Network Unreachable error

Here is something that can help if you get an error when trying to start CommandCNC, and it has a line in the error message like this: hm2_eth: rtapi_app_main: Network is unreachable (-101) You might get this error if you had to install a new ethernet card in the computer, or if you have two ethernet interfaces in the computer and you plugged the ethernet cable from the control box into the wrong port in the computer, or if you moved a hard drive with linux and CommandCNC from one computer to another one – etc. In Linux the ethernet interfaces are referred to by names such as eth0, eth1, eth2 etc.   If your system has eth0 set up with the right IP address to talk to the control box motion card, and for any reason (such as mentioned above) the name is now eth1, then you will need to remove the settings from eth0 and set up eth1 to talk to the control box. Fortunately we have a script on the system which should fix the problem. If you are running CommandCNC version 0.8.6 or later, there is a menu item in the CNC menu called “CommandCNC Ethernet Port Setup”: 1) Make sure the control box is all connected and the power is on. 2) Go to the main menu on the computer, find the CNC menu, and click on “CommandCNC Ethernet Port Setup” 3) Enter the system password when asked for it. If you are running a version of CommandCNC older than 0.8.6, you will instead do the following steps: 1) Make sure the control box is all connected and the power is on. 2) Open a Terminal (Terminal Emulator in the main menu of Linux) 3) type the following: sudo ccc_mesafind 4) press the Enter key, and enter the system password when asked for it. The ethernet motion card in the control box is a model 7i92, so if it says it found a 7i92 that is good.  Below is the full output of a successful run of the script below so you can see what it should look like.
plasma@plasma-mcklab:~$ sudo ccc_mesafind [sudo] password for plasma: network-manager stop/waiting Checking eth0 for 7i92… Found a 7i92 on eth0 Checking Network Interfaces (this may take a minute)… Network Interface information found… There are 2 network interfaces. Preparing to reconfigure… ***Network Interface Reconfiguration Complete*** network-manager start/running, process 2849