Patent ID: 6728767
Filing Date: 2004-04-27
Classification: H04L

Abstract:
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.