Can't ping new 18.2 install [SOLVED]

[lemmingNO3]

Linux Mint 18.2
AMD64 8 Core 4.0GHz, 16GB Ram, 2x2TB drives
Manually assigned IP address using the Connection Icon graphic
Lives on a hard wired local network currently having 4 other Linux Mint computers

This system was running Linux Mint 18.1 but it's '/' partition has become too small as versions have changed and grown in size and I was getting warning messages about running out of '/' room, so I installed Linux Mint 18.2 and expanded the '/' partition and thereby also changed the rest of the partition sizes on the 1st drive. I plan to do this on all my systems as the suffer from the same problem now...but-

I can not ping (or ssh to) the New Install from any of the other computers on the network...'Destination Host Unreachable'.

However, the New Install can ping my other computers and it can access the Internet. BUT, the New Install can not ssh to any of my computers reporting that the 'Connection Timed Out'.

I could use some help on debugging this, and also, I was wondering what configuration file the Connection Icon graphic is entering it's information into....as I'd like to be able to edit it directly with an editor since the Connection Icon is kind of screwy in how it operates on all of my machines...at least is has been for the last few versions that have come out. For instance, I enter '255.255.255.0' in the network mask, along with my other info and save, but if I go back to look at it using the edit button later, it says '24' instead! But if I fiddle around trying to see it from other avenues, it sometimes shows the proper '255.255.255.0' entry. In fact, trying to enter IP addresses seems to be more of an art form as everything is moving around as I try to enter different field information and being covered up....it's disconcerting and I have to often start over. -Or I am doing something horrible wrong in trying to use it.

Thanks for your help!

[tovian]

http://whatismyipaddress.com/cidr

For instance, I enter '255.255.255.0' in the network mask, along with my other info and save, but if I go back to look at it using the edit button later, it says '24' instead!

Those are different ways of "saying" the same thing. If you want to understand this (known as CIDR notation) have a look at THIS PAGE
- or do a Google search on CIDR notation and read some of the other explanations.

[lemmingNO3]

thanks tovian I will read up on it.

By going to Configurations icon then clicking on the Network icon, I discovered that my address of 192.168.2.110 was actually showing up as 192.168.2.199, which is why I could not ping the new install, even though the Connections icon approach was showing 192.168.2.110 !!! However, I discovered that if I rebooted, even the Connections icon was actually showing 192.168.2.199 ! And in fact, it wouldn't actually change my IP to 192.168.2.110 until (after i saved) I also rebooted....THEN every place I could look at the IP address on the new installed machine agreed that my local network address was 192.168.2.110 and then, and only then, was I suddenly able to ping the machine and get a positive response....plus ssh-ing into the machine then worked also.

Is it possible to manually edit the config file with a plain text editor that the graphic Connections icon is attempting to add my info into....so that i could simply go there and skip using the graphic Connections icon for entering my IP info? And if so, what is the path to it and it's name? (I want my connected icon to continue working for visual confirmation I have a connections....I just want to manually do the setup. Is that possible?)

[tovian]

In order to see all the IP's in use on a LAN segment - for many years I have used (on Windows and Linux) a utility called IPScan (by AngryZiber). It is still being maintained and even ugraded - and it's FREE.
HERE is a link to their downloads page.
It requires minimal setup - basically just the IP range of your LAN.
It has many useful options, for instance:
You can right-click IP's that are shown and open them with your default internet browser or your file browser (whichever is appropriate)
The more you play with the program the easier it is to understand.

2 cautions...
1. Many AV's see this as a hacking tool (used the wrong way it might be dangerous)
2. Go to Tools>Preferences and tick the box for "Only Alive" so you don't get a report on EVERY IP on the subnet.

[lemmingNO3]

Sweet! Thanks tovian! It works great!