| 摘要 |
A system and method for determining a MAC layer address of a network interface on a remote device, based on an IP address associated with the same network interface on the remote device. The disclosed system identifies an internetworking device, for example a router, that is attached to the remote subnet to which the network interface of the remote device is attached. The system identifies the network interface of the router that is attached to the remote subnet, and obtains the MAC address of that network interface from an address resolution protocol (ARP) cache associated with it. The system transmits a series of request packets having an IP destination address equal to the provided IP address of the remote device, each including a time to live value, indicating a maximum number of network hops over which each particular packet may be forwarded. The time to live values of the request packets result in each successive request packet being forwarded one hop further along the path to the remote device. The internetworking devices along the route to the remote device each receive one request packet that cannot be forwarded because the time to live value has been decremented to zero. As a result, each internetworking device along the route returns a reply packet to the requesting device indicating its IP address.
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