So, you have a connection. And you have another network that doesn't work. You want to get the other network working? If your interfaces have IPs, wherever they got the IPs from should also be where they get DNS. If the network interface(s) have no IP, they have to get one from the router or modem. Now, somewhere in this there is a smart phone that is also a wireless hot spot. Depending on what the phone connects to, wireless or wifi, it might not have configured DNS.

Network Manager is a service. It sits in the system tray as an icon. But you can click on it and it should open up. OR, it's possible that XFCE doesn't use NM. I'm not sure on that one. I'm also not sure why a power manager would have a networking icon.

I'm sorry if I misjudged your experience level, or if you perceived that I did. I'm really having an extra difficult time making sense of this entire thread.

So,I may be missing something obvious, but this is the only thing I've seen as far as a GUI to manage wireless networks, via the tray icon as shown. Now, aside from this menu popup, there are a couple detailed windows to access information about the connections that are there, add a hidden network, VPN connect, other items on the menu. These functions can all be accessed from this window. Is this the network manager? Because if so, then it's lacking the one thing I actually need which is a simple way to force a scan for available networks. The window above is titled "Network Connections" in my settings menu, and there is a menu entry for "Network" under settings which runs the command nm-applet, but this shortcut, and the command in question both produce no apps at all. When I type it in under a terminal, it returns me to $ prompt. If this isn't the network manager, then I'll happily install that, or whatever other package will give me a controllable interface that gives the option of on-demand searching, etc. I've actually even gone so far as to try installing network-manager using apt-get and it says it's already installed, but typing the command network-manager into terminal says command not found.

Mod please delete this post, fix was posted prematurely, didn't work.

Yes, that is network manager. NM-applet puts the network manager applet in the system tray. Go into 'edit connections' look at the configuration of the wireless connection. See anything amiss? If you want to rescan for wireless APsTo find the device nameAlsomight be helpful. It's a real swiss army knife of networking fu.

Apologies for the long hiatus, but hopefully someone who can help is watching this still. I managed to get the second network (the closer one) working, which now gives the benefit of additional process of elimination troubleshooting. So, as I understand it, /etc/resolv.conf should point to loopback, 127.0.0.1 and based on the file, that is a symlink to /run/connman/resolv.conf which is written by the connection manager service. So does that mean that there's something wrong with the connection manager, and, if so, how do I fix it? Or is there an alternate system level tool to manage my connections? Theoretically, DHCP should be handling connection details, and I even went so far as to add additional DNS to my connections in connman. Is there a deeper configuration issue with my tcpip stack that's at heart here?

Basically, aside from learning a little more connection information, I've not gotten anywhere thus far. Ultimately I still need to figure out how to get my DNS assigned correctly, so I don't have to manually edit resolv.conf by hand every day. So what do I need to do?

Also, I don't know if this helps, but I did run a full connection info sheet out last night into a text. If someone can tell me what specific information is most needed, I'll gladly post whichever parts, or the entire sheet. I don't remember exactly what code I used, but if I recall it was nmcli device show >>/*path*/info.txt. This enabled me to see a lot more details on the actual wifi connection, and I can see the DNS it references was 192.168.254.254, I don't know if that's the problem or not, but considering that all the other devices in the house (xbox, switch, everyone's phones and tablets, other people's computers) can connect to either connection, I'm POSITIVE that it's a software issue on my side. I keep finding people talking about dnsmasq and some say uninstall it, some say switch the system to use it exclusively, and others still have suggested write-protecting resolv.conf with a manually coded IP as the DNS. While I'm sure the latter of the options would actually allow my computer to connect without manually rewriting resolv.conf, I don't just want to slap a band-aid on the problem and call it a day. Ultimately I want to find the cause, not patch the sumptom.

If you installed alot of packages by default, you may have had a DNS server running on your machine.
If you then did DNS through that server, it will bounce it to the next DNS server that it knows about
when it does not know the name. This continues until it one of DNS servers finds a cached entry, or reaches the actual host site.

When you messed with your installation, you must of lost your local DNS server that you were running.

I suspect that doing DNS to 127.0.0.1 was reaching the DNS server running on your machine.

Running your DNS through a local server (that then bounces the DNS to google) was not doing you much good.
A local DNS server is only good if you actually keep a number of machines from going to the outside servers, or if you have
some local machines whose names you need to lookup from other hosts. I doubt you have either of these situations, so leave it off.

So I've done a lot of tweaking, a lot of uninstalls and reinstalls of various services. Ultimately the steps that seem to have, thus far, actually resolved my issues was to
In case for some reason it didn't go away
Create the link to resolvconf instead.
Then a reboot.
Now /etc/resolv.conf is being written by resolvconf, and everything seems to be working. I'm sure there are other solutions, and it wouldn't surprise me if I caused other issues, but for now, domain resolution is working, and I can easily switch to either network.

Since the time of my last post, I've had zero issues with name resolution. I don't have the deep level knowledge to know why, but I do know that by limiting dns resolution the way I have, my problem has been fixed. My solution is here.