I've seen this as well. I have a case open with TB right now for it. What I was able to narrow it down to was if you lose link on the CS side of the processor that is what breaks the TCP/IP client. I was able to reproduce it everytime that way. I wrote 2 dummy demo programs and sent it in, one with a TCP Client and another with a TCP Server and took a video of it failing and a software reset/hardware reset fixing it.
I've never seen this on a 3 Series, only 4 Series, but I can certianly adapt my program to test it over on a 3 series as well. At home I have devices on CS that I'm using a TCP Client for communication and after switch reboots, switch firmware upgrades, power cycles, etc I've never found the devices to not properly reconnect.
I just checked my case and no updates since April 1st when they said they would mock up my programs and get back to me.
