ipset -N myBlackhole-4 hash:net family inet
ipset -N myBlackhole-6 hash:net family inet6
ipset -A myBlackhole-4 103.243.177.0/24
iptables -A INPUT -m set --match-set myBlackhole-4 src -j DROP
ip6tables -A INPUT -m set --match-set myBlackhole-6 src -j DROP