First post. Hopefully I've explained everything clearly.
I have PC that I use infrequently. I have Ubuntu Mate 16.04.3 installed (I think 16.04.2 was what was installed initially, but up was updated).
On the machine I run the internet through a VPN service, for which I use via OpenVPN. I have the DNS running through Network Manager. I was happy I had a secure VPN set up, after checking at https://ipleak.net/ I didn't have any leaks - I took care of things like turning off WebRTC, disallowing IPv6, and I also used UFW to block off all traffic that didn't run through the VPN, so if the VPN is down, no internet.
So, everything seemed fine, I had a machine that I thought had a secure VPN set-up...until about 4 weeks ago (it might have happened earlier and I hadn't noticed), because now, on, checking at ipleak, my PC has developed a mysterious DNS leak. I end up with "DNS Addresses - 2 servers" instead of one, and one of those servers, although isn't my unmasked ISP IP address itself, it is, on checking, owned by my regular ISP, so I assume it's probably my ISP's DNS server? (Sorry if I'm getting any terminology slightly wrong, as I don't have massive experience/knowledge of VPN systems or DNS).
Also, one other slight oddity and concern that I think is worth mentioning on is that I now don't seem to be able to turn off auto-updates, and in spite of this, the DNS leak "bug" has not been rectified. If I go into the "Updates" tab under "Software & Updates" in Administration, I try to make changes in "Automatically check for updates" drop down menu, from "Daily" (which I'm not sure I actually set it to) and try to change it to "Fortnightly" it refuses and stays set at "Daily". Same goes for "When there security updates" when I try to change it to "Download and install automatically" to "Display Immediately", it also refuses to change. When I tried to make such changes in the past, not unsurprisingly, I got an "Authenticate" dialog popping up, asking me to give my administrator password. No such dialog pops up anymore, it now just refuses to let me make any changes. I thought it was worth a mention, just in case there's a connection.
Might be also worth mentioning that I have Cinnamon desktop also installed, which I'm currently using instead of Mate - I've checked though, and it is misbehaving in both Cinnamon and Mate, so I don't think that could be the issue.
So, guys, any idea why my machine has suddenly developed a DNS leak? Is there perhaps a new Network Manager option I now have to change to get my DNS back on the secure side?
Oh, and as a couple of side questions that have been bugging me. I use Network Manager for my DNS , but where does Network Manager get it's DNS information from? Also, is there a way of setting OpenVPN to auto-reconnect to my VPN provider if there's a disconnect when using it the way I do, through Network Manager?
Thank you for any help.
ROUTER_IP
variable.