[Tuxaloosa] Network Troubleshooting and Ethernet

[Edward Terry]

Is there anyone on the list, or can anyone recommend someone, who can 
troubleshoot a Linux network connection and also run Ethernet cable in 
three houses?  The network is between two desktop computers (both 
running Linux Mint) in two different rooms, connected by Ethernet; it 
previously worked but no longer does.  Comcast is the Internet provider. 
  All computers involved run either Linux Mint or Ubuntu.  The Ethernet 
cable needs to run from the room with the Comcast modem to the room with 
the television, and Ethernet jacks need to be installed in both rooms. 
I appreciate any help or recommendations.

Edward Terry