Router changes IP address

My D-Link DIR-615 changes IP addresses every few minutes, such that I have internet access four out of every five minutes or so. The problem is, when it does so, it crashes my VPN link to my workplace. (that's how I know it was an IP Address change. My VPN software told me. I thought it was just rebooting for no reason)

Is there any way I can tell it not to do that?

Thanks

 

External wan ip address changes? That sounds like an issue with the isp, but you can always try updating the router firmware or reseting it to factory defaults to troubleshoot your end.

 

Thanks. I'll try that the next time I plug it in.