For the horizontal portion of the cable run this can involve drilling holes in the joists where the cable will pass.
Run ethernet from basement to attic.
When necessary use existing ducts or pipe runs to get wires from the attic into the basement.
If the rooms in question are wired for coax you may be able to sneak the ethernet cable down the wall through the existing hole in the top plate of the wall s.
You want to run solid cable in the walls attic between your terminations jacks.
When adding or replacing wiring in finished walls most electricians will attempt to make the horizontal portion of the cable run in the unfinished attic or basement crawlspace areas looping the cable down or up through the wall cavity across the floor or ceiling joists then vertically through another stud cavity to the next wall box opening.
If you are setting up a new wired internet connection network at your home or office then check this guide on how to run ethernet cables between floors.
On the first floor run wires up the wall from the basement.
Attach the wire or cable to a fish tape or coat hanger using electrical tape and feed it into the hole until it reaches the opening at the other end.
If you re working from the attic you can drop a weighted string down wall cavity then attach the wire to the string and pull it through.
On the second floor run wires down the wall from the attic.
If you have access to your basement crawl space and attic you should be able to run wires without having to cut patch any drywall.
Run the wire or cable to its destination.