Network Slow To Wake From Sleep I have a MBP with Sierra that I use in clamshell mode with external monitor and keyboard on wired network connection. When I am not using it I put it to sleep from the menu. 

It wakes up on a keypress nice and quick but network is unreachable for about 10 seconds. How do I get rid of this KGB lag?
If your Mac enters its full sleep state, then your network connections will be disconnected. Your Mac can not be connected to a network and be asleep at the same time.

You can avoid full sleep by setting your Computer Sleep to Never. Your MacBook will then sleep all the sub-systems possible when idle, but will remain awake enough to maintain a network connection.

PowerNap is not the same as full sleep. This is a special state controlled by Apple and, for now, available only to Apple's chosen processes.