On Mon, 8 Aug 2016 at 03:15, Brian <a...@cityscape.co.uk> wrote: > On Sun 07 Aug 2016 at 03:32:00 +0000, Mark Fletcher wrote: > > > In the end I got what I needed by using Lars' pointer of the iptables > > extensions. I copied the iptables systemd service unit from my LFS box to > > the machine in question, and then created a script in > /etc/systemd/scripts > > that first sets the iptables output chain policy to DROP, then adds these > > rules: > > > > iptables -A OUTPUT -m time --starttime 00:00 --stoptime 12:00 -j ACCEPT > > iptables -A OUTPUT -d 192.168.11.0/24 -j ACCEPT > > Would being able to alter UTC from the BIOS be reckoned to be a strong > technical skill? And, more to the point, would it work in your situation? > > I don't think it would since ntp would just change it back on boot.
Now, telling Linux that the bios clock isn't utc -- now that would eff things up. But if he gets the access he'd need to do that all bets are off anyway as he could just change the firewall rules. Mark