[olug] How can I sever IPtables established connections for only certain IPs?

[Ben Hollingsworth]

I have a somewhat complex IPtables setup (configured via fwbuilder) that 
protects my home network. My firewall box runs Ubuntu server 20.04. At a 
certain hour each night, I block a handful of IPs that belong to my 
children's devices so that they can't use them all night. I do this by 
keeping two separate IPtables configs and using cron to install the 
appropriate one at the appropriate time.

This works fine for blocking new connections, but I've found that any 
connections that happen to be open when the new config is loaded will 
continue to stay open. My kids have figured that out as well.

The problem comes from this line, which exists in both configs, and 
keeps related connections open across my reload:

$IPTABLES -A FORWARD -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT

Is there any way that I can turn off connection tracking for only 
certain IPs? I'd really rather that open connections for authorized IPs 
not get interrupted, but I can live with that if I must.

-- 
*Ben "Obi-Wan" Hollingsworth* obiwan at jedi.com www.Jedi.com 
<http://www.jedi.com>
The stuff of earth competes for the allegiance I owe only to the
Giver of all good things, so if I stand, let me stand on the
promise that You will pull me through. /-- Rich Mullins/