Hello, As per headline, this is a factory install on a Linksys 1900AC V1.
THE SETUP
I have a ISP fiber modem it has no user functionality other than a power switch. I also removed my ISP Netis WF2780 router which works great, but, I want the power and functionality of LEDE on Linksys. I want the Linksys to be my primary router.
I want to retain: Fiber Modem -» Linksys LEDE Router -» my lan devices.
MY GOAL
I want to have my lan clients protected by router based VPN.
I want to eventually add smart home functionality in the future.
The 2 digital TV's I have -one is smart, the other just an early model internet friendly TV- are RJ45 cabled but WiFi/Google Home usually works well enough.
I want to " jailbreak " them from regional blocks to watch global TV via VPN too.
THE ISSUE
So, faultless install, but the cable and WiFi internet just won't work beyond brief uptime, like a minute or two, although the LEDs are on. Note that this same problem existed BEFORE on the Linksys, when it had just been refurbished with the latest OEM firmware, I had previously recovered it after a storm power surge rendered it bricked.
It also has a loud fan on startup that goes away after several minutes. I mention this as it may be "mechanical" rather than firmware, but I suspect a faulty component would be far more devastating, so I think there's some ISP end incompatibility?
MY SITUATION SO FAR
Check to see if your LAN and WAN ports are in the same address range.
They are not, but there is no 'solution' in the documentation. It only says:
" * If these two addresses are in the same range, e.g., if they start with the same three sets of numbers, then they are in the same address range. You need to change the address of the LAN interface (see next step)."
So I did this anyway, and rebooted into 192.168.2.1
"* If the address ranges do not conflict, then ask on the [OpenWrt Forum]"
They DO conflict, so how to change them? They look like 10.XX.XX.XXX
Also read a very complicated document on here about IPV4 and NAT and I think this may be part of the problem, but really hope it is not because the fixes seem either very complex, or seem to defeat the point of OpenWRT. also I don't game, so everything should work like before. But it's possible I'm just confused at this point with new info overload.
I also saw a solution on reddit that's 3 years old where someone said PPOE needs to be set up but they didn't elaborate.
I hope all this info helps you to help me. Thanks.