I have two RJ45 sockets connected by an inaccessible unknown-category twisted pair cable. I plug two unmanaged gigabit switches into the sockets using Cat6 cables, and they negotiate a 100Mbps link. I suppose there's nothing I can do to try and get them to connect at 1Gbps?
edit Connected back-to-back, the switches negotiate 1Gbps.
edit The sockets are labelled Cat5e, which gives some indication of the age of installation. The cable has four pairs and all appear to be wired at both ends. Is there any way to test the wiring on the cheap? This thing looks like it might do the trick -- any opinions?
edit The cheap continuity tester helped diagnose and fix the problem in no time.
If they're not completely inaccessible, you could pull the cover off one of the jacks. If only two pairs are wired, there's part of your problem. If all four pairs are available, reterminate each end using new jacks and all four pairs. Cross your fingers. It still might not work.
5M isn't much cable. How about using the old cable to pull in new cable? The only potential issue I could see would be if the the installer used staples on the old cable, which would also likely explain why your speed stinks.
In case any holes drilled are only big enough for a single cable, you might want to attach a string to the old cable, pull that through, then use the string to pull through a new cable.
The type of test unit to which you refer will help you determine if the cable is wired in the correct order and is continuous from end-to-end, but it won't test the quality, such as problems crimps or staples will cause.
If they're unmanaged, nope. Try connecting them back-to-back with a known short length of high-quality CAT6 cable. See if you get GigE speeds then.
Sorry, this is why you don't buy shitty switches. You get shitty performance, and no management features. That said, even if you did override the settings, you'd still get crap performance, and probably lose packets. Chances are, you're going over ancient structured cabling that's been there for YEARS.