On Sun, 30 Sep 2012 16:44:16 -0700 (PDT), klem kedidelhopper
wrote:

I have to install an Internet connection at a location somewhat
removed from the origination point. The building is very large, spread
out, and difficult to run wire through. Presently there already is a
connection terminated in an Rj45 at a point that is only used for one
week out of every year. All other times there is nothing plugged into
this jack but the connection remains active. In order to make the
connection to the new location about 100 feet away can I tap off the
existing jack and "daisy chain" the wire to the new location and then
terminate that wire in a second R45? I now this is not common practice
but if only one computer is using the line at any particular time
would this work? There will never be a time that two computers will
ever be operating on this line at the same time although for that week
in question they both may be plugged into it though. would this be an
issue? I can arrange to have the new location unplugged during this
time if need be. Thanks for any advice. Lenny

Many desktop computers gave a "wake on LAN" feature in their network
card, co that type computer would always be online.

There is a device that can spli a single RJ45 into two lines. You
might want to check into that. ry cyberguys.com as a source.