Duplicate IP Address Prevents Machine Startup

Event Year: 1996 Reliability: Likely But Unconfirmed
Country: Canada
Industry Type: Pulp and Paper

The mill had upgraded the profile controller on the #1 Paper Machine to a control system that used Ethernet and TCP/IP to communicate between the scanners and the main controller.  It was also connected to the main mill network through a bridge so that profile information could be accessed by business applications.  Some time after the installation, a network printer in another area of the mill was accidentally given the same IP address as the controller.  Initially this did not cause difficulties, but shortly after a routine maintenance shutdown, the scanners started directing their data to the printer rather than to the controller.


The paper machine could not be started for over six hours.

Action Description: Installed VLANs and seperate subnets between business and process networks