My GA-Z170X-Gaming 7 crashes my home LAN if it boots to the BIOS and stays there for longer than 15 seconds. I have no idea how/why this happens.
Our LAN is set up with both wired and wireless connections, approximately 27 devices in total. There are zero issues when all devices are online and active. When we experienced a power outage three weeks ago my computer booted into the BIOS (even though I had it set to not reboot on AC loss) with an error of incorrect OC settings. I was away at work when this happened and my roommates called me because they couldn't get the network back up. After an hour of troubleshooting I asked them for a second time if my computer was up. (They said 'no' the first time because they assumed 'up' meant booted to the OS.) After unplugging my computer from the network everything worked immediately.
This weekend I was having issues with the computer locking up after booting into Windows and logging it. I'm assuming this was a Skylake or Windows issue because even without OC settings it would still freeze but using memtest86+ and several other Linux distros worked just fine. As I was combing through the settings in the BIOS several times over the weekend the network would once again grind to a halt.
I ran a few tests with my motherboard with several different network topologies and equipment and could reproduce the issue every time. After 15 seconds of being in the BIOS, all client devices were unable to find the gateway because a huge broadcast storm would occur. For those of you unfamiliar with the networking term, a 'broadcast storm' occurs if either:
- a device endlessly sends out broadcast packets until all bandwidth is consumed
- a loop in the network connections exists
The second is not possible because when I plugged in the motherboard directly to the router and had only one other device connected, the issue persisted. What I find to be peculiar is that using Wireshark to capture the packets does not reveal
anything to be coming from the motherboard, even if I set up a direct (host-to-host) connection with the laptop that was being used. But every time that the network went down, unplugging the motherboard from the network ceased the broadcast storm and immediately resolved the issue. What is the motherboard doing on the network that is causing this issue?
