sudo iptables -F
iptables -P INPUT DROP
iptables -P OUTPUT ACCEPT
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -s 207.253.220/22,216.113.0.0/22 -p tcp --dport 27015 -j ACCEPT
iptables -A INPUT -s 207.253.220/22,216.113.0.0/22 -p tcp --dport 27016 -j ACCEPT
iptables -A INPUT -p tcp --dport 27025 -j ACCEPT
iptables -A INPUT -s 207.253.222.192/26,10.1.99.0/24 -p tcp --dport 22 -j ACCEPT

#ACCEPT PINGS
iptables -A INPUT -p icmp -m icmp --icmp-type 3 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p icmp -m icmp --icmp-type 8 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p icmp -m icmp --icmp-type 11 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p icmp -m icmp --icmp-type 30 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT

/sbin/iptables-save