conflicting ip addresses

for some reason every once and awhile one of the computers on my network will lose its connection. It says there is another computer on this network with the same ip. everything is dynamic and assigned on the fly. I dont understand why its happening. its like the whole network plays nice for months then all of a sudden it keeps assigning more then 1 pc the same ip.

can anyone tell me why this is happening or how i can make sure it wont keep happening

 

Check your DHCP lease time and make sure it's not too long.

 

DHCP is set to 1 day (0) . what should it be set to

 

It's all right that way.
Can you set up IPs by MAC addresses? It's not static IP- it's DHCP but the same MAC address (computer) always gets the same IP and no other computer can get this IP. That would solve the problem however this feature is rarely available in routers for some reason.
Other than that try updating firmware on the router- I've seen DHCP bugs been corrected in third or fourth firmware edition, so apparently DHCP seems to be too complicated for some companies

 

Setting up DHCP reservations seems like an ok Idea I suppose. Updating the Firmware would be a valid choice. I would take more of a standard approach and just bring the router back to default settings and verify the results.

 

If EVERY system is set dynamic (double check), then someone is introducing a system with static IP onto the network.
If you just want to fix it, set a small dynamic IP range, and put the known systems outside of that range.

 

ok. first I will update the firmware then I willl check and see if any of them have a static ip. then I will give it a few days and look for results.

resetting all the settings in the router might be something I will try if all else fails.

 

If you use a small range of IP address or distribute a range of IP address rather then I am pretty sure it would affect the NAT settings.

 

also look into whether or not your 'router' can issue IP addys with a DHCP reservation table.

 

What brand router do you have. Most of Netgear's SMB router supports reserved IP's. I use it exclusively, makes it easier finding things. I had this happen to me on what was suppose to be a secured system. It was traced down to user in another building changing his setup to Static IP. Which was against policy, it did not go well for him. If on a larger system with smart switches you should be able to locate the culprit.

Another way to find out who has it is to setup a firewall rule which will kill access to that IP, then they may call for help. At the least he will change it to get access. You already have his MAC address from the DHCP log, so you can make life hard on him.

You do have enough IP's (range) set for the DHCP server so no one gets bumps?????

 

its a linksys. i think i tracked down the problem. it might have been a static ip that was in my xbox 360. the xbox was powered off though. so im still looking into it.