. A system for identifying an address of a network element that a particular client uses to obtain IP addresses, comprising:

a client caused to send a message destined for a test URL to a network element, the test URL including a host name at least in part distinguishable from host names in non-test URLs according to a predetermined uniqueness and not known to the client or network element, the network element responsively accessing an authoritative server; and

a server that (i) is the authoritative server for the host name in the test URL, (ii) recognizes the predetermined uniqueness in the host name of the test URL in a request from the network element to resolve the host name of the test URL to a test IP address, and (iii) responsively (a) distinguishes the request from requests including non-test URLs, (b) identifies the address of the network element making the request, and (c) registers the address of the network element making the request.

12. The system according to claim 11 wherein the server comprises a log for storing the network element IP address.

13. The method according to claim 11 wherein the test message includes a code in the host name of the test URL to identify the test message to the server.

14. The system according to claim 11 wherein the server (i) hands back the test IP address for the client and (ii) records an IP address of the client when the client subsequently sends a message directly to the test IP address.

15. The system according to claim 14 wherein the test message comprises a code in the host name of the test URL to identify the test message to the server.

16. The system according to claim 11 wherein the client is caused to send the test message in response to a non-test server sending a redirect test message to the client, the redirect test message redirecting the client to the test URL.

17. The system according to claim 16 wherein the redirect test message comprises the client IP address in the host name of the redirect test message.

18. The system according to claim 17 wherein the client sends a preliminary test message to the non-test server which results in the non-test server sending the redirect test message, wherein the redirect test message includes the client IP address from the preliminary test message.

19. The system according to claim 17 further comprising encoding the client IP address in the host name of the test URL.

20. The system according to claim 11 wherein the test URL is unique.

21. An apparatus for identifying an address of a network element that a particular client uses to obtain IP addresses, comprising:

an interface coupled to a network to receive client messages, and

a processor coupled to the interface, the processor executing a set of computer program instructions, the computer program instructions;

receiving a request from a network element in response to the network element receiving a test message destined for a test URL from a client, the test URL including a host name at least in part distinguishable from host names in non-test URLs according to a predetermined uniqueness and not known to the client or network element but for which the apparatus is known to be authoritative; and

recognizing the predetermined uniqueness in the host name of the test URL in the request from the network element to resolve the host name to an IP address and responsively (i) distinguishing the request from requests including non-test URLs, (ii) identifying the address of the network element used by the client to obtain the IP address, and (iii) registering the network element making the request.

22. The apparatus according to claim 21 further comprising memory coupled to the processor for the processor to log the network element IP address.

23. The apparatus according to claim 21 wherein the test message includes a code in the host name of the test URL to identify the test message to the server.

24. The apparatus according to claim 21 wherein the executable instructions further include instructions to (i) hand back a test IP address for the client and (ii) record an IP address of the client when the client subsequently sends a message directly to the test IP address.

25. The apparatus according to claim 24 wherein the test message comprises a code in the host name of the test URL to identify the test message to the server.

26. The apparatus according to claim 21 wherein the instructions further comprise instructions to cause the client to send the test message in response to a non-test server sending a redirect test message to the client, the redirect test message redirecting the client to the test URL.

27. The apparatus according to claim 26 wherein the redirect test message comprises the client IP address in the host name of the redirect test message.

28. The apparatus according to claim 27 wherein the instructions further comprise instructions to cause the client to send a preliminary test message to the non-test server which results in the non-test server sending the redirect test messages, wherein the redirect test message includes the client IP address from the preliminary test message.

29. The apparatus according to claim 27 further comprising instructions to decode the client IP address from the host name of the test URL.

30. The apparatus according to claim 21 wherein the test URL is unique.

31. In a server, a method for identifying an address of a network element that a particular client uses to obtain IP addresses, comprising:

receiving a request from a network element in response to the network element receiving a test message destined for a test URL from a client, the test URL including a host name at least in part distinguishable from host names in non-test URLs according to a predetermined uniqueness and not known to the client or network element but for which the server is known to be authoritative; and

recognizing the predetermined uniqueness in the host name in the test URL received in a request from the network element to resolve the host name to an IP address and responsively (i) distinguishing the request from requests including non-test URLs, (ii) identifying the address of the network element used by the client to obtain the IP address, and (iii) registering the address of the network element making the request.

32. The method according to claim 31 further comprising logging the network element IP address.

33. The method according to claim 31 wherein the test message includes a code in a host name of the test URL to identify the test message to the server.

34. The method according to claim 31 further including, at the server, (i) handing back a test IP address for the client and (ii) recording an IP address of the client when the client subsequently sends a message directly to the test IP address.

35. The method according to claim 34 wherein the test message comprises a code in the host name of the test URL to identify the test message to the server.

36. The method according to claim 31 further comprising causing the client to send the test message in response to a non-test server sending a redirect test message to the client, the redirect test message redirecting the client to the test URL.

37. The method according to claim 36 wherein the redirect test message comprises the client IP address in the host name of the redirect test message.

38. The method according to claim 37 further comprising causing the client to send a preliminary test message to the non-test server which results in the non-test server sending the redirect test message, wherein the redirect test message includes the client IP address from the preliminary test message.

39. The method according to claim 37 further comprising decoding the client IP address from the host name of the test URL.

40. The method according to claim 31 wherein the test URL is unique.

41. A computer program product comprising:

a computer usable medium for storing data; and

a set of computer program instructions embodied on the computer useable medium, including instructions to;

receive a request from a network element in response to the network element receiving a test message destined for a test URL from a client, the test URL including a host name at least in part distinguishable from host names in non-test URLs according to a predetermined uniqueness and not known to the client or network element but for which a server executing the computer program instructions is known to be authoritative; and

recognize the predetermined uniqueness in the host name in the test URL received in the request from the network element to resolve the host name to an IP address and responsively (i) distinguishing the request from requests including non-test URLs, (ii) identifying the address of the network element used by the client to obtain the IP address, and (iii) registering the address of the network element making the request.

42. The computer program product according to claim 41 further comprising instructions to log the network element IP address.

43. The computer program product according to claim 41 wherein the test message comprises a code in the host name of the URL to identify the test message to the server.

44. The computer program product according to claim 41 further comprising instructions to (i) hand back a test IP address for the client and (ii) recording record an IP address of the client when the client subsequently sends a message directly to the test IP address.

45. The computer program product according to claim 44 wherein the test message comprises a code in the host name of the test URL to identify the test message to the server.

46. The computer program product according to claim 41 wherein the instructions further comprise instructions to cause the client to send the test message in response to a non-test server sending a redirect test message to the client, the redirect test message redirecting the client to the test URL.

47. The computer program product according to claim 46 wherein the redirect test message comprises the client IP address in the host name of the redirect test message.

48. The computer program product according to claim 47 wherein the instructions further comprise instructions to cause the client to send a preliminary test message to the non-test server which results in the non-test server sending the redirect test message, wherein the redirect test message includes the client IP address from the preliminary test message.

49. The computer program product according to claim 47 further comprising instructions to decode the client IP address from the host name of the test URL.

50. The computer program product according to claim 41 wherein the test URL is unique.

51. A method for assisting to identify an address of a network element that a particular client uses to obtain IP addresses, comprising:

receiving a message from a client;

parsing the message for an IP address of the client and encoding the client IP address into a host name for a test URL, the test URL including the host name not known to the client or network element used by the client but for which a test server is authoritative; and

returning the test URL to the client in a redirect test message, the redirect test message causing the client to send a non-redirect test message to the network element to make a request of the test server to resolve the host name in the test URL to a test IP address.

52. An apparatus for identifying an address of a network element that a particular client uses to obtain IP addresses, comprising:

means for receiving a message from a client;

means for parsing the message for an IP address of the client and encoding the client IP address into a host name for a test URL, the test URL including the host name not known to the client or network element used by the client but for which a test server is authoritative; and

means for forwarding the test URL back for the client in a redirect test message, the redirect test message causing the client to send a non-redirect test message to the network element to make a request of the server to resolve the host name in the test URL to a test IP address.

53. A communication signal on a carrier wave, the communication signal for identifying an address of a network element that a particular client uses to obtain IP addresses, and the communication signal adapted to being passed between the client and the network element, the signal including a test URL comprising a host name, at least in part distinguishable from host names in non-test URLs according to a predetermined uniqueness and not known to the client or network element but for which a test server is known to be authoritative, the signal causing the network element to resolve the host name in the test URL by accessing the test server that (a) recognizes the predetermined uniqueness in the host name of the test URL received in a request from the network element to resolve the host name in the test URL to an IP address, and (b) responsively (i) distinguishes the request from requests including non-test URLs, (ii) identifies the address of the network element used by the client to obtain the IP address, and (iii) registers the address of the network element making the request.

54. The signal according to claim 53 wherein the host name of the test URL comprises an encoded IP address of the client.

55. The signal according to claim 53 wherein the test URL is unique.