Much to my surprise, I do have inxi installed. Had never heard of it.

CPU~Dual core Intel Core i3-4030U (-HT-MCP-) speed/max~800/1900 MHz Kernel~3.19.0-32-generic x86_64 Up~11:07 Mem~1600.7/15969.4MB HDD~2000.4GB(38.1% used) Procs~183 Client~Shell inxi~2.2.28

Plan to do syslog in the morning, maybe that will turn up something.

That didn't report the network device unfortunately. Run the lspci command I gave you.

lpsci results:
lspci -nnk
00:00.0 Host bridge [0600]: Intel Corporation Haswell-ULT DRAM Controller [8086:0a04] (rev 0b)
Subsystem: Lenovo Device [17aa:390b]
00:02.0 VGA compatible controller [0300]: Intel Corporation Haswell-ULT Integrated Graphics Controller [8086:0a16] (rev 0b)
Subsystem: Lenovo Device [17aa:390b]
Kernel driver in use: i915
00:03.0 Audio device [0403]: Intel Corporation Haswell-ULT HD Audio Controller [8086:0a0c] (rev 0b)
Subsystem: Lenovo Device [17aa:390b]
Kernel driver in use: snd_hda_intel
00:14.0 USB controller [0c03]: Intel Corporation 8 Series USB xHCI HC [8086:9c31] (rev 04)
Subsystem: Lenovo Device [17aa:390b]
Kernel driver in use: xhci_hcd
00:16.0 Communication controller [0780]: Intel Corporation 8 Series HECI #0 [8086:9c3a] (rev 04)
Subsystem: Lenovo Device [17aa:390b]
Kernel driver in use: mei_me
00:1b.0 Audio device [0403]: Intel Corporation 8 Series HD Audio Controller [8086:9c20] (rev 04)
Subsystem: Lenovo Device [17aa:390b]
Kernel driver in use: snd_hda_intel
00:1c.0 PCI bridge [0604]: Intel Corporation 8 Series PCI Express Root Port 1 [8086:9c10] (rev e4)
Kernel driver in use: pcieport
00:1c.2 PCI bridge [0604]: Intel Corporation 8 Series PCI Express Root Port 3 [8086:9c14] (rev e4)
Kernel driver in use: pcieport
00:1c.3 PCI bridge [0604]: Intel Corporation 8 Series PCI Express Root Port 4 [8086:9c16] (rev e4)
Kernel driver in use: pcieport
00:1f.0 ISA bridge [0601]: Intel Corporation 8 Series LPC Controller [8086:9c43] (rev 04)
Subsystem: Lenovo Device [17aa:390b]
Kernel driver in use: lpc_ich
00:1f.2 SATA controller [0106]: Intel Corporation 8 Series SATA Controller 1 [AHCI mode] [8086:9c03] (rev 04)
Subsystem: Lenovo Device [17aa:390b]
Kernel driver in use: ahci
00:1f.3 SMBus [0c05]: Intel Corporation 8 Series SMBus Controller [8086:9c22] (rev 04)
Subsystem: Lenovo Device [17aa:390b]
02:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 10)
Subsystem: Lenovo Device [17aa:3821]
Kernel driver in use: r8169
03:00.0 Network controller [0280]: Intel Corporation Wireless 3160 [8086:08b4] (rev 93)
Subsystem: Intel Corporation Dual Band Wireless AC 3160 [8086:8270]
Kernel driver in use: iwlwifi
---------------------------------
syslog results--before connection
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: Internet Systems Consortium DHCP Client 4.2.4
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: Copyright 2004-2012 Internet Systems Consortium.
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: All rights reserved.
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: For info, please visit https://www.isc.org/software/dhcp/
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient:
Apr 4 07:30:27 morgan-Lenovo-G50-80 NetworkManager[1051]: <info> (eth0): DHCPv4 state changed nbi -> preinit
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: Listening on LPF/eth0/50:7b:9d:00:c6:2d
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: Sending on LPF/eth0/50:7b:9d:00:c6:2d
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: Sending on Socket/fallback
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0xde49a472)
------------------------
after connection--but not usable
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: Internet Systems Consortium DHCP Client 4.2.4
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: Copyright 2004-2012 Internet Systems Consortium.
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: All rights reserved.
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: For info, please visit https://www.isc.org/software/dhcp/
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient:
Apr 4 07:30:27 morgan-Lenovo-G50-80 NetworkManager[1051]: <info> (eth0): DHCPv4 state changed nbi -> preinit
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: Listening on LPF/eth0/50:7b:9d:00:c6:2d
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: Sending on LPF/eth0/50:7b:9d:00:c6:2d
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: Sending on Socket/fallback
Apr 4 07:30:27 morgan-Lenovo-G50-80 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0xde49a472)
--------------------------------
Apr 4 07:30:42 morgan-Lenovo-G50-80 NetworkManager[1051]: <warn> dnsmasq appeared on DBus: :1.42
Apr 4 07:30:42 morgan-Lenovo-G50-80 NetworkManager[1051]: <info> Writing DNS information to /sbin/resolvconf
Apr 4 07:30:42 morgan-Lenovo-G50-80 dnsmasq[2481]: setting upstream servers from DBus
Apr 4 07:30:42 morgan-Lenovo-G50-80 dnsmasq[2481]: using nameserver 192.168.0.1#53
Apr 4 07:30:42 morgan-Lenovo-G50-80 dbus[888]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
Apr 4 07:30:42 morgan-Lenovo-G50-80 kernel: [ 101.560736] nf_conntrack: automatic helper assignment is deprecated and it will be removed soon. Use the iptables CT target to attach helpers instead.
Apr 4 07:30:52 morgan-Lenovo-G50-80 NetworkManager[1051]: <info> (eth0): IP6 addrconf timed out or failed.
Apr 4 07:30:52 morgan-Lenovo-G50-80 NetworkManager[1051]: <info> Activation (eth0) Stage 4 of 5 (IPv6 Configure Timeout) scheduled...
Apr 4 07:30:52 morgan-Lenovo-G50-80 NetworkManager[1051]: <info> Activation (eth0) Stage 4 of 5 (IPv6 Configure Timeout) started...
Apr 4 07:30:52 morgan-Lenovo-G50-80 NetworkManager[1051]: <info> Activation (eth0) Stage 4 of 5 (IPv6 Configure Timeout) complete.

When posting commands/output, you should use code tags to preserve formatting. This is the relevant lspci output for your ethernet hardware
As suspected it is a Realtek device using the r8169 driver. The Linux Mint thread I linked to in post #21 discusses the same hardware issue and symptoms.
Your syslog output shows DHCPDISCOVER requests, but I'm not seeing any DHCP leases obtained.
Did you omit some of the output?

I read thru the whole link you gave me and, as I understood it, I have to replace the r8169 with a different driver. Checked Realtek sites and need to know which one, but looks simple enough? As you've probably guessed, my terminal experience is practically non-existent and I was hoping for a simpler solution. Synaptic Package Manager has about 10 different network managers and I'm not sure which one I could use, that might be easier than doing some command line stuff. I know where the r8169 files are, just not sure how to get rid of them and be sure I have the correct Realtek driver. But, if that's the only option, I'll have to do it.

It's entirely possible I cut off some portion of the results from this morning. I should never try something like that before caffeine.

You could do that but you do need to be confident with compiling/installing from a terminal. It's not rocket science but it does take some practice/experience (as with anything really).

You could do this, and it is usually just a matter of blacklisting the unwanted driver (in a file in the /etc/modprobe.d/ directory).

However, I'm wondering if it might be worth testing with a newer kernel via a live distro (USB stick). That way you can test if the ethernet hardware behaves as expected from boot (along with any other issues) without committing to an install...

http://landoflinux.com/linux_install_mint_18_sarah.html

I know the feeling!:)

No doubt have some heavy duty reading ahead of me. I was wandering around the Ubuntu forums and came across one person that had problems with the 8169 reinstalling itself even if blacklisted. Cross that bridge if I get to it, besides only 1 thread.

My current plan: backup data files to my backup external hard drive, probably not necessary, but using Windows has made me forever paranoid. I have another external hard drive that I want to install Mint 17.3 on and do all my practicing from there. I don't see how I could screw much up doing it that way, keeping everything completely separate. Meanwhile, I can still get on the internet when I want to. Any flaws there?

I have that chipset on this e1-1500 gateway. amd chipset name. It works fine under debian jessie. But I tend to stop any managers and configure it manually.

Why not try Mint 18? With a newer kernel you might just find it plays nicely with your NIC.

I have an ISO of 18 that I've been playing with, but jury's still out. I really like 17.3 and wanted to duplicate current setup as close as possible. Before I install 18 I want to be sure all the software I routinely use won't have been abandoned in 18. The thought that 18 might just cure this issue occurred to me, however solving one problem while creating several others doesn't seem like fun. Every time I update FF, it loses/changes some of my preferences/config changes, so taking a hard look before I leap. But, I still love Linux. So, my thinking is to work with 17.3 (learn a lot in the process) then move on to 18. The only time I have installed Mint was doing a clean install, so never had to do an ISO upgrade, this will give me a chance to do that without actually bombing anything. If I mess that hard drive, no harm no foul, just start all over.

Ok, no harm in tyring that I guess. However, Mint 17.x uses quite an old kernel, so it might be worth a shot to try a recent stable kernel as part of this experiment. It's explained how to do that here...

https://mintguide.org/system/686-ins...inux-mint.html

I think you're right. I was looking at the available kernel list in the Update Manager, got a big surprise, way more of them than I would have thought. Decided to take another run at 18 and immediately ran into a problem. Cinnamon keeps crashing so no dice. So, then I downloaded a brand new ISO 18.1, same thing. What makes that frustrating is that I have previously run 18 from my DVD drive without any glitches. Now it won't work.