Open range ports via ufw or iptables
For UFW
ufw allow from any to any port 4000:4020 proto tcp
For iptables
iptables -A tableName -p tcp --match multiport --dports port1,port2 -j ACCEPT
iptables -A tableName -p udp --match multiport --dports port1,port2 -j DROP
iptables -A tableName -p protocol --match multiport --dports portRange1:PortRange2 -j ACCEPT
iptables -A tableName -p tcp --match multiport --sports port1,port2 -j ACCEPT
iptables -A tableName -p udp --match multiport --sports port1,port2 -j DROP
iptables -A tableName -p protocol --match multiport --sports portRange1:PortRange2 -j ACCEPT
Written on March 15, 2017