Linux Router

I took a old desktop computer and made it into a Linux router, I installed a vpn on it and did some monitoring, this is geared more to the folks who run their own equipment, i have the Xb6 gateway and it was running flawlessly, I put it in the Bridge mode and hooked up the Linux router and rebooted. Everything and it was working good. I was monitoring on a iPad, I got good speed for using a vpn, but I noticed random disconnects, I figured out the stock DNS settings worked, but weren't exactly right. I would get a connected but no internet warning, I discovered I could add google name servers 8.8.8.8 to my iPads DNS and it would start working, I did some search on the internet and found a fix for the router and my vpn. Now it works perfect. Also I would notice slow internet and found out it had changed over to XFINITY WIFI. My point is all my disconnects were caused by a working but flawed DNS setting in my router. So if your running your own equipment beware of all the default settings as they can be part of your problems. This would apply to a store bought router also.