Hi my iptables firewall.

iptables -F
iptables -X
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -A INPUT -s 195.244.34.17 -j ACCEPT
iptables -A INPUT -s 208.167.255.11 -j ACCEPT
iptables -A INPUT -s 208.167.255.12 -j ACCEPT
iptables -A INPUT -s 208.167.255.13 -j ACCEPT
iptables -A INPUT -s 208.167.241.182 -j ACCEPT
iptables -A INPUT -s 198.41.204.52 -j ACCEPT
iptables -A INPUT -s 208.167.241.190 -j ACCEPT
iptables -A INPUT -s 208.167.241.183 -j ACCEPT
iptables -A INPUT -s 208.167.241.185 -j ACCEPT
iptables -A INPUT -s 208.167.241.186 -j ACCEPT
iptables -A INPUT -s 208.167.241.189 -j ACCEPT
iptables -A INPUT -s 108.61.78.147 -j ACCEPT
iptables -A INPUT -s 108.61.78.148 -j ACCEPT
iptables -A INPUT -s 108.61.78.149 -j ACCEPT
iptables -A INPUT -s 108.61.78.150 -j ACCEPT
iptables -A INPUT -s 176.33.133.150 -j ACCEPT
iptables -A INPUT -p udp -m length --length 0:40 -j DROP

Don't scanner server.
iptables -A INPUT -p udp -m length --length 0:40 -j DROP delete

Scanner server. No Problem.

Plase help me. Give scanner gametracker IP.