Error 54 Unplugged Cable

[JW-JnJ]

I have a quad port NI PCIe-8235 that I'm using for UDP communication. We have the UUT which has 4 UDP ports and can enable/disable them on command. Ideally, I want to open a UDP connection and wait for any incomming traffic. Instead, some of the cards receive a Error 54.

After a lot of experimentation, I've noticed that if the card has been plugged in at any point, I don't get this error.

If I disable, then enable the network card while unplugged, I receive the error again.

If I plug the cable in, and unplug it, I don't receive the error on any UDP opens.

Normally, I would loop until I don't receive the error. However, this error also appear to detect wrong IP addresses, which I would consider a valid error.

My assumptions are:

I'm missing something blatantly stupid

or

These cards can get into a state that windows either forgets they're there, or doesn't allow connections. Hopefully I can circumvent.

or

Not allowing a connection is valid, and plugging/unplugging the cable tricks windows. Allowing me to cheat.

[JW-JnJ]

Well, I've verified that this happens on another network card (Realtek) and another machine (Win7).

I'm starting to think this had to do with how windows handles network cards.

[Wee-Bey · Accepted solution]

It might also depend on whether you're set for DHCP or not; you might be losing the IP address because of that. But yeah, it sounds like more of a Windows+ethernet cards behavior.

[JW-JnJ]

I gave up on delving into windows behavior and just started looping until no error occured on UDP open.

Thanks for the help.