In order to block an IP on your Linux server you need to use iptables tools (administration tool for IPv4 packet filtering and NAT) and netfilter firewall. First you need to log into shell as root user. To block an IP address you need to type the iptables command as follows:
Syntax to block an IP address under Linux
Code:
iptables -A INPUT -s IP-ADDRESS -j DROP
Replace IP-ADDRESS with your actual IP address. For example, if you wish to block an ip address 65.55.44.100 for whatever reason then type the command as follows:
Code:
# iptables -A INPUT -s 65.55.44.100 -j DROP
If you have IP tables firewall script, add the above rule to your script.
If you just want to block access to one port from an ip 65.55.44.100 to port 25 then type command:
Code:
# iptables -A INPUT -s 65.55.44.100 -p tcp --destination-port 25 -j DROP
The above rule will drop all packets coming from IP 65.55.44.100 to port mail server port 25.
CentOS / RHEL / Fedora Block An IP And Save It To Config File
Type the following two command:
Code:
# iptables -A INPUT -s 65.55.44.100 -j DROP
# service iptables save
Moderator's Comments:
Use code tags, thanks.
Last edited by zaxxon; 11-06-2015 at 03:55 AM..
Reason: code tags
I have 2 LAN's, seperated by a firewall, running iptables on it.
I want only allow ftp access from one to the other LAN.
Server 1 in LAN 1 should have ftp access to Server 2 in LAN 2
Server 2 in LAN 2 should not have ftp access to Server 1 in LAN 1.
Can someone tell me how to set up the... (5 Replies)
Hi
I am looking to block an incomming IP for all the subnet in lab area. Only single Ip from Lab should be access to this incomming IP.
Block IP=10.20.50.xx
Subnet=10.30.40.xx
............................
...........................
Subnet=10.40.50.xx
can anyone explain how to do... (2 Replies)
Discussion started by: boby.kumar
2 Replies
LEARN ABOUT REDHAT
ip6tables-save
IPTABLES-SAVE(8) iptables 1.6.1 IPTABLES-SAVE(8)NAME
iptables-save -- dump iptables rules to stdout
ip6tables-save -- dump iptables rules to stdout
SYNOPSIS
iptables-save [-M modprobe] [-c] [-t table]
ip6tables-save [-M modprobe] [-c] [-t table]
DESCRIPTION
iptables-save and ip6tables-save are used to dump the contents of IP or IPv6 Table in easily parseable format to STDOUT. Use I/O-redirect-
ion provided by your shell to write to a file.
-M, --modprobe modprobe_program
Specify the path to the modprobe program. By default, iptables-save will inspect /proc/sys/kernel/modprobe to determine the exe-
cutable's path.
-c, --counters
include the current values of all packet and byte counters in the output
-t, --table tablename
restrict output to only one table. If not specified, output includes all available tables.
BUGS
None known as of iptables-1.2.1 release
AUTHORS
Harald Welte <laforge@gnumonks.org>
Rusty Russell <rusty@rustcorp.com.au>
Andras Kis-Szabo <kisza@sch.bme.hu> contributed ip6tables-save.
SEE ALSO iptables-apply(8),iptables-restore(8), iptables(8)
The iptables-HOWTO, which details more iptables usage, the NAT-HOWTO, which details NAT, and the netfilter-hacking-HOWTO which details the
internals.
iptables 1.6.1 IPTABLES-SAVE(8)
11-06-2015
