"I was having trouble with my Local Area Network..."

It might help if you described the issue.

Thank you, Elmer. I did the searches you mention and I mostly found software which I could get a free trial version, but not a permanent version. If possible, I like to use the built-in software which is part of the OS if possible. I'll check logging in to my router.

If you go about halfway down the page in this link, there's a list of free, open source solutions. I don't know which or if any there are useful but you can explore.

Free and open source mapping

If you are looking for IP to host name resolution (DNS) for your local LAN you can map these in your HOSTS file. Just Google "hosts file windows" (no quotes).

I'm not familiar with the Hosts function but I go about it a different way. Two different homes, two different routers (one up-market and one mid-range) and both allow assigning names to devices. The names seem to be associated with the MAC addresses rather than IP addresses. This would be an advantage if Hosts uses IP addresses because in the case of a device connecting, disconnecting, then reconnecting to the network (as when turned off then back on or a portable device that leaves WIFI range and comes back) or of rebooting the router, whether deliberately or as a result of a power hiccup, a given device without a fixed IP address isn't guaranteed to reconnect with the same IP address as the last time. And often won't. I take devices from one home to the other and of course the IP address in a different network will be different.

With router identification that uses unique MAC IDs, the device's prior IP address in the same or different location doesn't matter. Additionally, if I want the at the moment IP address of a particular device, I can access the router from ANY connected device, no matter what its OS, and get the info.

*- "if I want the at the moment IP address of a particular device..." this is useful for me because I have some devices that I log on to over the network and I need to know which IP address to use. An example is the cell phone range extenders I have in each location, the status and function of which I check once a week but that can only be done by using the current and correct IP address over a LAN connection.

Bababing2, I looked at the hosts file and it appears to not have changed since the computer was purchased, nothing about my current network.

I have a network-connected device, but I can't tell if it's connected. I have a couple which, if I type their IP address into my browser, the login for that device appears, but if I type in one which is not connected, then after awhile, it times out. It's terribly tedious to go through all the numbers and get only a few "hits", which is why I want software to find this information. Whois doesn't seem to work. And Elmer, if I look for the list you link to, I get a page which is actually two pages overlaid and I can read any of it.

Would nmap do what you want?

https://nmap.org/download.html

Using the GUI (zenmap) and doing a ping scan on 192.168.1.0/24, this is what I get.

I can see any device that admits to being alive. (by responding to the ping)

If the image is not clear, the command is:

nmap -sn 192.168.1.0/24

Of course if your private IP range is something other than 192.n.n.n, you'd need to edit.

If you wish to assign a name to your devices instead of using the IP address then the 'hosts' file can do this name-to-number mapping for you.

For example you would edits 'hosts' and add:

192.168.1.100 mydevice

192.168.1.101 mydevice2

Then open a CMD prompt and "ipconfig /flushdns" to so it will re-read the file and you can

"ping mydevice" instead of "ping 192.168.1.100" to tell if it's connected. Or http://mydevice in the browser.

You're probably using DHCP for dynamic IP assignment but I doubt it will be necessary to setup a table of fixed address exceptions in the DHCP config so it won't get a different dynamic address. I'm willing to bet the addresses will stay with the devices but accurately this is the 'right' way.

Here's a list of freebie network mapping software for Windows

https://www.goodfirms.co/blog/best-free-and-open-source-network-mapping-software

I had thought that the hosts file was dynamic, updated as new IP connections were made, but I guess not. The specific problem is that there is a device on my network which isn't working and I was trying to find the IP address to help track down the trouble.

mtvhike, the host file isn't dynamic, but your dns "cache" is (in memory). The cache will include the host file entries plus all the ip addresses you've connected to since the last flush or network restart.

Edit: IIRC, there is a ttl (time to live) for entries in the cache OTHER than the host file entries. Don't remember what the ttl is, maybe 24 hrs. I assume the ttl is there so the cache doesn't get too big.

"Elmer, if I look for the list you link to, I get a page which is actually two pages overlaid and I can read any of it."

Sorry. I tried the link both from an Android phone and from a PC, using both Firefox and Chrome, worked fine from all three. Try a different device or browser.

"I have a network-connected device, but I can't tell if it's connected."

Honestly, don't over-complicate this. Sign in to your router and you can see everything that's connected. Most routers will also allow you to assign names. Any connected device will give you its network IP address or you can track them down using the MAC addresses, also should be visible from most devices. Or, turn off everything and then turn them on one at a time. New items visible are what you just turned on/connected.