Of course in this case dhcp server is not running all the time but is only started after interface comes up.
the biggest struggling from my side was to find the right place for startup command

iface eth0 inet static
address ...
netmask ...
gateway ...
up run_my_upscript
down run_my_downscript

this is good idea to make stuff understandable later
I will test this approach some when

Hmm, there is no directory /lib/dhcpcd/dhcpcd-hooks in my pi :/ I created it and placed sample file there (giving it +x ) but nothing happened .. Aren't you using dhcp for client not server in your example ? Looks I found the place. I added to file /etc/ifplugd/ifplugd.action under case up : case "$...

actually I placed additional script to /etc/network/if-up.d :
#! /bin/sh
logger abc
and chmod +x , but it does not execute when I plug the cable :/

Hi! Pi is controlling some stuff, normally it is not connected to any network. Time to time there is need to do some maintenance or take log files, so a laptop is connected by straight patch cord to eth0 of pi. I've installed ISC DHCP server in order to have "plug and play" - DHCP server from Pi giv...