News Category
Hot Article
  1. Centos7 closes and restarts the system firewall and opens firewall ports
  2. How IID server uses Xshell to connect to Linux (centos) server
  3. BT panel forgets the background login URL, and the solution to the security entrance verification failure
  4. What to do if a cp: omitting directory error occurs in Linux (detailed solution)
  5. The php domain name points to ip, how to use the specified ip address to access a server in the url request domain name in curl mode
  6. Error connecting to MySQL: Cant connect to MySQL server (10060)
Popular Tags

How to block foreign IP access on Linux server?

Log in to the Linux cloud server remotely through SSH, and run the following command statement to obtain the domestic IP network segment, which will be saved as /root/china_ip.txt

wget -q --timeout=60 -O- 'http://ftp.apnic.net/apnic/stats/apnic/delegated-apnic-latest' | awk -F\| '/CN\|ipv4/ { printf("%s/%d\n", $4, 32-log($5)/log(2)) }' > /root/china_ip.txt

Save the script below as /root/allcn.sh.

mmode=$1
CNIP="/root/china_ip.txt"
gen_iplist() {
        cat <<-EOF
                $(cat ${CNIP:=/dev/null} 2>/dev/null)
EOF
}

flush_r() {
iptables  -F ALLCNRULE 2>/dev/null
iptables -D INPUT -p tcp -j ALLCNRULE 2>/dev/null
iptables  -X ALLCNRULE 2>/dev/null
ipset -X allcn 2>/dev/null
}

mstart() {
ipset create allcn hash:net 2>/dev/null
ipset -! -R <<-EOF 
$(gen_iplist | sed -e "s/^/add allcn /")
EOF

iptables -N ALLCNRULE 
iptables -I INPUT -p tcp -j ALLCNRULE 
iptables -A ALLCNRULE -s 127.0.0.0/8 -j RETURN
iptables -A ALLCNRULE -s 169.254.0.0/16 -j RETURN
iptables -A ALLCNRULE -s 224.0.0.0/4 -j RETURN
iptables -A ALLCNRULE -s 255.255.255.255 -j RETURN
iptables -A ALLCNRULE -m set --match-set allcn  src -j RETURN 
iptables -A ALLCNRULE -p tcp -j DROP 
}

if [ "$mmode" == "stop" ] ;then
flush_r
exit 0
fi

flush_r
sleep 1
mstart

Make the script executable.

chmod +x  allcn.sh

 

Execute the following command to start blocking foreign IP access.

/root/allcn.sh

Execute the following command to stop blocking foreign IP access.

/root/allcn.sh stop

related topic

Prev: How to modify the remote port in CentOS 7 and 8
Next: Error connecting to MySQL: Cant connect to MySQL server (10060)

Online Service

Live Chat