Background: the Uverse guy gave me a big spool of cat5e "in case I needed it later" which was great. Here is the setup:
My uverse router is in my house. One cable goes from it down into the crawlspace, into a 10/100 switch which feeds various ethernet ports in the rooms in my house.
One cable however, runs out to the shed behind my house (underground cat5e) and for the last few years I've been happy to plug into the switch in the shed (office) when I've been working.
I also, occasionally would bring the 2nd Uverse box out there to the shed, and plug it into the switch in the shed. Worked fine; I could watch live TV, etc. all over the ethernet. (I wish I could find out how much bandwidth that device actually needs).
So to summarize:
Uverse in house House---------> Shed # works fine. switch in shed
BUT my brother lives next door and he wondered if every now and then, on a big game day, he could borrow the 2nd uverse box to watch football in his house. He lives right next door, our houses almost touch. The most unobtrusive path to his house was from the shed, so I used the cat5e cable left by the uverse guy to make a run from the switch in my shed to his living room.
using the primitive cable tester I have (that simply lights up to indicate each pair is functioning) it seems fine. But I can't acquire an ip when I plug the run into my macbook. Even when I hard assign an ip that should work within the uverse subnet, it doesn't work.
If I walk back to the shed and plug into the switch with a short station cable right at the desk, it works fine. acquires an IP from the uverse router, works great.
I'm mystified that the cable tester was green, but nothing is working. What am I doing wrong?
What can I do to narrow down the problem? I haven't gotten into the nitty gritty of this stuff for a long time.