Automatic determination of correct IP address for network-connected devices

Abstract

An automatic reconfiguration system for industrial networked devices. The system facilitates use of TCP/IP networks, such as Ethernet, as an alternative for industrial fieldbus or device buses by removing the need to perform significant reconfiguration of devices such as I/O modules, sensors, or transducers under field replacement situations. In one embodiment the invention uses a monitor agent to track the IP and MAC addresses of networked devices as well as port information. If a device fails, maintenance personnel make an in-field replacement of the failed device and the monitor agent automatically reassigns the correct IP address to the replacement device.

1 . A method for determining a correct logical address to assign to a target network device on a network, comprising: 
 maintaining a list of assignments of logical addresses for a plurality of networked devices, said list associating said logical addresses with a network physical address and a canonical location;    receiving a request for said correct logical address from the target network device, wherein said request includes a target network device physical address;    searching the list of assignments for a target network device physical address match, and providing the correct logical address to the target network device upon finding said target network device physical address match;    if no said target network device physical address match is found from said searching, the method further comprising:    interrogating at least one managed network switch on the network for a logical address and a port number associated with said target network device physical address and deriving a canonical location from said logical address and port number; and    searching the list of assignments for a canonical location match and providing said correct logical address upon said canonical location match.    
   
   
       2 . The method according to  claim 1 , wherein said interrogating comprises requesting said at least one managed network switch to provide said logical address and said port number based upon at least one message associated with the target network device physical address.  
   
   
       3 . The method according to  claim 1 , wherein the logical address is an Internet protocol (IP) address and the target network device physical address is a media access control (MAC) address.  
   
   
       4 . The method according to  claim 1 , wherein communications on said network are via a TCP/IP protocol.  
   
   
       5 . The method according to  claim 1 , wherein the request from the target network device conforms to a protocol from the group consisting of: Bootstrap protocol (BOOTP) and Dynamic Host Configuration Protocol (DHCP).  
   
   
       6 . The method according to  claim 1 , wherein the request to the managed switches conforms to the Simple Network Management Protocol (SNMP) protocol.  
   
   
       7 . The method according to  claim 1 , wherein said list is stored on a monitor agent, and wherein said monitor agent comprises a computing device and memory.  
   
   
       8 . The method according to  claim 1 , wherein the target network device is directly coupled to a port of the managed network switch identified by the canonical location.  
   
   
       9 . The method according to  claim 1 , wherein at least one of said plurality of network devices is coupled to a port of one or more unmanaged switches or hubs, and a single logical address for the at least one of said network devices is maintained in the list.  
   
   
       10 . The method according to  claim 1 , wherein at least one of said plurality of network devices is coupled to a port of one or more unmanaged switches or hubs, and at least one logical address for the at least one of said network devices is maintained in the list.  
   
   
       11 . The method according to  claim 1 , wherein said searching the list of assignments for a canonical location match returns more than one logical address, the method further comprises: 
 determining that there is only one not in service network device among said more than one logical address, and said correct logical address is from said one not in service network device.    
   
   
       12 . The method according to  claim 11 , wherein said determining is accomplished by transmitting a message to each said network device among said more than one logical address, and wherein a response indicates that the device is in service, and the absence of a response indicates that the device is not in service  
   
   
       13 . The method according to  claim 1 , wherein said interrogating is performed using a communications form selected from the group consisting of: Internet Control Message Protocol (ICMP), Packet Internet Groper (PING) message, multicast ARP REQUEST message, and unicast ARP REQUEST message.  
   
   
       14 . The method according to  claim 1 , further comprising periodically polling said networked devices to determine whether each of the logical addresses is currently in service.  
   
   
       15 . The method according to  claim 14 , wherein said periodic polling is selected from the group consisting of: ICMP PING, multicast ARP request, and unicast ARP request.  
   
   
       16 . A method for determining a canonical location for a plurality of networked devices, comprising: 
 maintaining a list of logical addresses for each of said plurality of networked devices on a monitor agent;    processing a network device physical address for each of said plurality of networked devices;    maintaining a list of said network device physical address for each of said plurality of networked devices on said monitor agent;    receiving a port number on a switching device for each said network device physical address;    maintaining a list of port numbers for each of said plurality of networked devices on said monitor agent; and    processing said canonical location for each of said plurality of networked devices.    
   
   
       17 . A method according to  claim 16 , wherein said monitor agent comprises a computing means and a memory means.  
   
   
       18 . A method according to  claim 16 , wherein said switching device is a managed switching device and said port number is dedicated to said networked device and is said canonical location.  
   
   
       19 . A method according to  claim 16 , wherein said switching device is an unmanaged switching device and said port number is shared among a plurality of target devices.