Network setup: The network consists of a desktop and a laptop. The desktop connects to the 825 via GigE and the 825 is connected to a cable modem. Internet performance on the wired connection is solid & consistent at 15Mbps (as expected). The desktop has a 1 TB USB external HD plugged in and network shared. Internet connectivity for the laptop works great – Windows Updates, web surfing, etc. Transferring small files (5-10) MB works fine.
Problem: Attempting to transfer files larger than 50-100MB or groups of files that add up to that size or greater, between the laptop and desktop whether they originate on the external HD or either machine results in a complete loss of all networks for all machines. Internet connectivity is dead and none of the machines can see each other. Windows 7 network troubleshooter always shows the error as “The connection between your access point, router, or cable modem and the Internet is broken. The default gateway is not available”. The problem is then resolved by the troubleshooter and connectivity restored – until I try a large transfer again. Rinse, repeat.
Currently the desktop is running Windows 7 64 bit and the laptop Windows 7 32 bit. Prior to completely rebuilding both of these machines (from scratch, no upgrades), the desktop was running Windows XP and the laptop ran Windows Vista and suffered from this same networking issue. The 825 firmware is up-to-date.
I contacted Dlink support which suggested it could be wireless phone interference on the 2.4 band but the recommendations I received to hard-code the channels resulted in a complete loss of network connectivity all of the time, hence the modem is back at factory defaults. Any help or suggestions would be greatly appreciated.