[mhaeberli]

Mark,
Thank you for the advice. It turns out to be a bit more subtle than I first indicated.
It probably is related to TCP / IP settings. I accidentally found out that one other machine on the network _can_ communicate. The machine that failed had been working, but then failed for no apparent reason in the middle of the afternoon.
I also learned that, if _one_ machine has the Driver Station running, then no other machines can connect as Driver Station. This shouldn't surprise me, in hindsight.
Amusingly enough, the machine that fails can still upload code and FTP to the cRIO.
Best,
Martin