Opticreep wrote:
(snip)

It's straight-through.

Although I may have a weird theory on why I'm having problems.
Apparently, my CAT5 cables weren't properly made. I noticed that pins
3 & 6 on the RJ45 didn't make a twisted pair. Instead, the techie who
installed the RJ45's for me made twisted pairs out of pins 3 & 4, and
then 5 & 6. This probably generated a lot of noise on signals going
through pins 3 and 6. I'm quite sure that category 5 standards state
that pins 3 & 6 make up a pair (and so does 4 & 5).

It isn't so much signal to noise, but the signal couples to the
other wires. Depending on which wires, it can make a big
difference in the signal at the other end.

This oversight probably didn't affect my short 0.5 meter cables too
much. But on a 25-meter cable, the signal-to-noise ratio might have
become too high. At least that's my theory.

But that still doesn't make sense. I don't think the signal-to-noise
ratio should be affected so drastically from this one little mistake.
And besides, why would this 24-ft CAT5e cable work between a DSL
straight to my PC, but *not* work between a router and a PC? Maybe it
has to do with signal strength or the different impedences, but
thinking too much makes my head hurt.

All routers I know of have 10baseT input and 10/100 output. That
makes a big difference in how well the cable works if mispaired.

-- glen