X370 Killer SLI/ac Ethernet Issue

In April I bought a pair of X370 Killer SLI/ac system boards, Ryzen 7 1700 CPUs, RAM, etc., and assembled computers for both wife and me.  On both of these system boards, a reboot CAN cause the built in Intel Ethernet adapter to not recognize that a cable is plugged into it (this is an intermittent problem).  I have upgraded the BIOS from whatever the original was (perhaps 2.4?) through all subsequent versions.  I have 3.1 on now.  Almost all BIOS updates were performed through the BIOS, only once did I use a USB drive.  I can get the Ethernet connection to work by either unplugging the Ethernet cable and plugging it back in after 10 seconds or two, or by running the adapter built in hardware diagnostic test.  The problem can also occur if I go into the BIOS / UEFI, and not let Windows boot up, so it appears to be a hardware problem and not a Windows driver problem.  I am using two to three meter Cat 6 cables, plugged into a Cisco / Linksys 5 port Gigabit switch, and the Intel adapters are set to auto negotiate link speed.  Has anybody else seen this problem before?  Any fix?  Our previous system boards used Realtek 8111 Gigabit adapter, and had no problems with them.

jdillipl wrote: In April I bought a pair of X370 Killer SLI/ac system boards, Ryzen 7 1700 CPUs, RAM, etc., and assembled computers for both wife and me.  On both of these system boards, a reboot CAN cause the built in Intel Ethernet adapter to not recognize that a cable is plugged into it (this is an intermittent problem).  I have upgraded the BIOS from whatever the original was (perhaps 2.4?) through all subsequent versions.  I have 3.1 on now.  Almost all BIOS updates were performed through the BIOS, only once did I use a USB drive.  I can get the Ethernet connection to work by either unplugging the Ethernet cable and plugging it back in after 10 seconds or two, or by running the adapter built in hardware diagnostic test.  The problem can also occur if I go into the BIOS / UEFI, and not let Windows boot up, so it appears to be a hardware problem and not a Windows driver problem.  I am using two to three meter Cat 6 cables, plugged into a Cisco / Linksys 5 port Gigabit switch, and the Intel adapters are set to auto negotiate link speed.  Has anybody else seen this problem before?  Any fix?  Our previous system boards used Realtek 8111 Gigabit adapter, and had no problems with them.

I have the same board with 10' of CAT 6 shielded network cable into the board connected to a simple network switch, and the switch connected via 100' of CAT 6 shielded cable to my router. The Intel network chips on this and my many other ASRock boards work flawlessly at all times. I wish everything else worked as perfectly and issue free as the Intel network chips. Of course I use the Intel network chip drivers, and cannot recall one version that had any issues. That is, except for Windows 10 breaking the Teaming option for boards with multiple network chips.

UEFI/BIOS updates have never changed anything about the functioning of the Intel network chips.

I shutdown and restart the Ryzen PC all the time, and have never lost the network connection. If you are not using the Intel network driver, that would be the place to start. It sounds like you might be using the Intel driver now. Did you ever run the cable diagnostic test in the Device Manager Properties for the Intel network adapter? I've had seemingly good cables return less than perfect test results.

Perhaps ironically, the Realtek network chips are the budget, low price option used to save money on a board. I've used them too, they were Ok, their drivers are certainly not at the level of Intel's.

Are you using crossover cables per chance?  The issue you described will normally happen if you are using the wrong cable type, to where it can't auto negotiate. 

OK, update from over the weekend testing.  My Gigabit Ethernet switch is cascaded from my wireless router, which has 4 Fast Ethernet LAN connections.  I moved all Ethernet cables to the router and removed the Gigabit switch from the environment.  Multiple reboots have been stable so far.  To me this leaves two possibilities.  Either my Gigabit switch is incompatible with the Intel NIC chip on these system boards (an admittedly inexpensive switch), or the Intel NIC chip has issues with Gigabit speed.  This week I will be getting a new Gigabit switch to test this out.  I suspect the old switch over the Intel NIC chip.

jdillipl wrote: Final update.  I bought a new Gigabit switch yesterday, and no problems with networking.  The old Gigabit switch must have an incompatibility with the Intel NIC chip on this system board.  I found the receipt for when I bought it, and it was 7 years ago, so no problems with replacing it now.

Thank you for the update. I would have hated to never know at least in general what the issue was. I suppose it is possible your old switch developed a problem, but quite a coincidence it started when you changed to a board with an Intel network interface.