1fe-Tx vs fe1-Fx

I have a Cisco3640 with 2 fast ethernet cards in it.

One of the ethernet ports is dropping packets,
(ie. losing pings).

On the "show interface fast" command it says,
"100BaseTX/FX".

But when I look to buy a replacement 100-Mb card,
I appear to have 2 options:

(1) NM-1FE-TX

(2) NM-1FE-FX

What are the differences?

Which one do I currently have,(if it lists both on the
running configs)?

And if I upgrade,(3700, 3800, etc....), would one be
better then the other,(for being able to be used in a
newer model of router)?

Or should I be looking at a "NM-2FE" card?

 

pinging of the device itself? The device will drop pings if it
is under heavy load, and in any case [I believe] has an icmp throttle
rate (10 per second comes to mind, but could easily be wrong.)

Check also for duplex mismatches.

TX is RJ45 style connector, FX is fibre connector. But you
can't buy NM-1FE-FX anymore: the new part is NM-1FE-FX-V2

http://www.cisco.com/en/US/products/hw/routers/ps274/products_data_sheet09186a0080091b89.html

Look through the list at the URL above. There isn't any card for
that router series which provides multiple fast ethernets directly.
If memory serves me, the way to get multiple fast ethernets on that
line is to get one of the NM-*2W (e.g, NM-1E2W) and then fill the two
WIC slots with fast ethernet WICs. You have to plan the performance
(and budget!) carefully if you take this approach.

 

TX and FX is different

Buy NM-2FE-2W will do the job