Method and apparatus for detecting a router that improperly responds to ARP requests
AssigneeApple Inc.
InventorsStuart Cheshire, Joshua Graessley
Life of this patent
Estimating the term…
Abstract
One embodiment of the present invention provides a system that detects a non-compliant router that incorrectly responds to all address-resolution-protocol (ARP) requests, including ARP requests for link-local IP addresses. This is accomplished by sending an ARP request asking for an Ethernet address associated with a link-local IP address, wherein the link-local IP address is a reserved link-local IP address, which should not be assigned to any device. If a response is received to the ARP request, the system determines that the response was sent by a non-compliant router that incorrectly responds to all ARP requests, including ARP requests for link-local IP addresses.
Claims26
A method for detecting a device that incorrectly responds to address-resolution-protocol (ARP) requests, such as a device that incorrectly responds to ARP requests for link-local IP addresses that it has not properly claimed for its own legitimate use, comprising:
- sending an ARP request asking for an Ethernet address associated with a IP address, wherein the IP address is a reserved IP address, which should not be assigned to any device;
- and
- if a response is received to the ARP request, determining that the response was sent by a device that incorrectly responds to ARP requests, including ARP requests for reserved IP addresses.
A computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for detecting a device that incorrectly responds to address-resolution-protocol (ARP) requests, such as a device that incorrectly responds to ARP requests for link-local IP addresses that it has not properly claimed for its own legitimate use, the method comprising:
- sending an ARP request asking for an Ethernet address associated with a IP address, wherein the IP address is a reserved IP address, which should not be assigned to any device;
- and
- if a response is received to the ARP request, determining that the response was sent by a device that incorrectly responds to ARP requests, including ARP requests for reserved IP addresses.
An apparatus that detects a device that incorrectly responds to address-resolution-protocol (ARP) requests, such as a device that incorrectly responds to ARP requests for link-local IP addresses that it has not properly claimed for its own legitimate use, comprising:
- a sending mechanism configured to sending an ARP request asking for an Ethernet address associated with a IP address, wherein the IP address is a reserved IP address, which should not be assigned to any device;
- and
- a detection mechanism, wherein if a response is received to the ARP request, the detection mechanism is configured to determine that the response was sent by a device that incorrectly responds to ARP requests, including ARP requests for reserved IP addresses.
A method for detecting a device that improperly responds to multicast and/or broadcast requests, comprising:
- transmitting a multicast or broadcast request to a plurality of recipients, wherein the request is structured so that the request should not be responded to;
- and
- if a response is received to the request, determining that the response was sent by a device that improperly responds to such requests.
A method for detecting a device that improperly responds to requests, comprising:
- transmitting a request, wherein the request is structured so that the request should not be responded to;
- and
- if a response is received to the request, determining that a device which generated the response improperly responds to such requests.
Dependencies are inferred from the claim text.