Method of resolving duplicate MAC addresses, network device management system, server, and information device
MAC addresses of information devices on a network are collected using a broadcast frame or multicast frame of Ethernet®. If duplicate MAC addresses are detected, an Ethernet® frame, including a device identifier of information device and a MAC address to be set, is sent by broadcast transmission or multicast transmission. The information devices receiving this Ethernet® frame compare the above device identifier with their own device identifiers. If they match, the MAC address is changed to that designated. Duplicate MAC addresses are thus resolved, enabling correct Ethernet® communications.
1. A method of resolving duplicate MAC addresses in a network configured with a server managing MAC addresses and a plurality of information devices, wherein
the server distributes a MAC request frame that requests a MAC address of each of the plurality of information devices on the network,
collects a MAC information frame returned from each of the plurality of information devices, the MAC information frame including a MAC address and a device identifier of a transmitting information device; and
if duplication of the MAC addresses in the collected MAC information frames is detected, the server distributes a MAC setting frame including the device identifiers of information devices having duplicate MAC addresses and new MAC addresses to the network so as to change MAC addresses of the information devices having the duplicate MAC addresses to the new MAC addresses.
2. The method of resolving duplicate MAC addresses of claim 1 , wherein if three or more information devices have the same MAC address, the MAC setting frame includes a plurality of sets of information of the device identifier and new MAC address of the information devices having the duplicate MAC addresses.
3. The method of resolving duplicate MAC addresses of claim 1 , wherein
the server generates a list that correlates the device identifier and the MAC address of each of the information devices on the network based on the MAC information frames collected, and
a MAC address not present in the list is set as the new MAC address.
4. A method of resolving MAC addresses in a network configured with a server managing MAC addresses and a plurality of information devices,
wherein
the server distributes a MAC request frame that requests a MAC address of each of the plurality of information devices on the network,
collects a MAC information frame returned from each of the plurality of information devices, the MAC information frame including a MAC address and a device identifier of a transmitting information device, and
if duplication of the MAC addresses in the collected MAC information frames is detected, the server distributes a MAC setting frame including the device identifiers of information devices having duplicate MAC addresses and new MAC addresses to the network so as to change MAC addresses of information devices having the duplicate MAC addresses to the new MAC addresses,
wherein
the server generates a list that correlates the device identifier and the MAC address of each of the information devices on the network based on the MAC information frames collected, and
a MAC address not present in the list is set as the new MAC address, and
wherein
whether or not a MAC address of the server is unique on the network is determined based on the list, and
a determination result concerning whether or not the MAC address of the server is unique on the network is sent to the information devices so that the information devices designate a destination address of the MAC information frame as the MAC address of the server if the MAC address of the server is unique.
5. The method of resolving duplicate MAC addresses of claim 1 , wherein
the device identifier of each of the information devices includes at least one of a serial number of the information device, information that specifies a type of information device, a part number, and a manufacturing date code.
6. The method of resolving duplicate MAC addresses of claim 1 , wherein
the server distributes the MAC request frame by one of multicast transmission or broadcast transmission.
7. A network device management system, in which a plurality of information devices and a server managing a MAC address of each of the information devices are connected to a network, for resolving duplicate MAC addresses of the information devices on the network,
the server comprising:
a MAC request frame generator for requesting the MAC address of each of the plurality of information devices;
a received frame analyzer for extracting MAC information and a device identifier from a MAC information frame received from each of the information devices;
a MAC information and device identifier retention unit for retaining a set of the MAC information and the device identifier;
a duplication detector for searching information retained in the MAC information and device identifier retention unit, and detecting duplicate MAC information; and
a MAC setting frame generator for generating a MAC setting frame based on a result detected by the duplication detector; and
the information device comprising:
a MAC information and device identifier retention unit for retaining a set of its own MAC information and a device identifier;
a received frame analyzer for extracting the MAC information and the device identifier in the MAC setting frame received from the server;
a MAC information update unit for comparing the device identifier obtained from the received frame analyzer and the device identifier obtained from the MAC information and device identifier retention unit, and updating its own MAC information with the MAC information obtained from the MAC information analyzer if the device identifiers match; and
a MAC information frame generator for obtaining the set of its own MAC information and device identifier from the MAC information and device identifier retention unit, and generating a MAC information frame.
8. A server connected to a plurality of information devices in a network, and manages MAC addresses of the information devices, the server comprising:
a MAC request frame generator for requesting a MAC address of each of the information devices;
a received frame analyzer for extracting MAC information and a device identifier in a MAC information frame received from each of the information devices;
a MAC information and device identifier retention unit for retaining a set of the MAC information and the device identifier;
a duplication detector for searching information retained in the MAC information and device identifier retention unit, and detecting duplicate MAC information; and
a MAC setting frame generator for generating a MAC setting frame based on a result detected by the duplication detector.
9. An information device connected to a server that manages MAC address of devices on a network, the information device comprising:
a MAC information and device identifier retention unit for retaining a set of its own MAC information and device identifier;
a received frame analyzer for extracting MAC information and a device identifier in a MAC setting frame received from the server;
a MAC information update unit for comparing the device identifier obtained from the received frame analyzer and the device identifier obtained from the MAC information and device identifier retention unit, and updating its own MAC information with MAC information obtained from the MAC information analyzer if the device identifiers match; and
a MAC information frame generator for obtaining its own MAC information and device identifier from the MAC information and device identifier retention unit, and generating a MAC information frame.
10. The method of resolving duplicate MAC addresses of claim 1 , wherein
the server distributes the MAC setting frame by one of multicast transmission or broadcast transmission.
11. The network device management system of claim 7 , wherein
the device identifier of each of the information devices includes at least one of a serial number of the information device, information that specifies a type of information device, a part number, and a manufacturing date code.
12. The server of claim 8 , wherein
the device identifier of each of the information devices includes at least one of a serial number of the information device, information that specifies a type of information device, a part number, and a manufacturing date code.
13. The information device of claim 9 , wherein
the device identifier includes at least one of a serial number of the information device, information that specifies a type of information device, a part number, and a manufacturing date code.