|First, try recycling the power on your router. Power it down for about 10 seconds then bring it back up. Do you get a proper IP from DHCP now?|
If not try upgrading the firmware on the router. If that doesn't fix it, or the router has the latest firmware you can then try resetting the unit to factory defaults and reconfigure it.
If that doesn't fix the issue, you may need to replace the router.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.