I want to have Ethernet wired speed at the other end of the barn. It is farther than 300 ft. that the Ethernet wire can perform.
Ken you keep using the word barn. When did you ever have a barn? OK the specification for wired Ethernet does say 300+ feet. The newer Ethernet cables like CAT 6 or 7 will probably add some distance to the signal but you may give up some speed and quality.
If you can place another switch in between the cable at 250 ft that will solve the problem, but I am sure you don't have electricity in the pasture.
I do have a problem like this and I found some electronic solutions that provide running Ethernet over a single pair of copper wires. The product is called StarTech Ethernet extender kit and cost about $225.00. It consists of two devices, one in the farm house and one in the barn. All you need is a pair of telco (2 wires) and electricity from the wind mill and you can have Ethernet for over 1 mile.
OK I will stop the farm jokes. It works for me at 700 ft. I don't get 1G speed but I do get over 100MPS. Give it a try.