TIL: Amazon Nat Gateway drops your connections after 5 mins idle

Yes, after many hours of head scratching, I found out that if you're inside an amazon VPC, and use a NAT gateway or a NAT instance as your internet gateway, silent connections for more than 5 minutes will be dropped, or, even "better", just silenced, but you won't notice anything, just silence.

For long streaming connections going 'mute' for maintenance, you won't recover automatically.