I know we had troubles connecting to the robot in our first event, I suspect because of mDNS issues. Our DS would connect, but networktables wouldn't. Switched to static IPs +
dashboard hack, no issues.
The reason I say mDNS is that it seems like once it gets resolved, it doesn't seem to actually cache the values. A second query to a name takes just as long as the first, and it's often a few seconds. I haven't done any deep analysis on it, but I'm tired of it so I just use static IPs.