Did your problem start straight after install of those updates??

I wasn't sure if you meant updates for your router/modem or your system on your laptop itself, being the reason I was confused about that.

So, you are currently connected to the internet. Why did you think you weren't?

Decided I was getting buggy looking at this, so took a break. First thing this morning I fired up the Lenovo and did the ping again. Results:


PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data.
64 bytes from 192.168.0.1: icmp_seq=1 ttl=64 time=1.00 ms
64 bytes from 192.168.0.1: icmp_seq=2 ttl=64 time=0.398 ms
64 bytes from 192.168.0.1: icmp_seq=3 ttl=64 time=0.354 ms
64 bytes from 192.168.0.1: icmp_seq=4 ttl=64 time=0.315 ms
64 bytes from 192.168.0.1: icmp_seq=5 ttl=64 time=0.381 ms
----------------------------
ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
From 192.168.0.1 icmp_seq=1 Destination Net Unreachable
From 192.168.0.1 icmp_seq=2 Destination Net Unreachable
From 192.168.0.1 icmp_seq=3 Destination Net Unreachable
From 192.168.0.1 icmp_seq=4 Destination Net Unreachable
From 192.168.0.1 icmp_seq=5 Destination Net Unreachable
-----------------------------
ping google.com
PING google.com (216.58.217.14) 56(84) bytes of data.
64 bytes from den03s09-in-f14.1e100.net (216.58.217.14): icmp_seq=1 ttl=57 time=10.3 ms
64 bytes from den03s09-in-f14.1e100.net (216.58.217.14): icmp_seq=2 ttl=57 time=10.4 ms
64 bytes from den03s09-in-f14.1e100.net (216.58.217.14): icmp_seq=3 ttl=57 time=10.5 ms
64 bytes from den03s09-in-f14.1e100.net (216.58.217.14): icmp_seq=4 ttl=57 time=10.7 ms
64 bytes from den03s09-in-f14.1e100.net (216.58.217.14): icmp_seq=5 ttl=57 time=10.2 ms

They look slightly different. Thought the problem still there. Went to make coffee and when I came back 10 min later, the modem lights were all lit up. Everything now works. Since I already tried all the modem things, this makes no sense. So, I shut down both laptop and modem, rebooted the whole thing, twice. Same deal, there's a 6 min delay between laptop getting connection and being able to use it. Is that even possible?

I'm not quite sure what you mean by this. Are you referring to being able to browse a given site? Is this particular sites? Sesssion-related perhaps?

The only 2 programs I use for the internet are Firefox & Tbird. I turn on the computer and, normally, I can check email & get on internet right away. For the last week, when I launch one of them, Tbird won't check email and FF can't load a web page. And there's an indicator light on the modem that goes on when there's an internet connection. No light. Mint says I have a connection. So, one of them is wrong. Since Mint has been operating trouble free for months, I thought it was the modem. Tried that, unplug/reset etc, no luck there. So, started looking at Mint. I used an old laptop to get on the internet, no connection problem with it. As soon as the older laptop starts a connection the newer one can use that. So, basically, I've been using the older one to get a connection and using the newer one after that. This morning, quite by accident, I discovered that if I wait long enough the newer one can get a usable connection. I timed it and it takes 6 minutes between the time I turn it on and the connection will actually work. I've done some testing from suggestions I got here, searched the internet, and looked on the mozilla forums, but no one seems to be having that kind of problem.

I think I'm going to flag this as resolved, even tho it's really not. I'm going to spend some more time looking at other forums and then return when I get a better (or any) idea about what the problem might be. At this point, I'm clueless about what it might be or where it even is.

It is certainly a strange issue. Perhaps a quirk of the NIC hardware...
FWIW, here's a thread where the user with a laptop using Realtek ethernet chipset (r8169 driver) was experiencing connectivity issues, but found that unplugging/plugging the ethernet cable (or invoking ifdown eth0/ifup eth0) would result in a working connection
https://forums.linuxmint.com/viewtopic.php?t=189257

I'll definitely read that. So far, I think I have 2 possibles. My ISP changed something about the modem--didn't tell/ask me. Imagine that. Or, since I've done 2 FF and 1 Tbird update in about the right time frame, makes me wonder. Usually FF will change something when I do an update, it's always a cosmetic preference. Missing toolbar, that type of thing. Looked at my update history, there's more than I thought and it will take me some time to go thru and look at everyone of them. That's my plan and I already know how long it takes to check all the FF config!

Share your ethernet hardware details when you get a chance. We can examine the syslog messages for clues about what is happening regarding DHCP leases etc

Spent hours looking on the internet, not having any luck. People are having similar problems, mostly wireless. My Compaq has 2 DNS numbers in the network settings but the Lenovo (new) only has 1. That's in the details option. Could that make a difference?

Ignore last message. As soon as the connection is usable, the second DNS number shows up in the network settings. So, the delay must be in the acquisition of the second DNS number? Is that going to be something in FF or Linux itself? (trying to narrow down the search)

#13 suggests that you are on the internet. So something else is in the way. Firewall? MTU size? For each layer of NAT you should subtract 40 (or 60) from the default MTU of 1500.

$ sudo ifconfig enp1s0 mtu 1440

Each layer of nat adds a TCP/IP header. So you could be sending one big and one small packet instead of one packet. And on a high packet loss connection issues arise. The server on the other end isn't able to assemble the packet again and just ignores you. Smaller packets have more overhead (headers), but you can get better queuing and more responsiveness on a slow connection. With the MTU on a dialup connection being 576
back in the day. Which oddly works when certain sites (*cough* pogo.com / sony *cough*) are mis-configured.

The delay you mention is associated with the DHCP communication which provides the IP address and DNS address(es). You could keep a watch on the syslog to see what messages are reported with respect to dhcp. Open a terminal and run it as soon as you've logged in and before the connection is active...

or filtered for dhclient/dhcp messages
You still haven't given us your ethernet hardware details as requested in post #21. I'd like to know the driver details.

Can't find anything to tell me where I can find ethernet hardware details. Could it be called something else?

The MTU is set at 'automatic'. Ditto for the old laptop that I'm running parallel, trouble free. So, I'm guessing that's not it, but I'm keeping it in mind just in case.

$ sudo ifconfig enp1s0 mtu 1492

Long ago with certain early broadband providers, that trick give you a notice-able bump in throughput. Even if it's not the "issue", it is worth fiddling with from time to time.

$ dmesg

Normally has some information on ethernet. Like the driver used, the firmware loaded (or missing), and other things.

$ lspci -nnk
$ lsusb
$ lsmod

# egrep -r -i enp1s0 /var/log/*

Replace enp1s0 with whatever udev called your device.

# ifconfig -a
$ ip link show

The one(s) that starts with e is/are the ethernet one(s). With w* for wireless and lo for the local loopback networking that allow for so many more things than windows has delivered. One you know the module name of the ethernet driver you can do a lot more research, like checking for alternate drivers on github. Like checking for other firmware that might work better. Like checking for what modinfo says about it in terms of options and parameters. Or just checking the kernel source tree for clarification and errors. Although most of that can be gleamed by googling the vendor:device name outputted by lspci or lsusb. It's a dual hex value FFFF:FFFF specific to your hardware. [10ec:8168] in my current hardware.

Do you not have inxi installed? (Post #21)

You can also use lspci and filter for network class (02) PCI bus connected devices like this...