DBU oddity

The system has an exit point program installed to associate an IP adress with a specific device. My involvement is to maintain the datafile.

When networking was started, there weren't a lot of devices, and the addresses were assigned to 172.16.x.x. The corporate office wants all the hospitals in the system to convert to a 10.x.x.x addressing method. Since all the locations use NAT to connect to the private network and then through the corporate office to the outside world, that doesn't make sense to me. Is there any rationale for changing addressing behind a NAT firewall?

The above is to explain my second question. I was told that an IP address for a device needed to be changed from 172.16.x.x to 10.0.x.x - I can't recall the exact addresses.

The file used for device assignment is keyed by IP address.

Using DBU, I found the old IP address and updated it to the new one. Except that it didn't update. I had seen this before and wondered about it. This IP address change was needed rather quickly, so I tried SQL, a simple UPDATE. That worked.

Is there anything that would explain why DBU would act like it changed the key field, but didn't - after at least two attempts, but SQL did, immediately? Only a guess, but is an object lock involved.

John McKee