The bucket effect: When bucket gets full, everything is dumped out and bucket begins refilling, where the bucket is the network connection/transmission. In effect you are able to reach the destination, but before the round-trip can occur, all communications appear to get severed. In this scenario, if other short requests(small packets) are getting through, like a web request for data, yet longer requests such as file transfers, SSH/RDP sessions, are dropping out, look for recent network. Don't assume something like a firewall or managed switch couldn't possibly be the culprit, just because you, yourself or team, didn't initiate a change request(Active/Ative? WTM?). Meh. Also don't assume everyone has already checked on these or any other obvious things. Force an acknowledgment by the group.
Funny quote during vendor site-visit:
"Before we make any changes we'll need to take a dump."I almost lost it :-P. Vendor was actually referring to a snapshot/backup of a database before acting upon it, in case a rollback is required.