[acropolite (Phil)]

Bojan, address conflicts can be caused by several factors including cascaded data switches, poorly behaved smartphones and tablets, duplicated DHCP servers, and static assignments that conflict with the dynamically assigned IO addresses allocated by your router. I see them all too often in my day to day work.

Check to see if you have any devices with static assignments, if you need static assignments the best way is to put an entry in the DHCP table of your router and set the device to get that IP via DHCP.

One common problem I’ve seen is the use of old routers as Wireless Access points without turning off the DHCP in the second device.

I’ve lost count of the times I’ve resolved issues reported as cabling problems where sloppy IT contractors have introduces IP addressing problems.

As I said before, the best advice is to reserve all addresses in the DCHP table of your router. Unfortunately some routers supplied by the biggest ISP (Telstra) have a very limited range of reservation entries available.