iptables-restore < /etc/sysconfig/iptables
service iptables save
iptables -A OUTPUT -d 127.0.0.1/32 -j ACCEPT
iptables -A OUTPUT -d 10.0.0.0/8 -j ACCEPT
iptables -A OUTPUT -d 52.119.0.0/16 -j ACCEPT
iptables -A OUTPUT -d 52.94.0.0/16 -j ACCEPT
iptables -A OUTPUT -d 169.254.0.0/16 -j ACCEPT
iptables -A OUTPUT -j DROP
##to delete a rule:
iptables -D OUTPUT -j DROP
## ORDER IS IMPORTANT!!!! so a easier way is to edit /etc/sysconfig/iptables and restart service.
systemctl start iptables
systemctl enable iptables
##command used to block ldap connections (all other rules were deleted while running this one)
while (true); do iptables -A OUTPUT -j REJECT -d 10.0.20.171; sleep 6; iptables -D OUTPUT -j REJECT -d 10.0.20.171; sleep 6; iptables -A OUTPUT -j REJECT -d 10.0.20.172; sleep 6; iptables -D OUTPUT -j REJECT -d 10.0.20.172; done