Just got done doing some wiring work in the attic, and it turns out that the initial run of Cat 6 was too short, so I am using a coupler.

Now, is using one a bad idea in any way? Some people have said that you run the risk of corrupted data if you do. And will it limit speeds?

What is the length of the run? Do you have a cable tester? What are you going to use the network run for?

In most cases I doubt you will have a problem. If you were pushing gigabit ethernet in a data center, I'd re-run the drop.

Your more than likey fine unless the cable is like 250' long. Cat 5 will push 1000base-t so running cat 6 even with a couple should be fine.

It's a 50 ft. Cat 6 connected to a 15 ft. Cat 5e with a Cat 5e coupler.

I'm just using it for basic internet, so I assume everything should be alright.

I do intend to replace the coupler and wire with Cat 6 versions, since mixing cable types doesn't seem too sensible.

it ain't gonna hurt anything. your only wasting the money you spent on cat 6 cable though. but that's no different from anyone else who installs cat 6 cable anyway