Loading ...Linux Iptables block incoming access to selected or specific ip address
Sometime it is necessary to block incoming connection or traffic from specific remote host. iptables is administration tool for IPv4 packet filtering and NAT under Linux kernel. Following tip will help you to block attacker or spammers IP address.
How do I block specific incoming ip address?
Following iptable rule will drop incoming connection from host/IP 202.54.20.22:
iptables -A INPUT -s 202.54.20.22 -j DROP iptables -A OUTPUT -d 202.54.20.22 -j DROP
A simple shell script to block lots of IP address
If you have lots of IP address use the following shell script:
A) Create a text file:
# vi /root/ip.blocked
Now append IP address:
# Ip address block file 202.54.20.22 202.54.20.1/24 #65.66.36.87
B) Create a script as follows or add following script line to existing iptables shell script:
BLOCKDB=”/root/ip.blocked” IPS=$(grep -Ev "^#" $BLOCKDB) for i in $IPS do iptables -A INPUT -s $i -j DROP iptables -A OUTPUT -d $i -j DROP done
C) Save and close the file.
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- How do I Drop or block attackers IP with null routes?
- Linux Iptables block all network traffic
- Linux Iptables block outgoing access to selected or specific ip address
- Tutorial simple Linux firewall configuration using NetFilter / iptables
- How to: Linux Iptables block common attacks
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Tags: block_incoming_connection_ip, block_ip_address_shell_script, Iptables, iptables_command, linux_block_ip_address
Thanks for the script!
I’m using it to block some traffic that was comment spam in my wordpress installation. Akismet was catching the spam itself, but now I’m blocking a handful of IPs at the firewall and don’t have to moderate as much garbage!
Much appreciated!
Dave.
D.E.R. Management, Inc - IT Project Management consulting
Cool, I’ve been running my own custom drop list I have honed over the years. Too much hacking. I block international access to domestic business servers whenever possible. I’m tired of those log files filled up with password guessing Asia. It works fantastic if one does not need access to international.
My blockiplist is text exactly like yours, but my script is different and I can’t recall why I did it this way, I hope it’s right, but it seems to work.
————
for i in `cat /etc/blockiplist|grep -v “#”`
do
ADDR=$i
/sbin/iptables -t filter -I INPUT -s $ADDR -j DROP
/sbin/iptables -t filter -I OUTPUT -s $ADDR -j DROP
/sbin/iptables -t filter -I FORWARD -s $ADDR -j DROP
/sbin/iptables -t filter -I INPUT -d $ADDR -j REJECT
/sbin/iptables -t filter -I OUTPUT -d $ADDR -j REJECT
/sbin/iptables -t filter -I FORWARD -d $ADDR -j REJECT
echo “Block ALL INPUT from ” $ADDR ” net DROPPED.”
done
—————–
i can not connect a linux system from a squid proxy server for internet uses than what will be do