In my opinion a got OS should never connect to the Internet or open ports at start.
We are not by Windos.

Other hand, it is practically when the Computer are ready conneted to the network and other people need cups or avahi.
The nonetwork cheatcode disable the network complett (but not avahi) and i am to lazy to reactivate the network after start.
For this reason here my suggestions:
a cheatcode called 'nonws' for 'no network service' instad of nonetwork
so you can disable services specific.
see the description:
nonws=service1;service2;..
... nonws = no network service
It disable some networkservices that are enable by default.
Services:
dhcp = dhcp
nm = NetworkManager
bt = bleutooth
avahi = avahi
cups = cups
all = similar to dhcp;nm;bt;avahi;cups
for example: nonws=bt;avahi;cups
Bleutooth avahi and cups will not start at booting, but dhcp and the NetworkManager.
Here a initrd for i486. The linuxrc with the changing code are inside.
Then i have build a simple script called nwservice <service> <on|off>. This can be enable or disable the services after booting.
At this draft i have ipv6 disregarded.
How can i prevent the loading of the ipv6 module. And how can i enable or disable ipv6 ?