Ethernet Security Certificate Error (WiFi works fine)

[BillG66]

Some of you may have seen my desperate posts where I was pulling my hair out because I was getting security certificate errors on every website. It's been a recurring theme on my Hack. In the past, I've fixed the problem various ways... flashing the BIOS, doing a clean install of the OS, restoring the entire system from my clone drive... well, today I came home to find that the machine (after a successful upgrade to High Sierra) was once again returning security certificate errors on every website. So, on a lark, I restarted the machine with the ethernet cable unplugged, and only the WiFi on. All sites are loading perfectly. Plugged the cable back up and, in a couple of clicks, the security issue was back. Note that this is only my Gigabyte Hackintosh. All other machines in the house on hard-wired ethernet are working fine, including two other Dell Optiplex 780 Hackintoshes. Is there anything in the information I have provided (or any logs I could provide) that might help me determine why a hard-wired ethernet connection would specifically (and repeatedly) cause this error on my Gigabyte Z170N Gaming 5-based Hackintosh?

 

[BillG66]

Figured it out. For some reason, using DHCP in Network preferences assigned an incorrect router address. Switching to full manual enabled me to enter the correct router IP. So, I’ll just reserve the static IP on my AirPort Extreme, and hopefully never encounter this problem again. I wish I knew why DHCP was assigning the wrong router IP... but at least I figured out how to fix it.