Linux Iptables: HowTo Block or Open HTTP/Web Service Port 80 & 443

by on July 11, 2005 · 13 comments· LAST UPDATED January 6, 2011

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By default Apache webserver listen on port 80 (http) and port 443 (https i.e. secure http). Apache webserver uses the TCP protocol to transfer information/data between server and browser. The default Iptables configuration does not allow inbound access to the HTTP (80) and HTTPS (443) ports used by the web server. This post explains how to allow inbound and outbound access to web services under Linux.

You can edit /etc/sysconfig/iptables file under RHEL / CentOS / Fedora Linux. Add the following lines, ensuring that they appear before the final LOG and DROP lines for the RH-Firewall-1-INPUT chain to open port 80 and 443:

 
-A RH-Firewall-1-INPUT -m state --state NEW -p tcp --dport 80 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -p tcp --dport 443 -j ACCEPT
 

Finally, restart the firewall:
# service iptables restart
If you've your own shell script, try:

 
/sbin/iptables -A INPUT -m state --state NEW -p tcp --dport 80 -j ACCEPT
/sbin/iptables -A INPUT -m state --state NEW -p tcp --dport 443 -j ACCEPT
 

Allow incoming http/web traffic at port 80

 
SERVER_IP="202.54.10.20"
iptables -A INPUT -p tcp -s 0/0 --sport 1024:65535 -d $SERVER_IP --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp -s $SERVER_IP --sport 80 -d 0/0 --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
 

Allow incoming https/secure web traffic at port 443

 
SERVER_IP="202.54.10.20"
iptables -A INPUT -p tcp -s 0/0 --sport 1024:65535 -d $SERVER_IP --dport 443 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -p tcp -s $SERVER_IP --sport 443 -d 0/0 --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
 

Allow outgoing http/web service traffic to port 80

 
SERVER_IP="202.54.10.20"
iptables -A OUTPUT -p tcp -s $SERVER_IP --sport 1024:65535 -d 0/0 --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp -s 0/0 --sport 80 -d $SERVER_IP --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
 

Allow outgoing https/secure web service traffic to port 443

 
SERVER_IP="202.54.10.20"
iptables -A OUTPUT -p tcp -s $SERVER_IP --sport 1024:65535 -d 0/0 --dport 443 -m state --state NEW,ESTABLISHED -j ACCEPT
iptables -A INPUT -p tcp -s 0/0 --sport 443 -d $SERVER_IP --dport 1024:65535 -m state --state ESTABLISHED -j ACCEPT
 
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{ 13 comments… read them below or add one }

1 Sunil Shrestha December 29, 2006 at 7:46 am

grate site

Reply

2 Uttam Shrestha Rana March 1, 2007 at 9:33 am

How to configure Squid server with bandwidth limitation for particular network ips?
If you response with the configuration, then it will be great help me if not also, from this site i have got lots of information. Thanks. Its a greate knowledge protal.

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3 Vasanth kumar August 2, 2007 at 9:51 pm

In windows how to block https site like Gmail

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4 kunal February 25, 2008 at 11:48 am

Script to block incoming HTTP request from an IP say after 20 continue requests.

Thanks in advance
–kunal

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5 kunal February 25, 2008 at 11:49 am

Just to add one more thing IP blocking should be done for certain period of time say 5 hrs and after unblock that IP.

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6 Liju July 4, 2008 at 3:39 pm

This would be much simple and better. There is no necessary to permit the oubound traffic to be opend and can be avoided.

# Allow incoming port 80 and 443 (http/s) traffic
/sbin/iptables -A INPUT -p tcp –dport 80 -m state –state NEW -j ACCEPT
/sbin/iptables -A INPUT -p tcp –dport 443 -m state –state NEW -j ACCEPT

Reply

7 Well... May 8, 2009 at 5:17 am

…you all forgot to mention that conntrack has to be enabled as well. Otherwise only the first packet of the connection is let in, but the “real” data is still blocked… ;-)

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8 Yogesh July 31, 2010 at 8:42 am

To block Gtalk, i want to set the restriction to this address:
216.239.37.125, 72.14.253.125, 72.14.217.189 and 209.85.137.125 on ports 20, 21, 80, 443, 5222 and 5223

How can I block these addresses to block Gtalk and https://mail.gmail.com request in transparent proxy.I am using the same script provided by nixcraft to configure Transparent proxy.

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9 pron September 21, 2010 at 6:38 pm

hello,

can you give opposite – i need example how to configure iptables for webserver, that need access to windows local network also.

thank you in advance!

Reply

10 shahadat December 4, 2011 at 4:06 am

hello sir,
how way bock https port number in the linux Ip table. Actually I wanted bock the browser by the https port way. like facebook.

thanks
Shahadat

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11 Chris D. December 23, 2011 at 9:39 am

I have open port 80 as you describe here but I cannot access my site from web.
I have also configure router to forward port 80 to the pc with the apache server.
Have you any idea what could be the problem?
Thanks in advance.

Reply

12 Yogesh April 18, 2012 at 11:21 am

Hi,
I am using squid proxy server in a non-transparent mode. mean everybody need to set the proxy in their browsers. These settings prevent my users to connect to any other port except 80.

But for some reason I have to grant my IT team to access some port specific software like sqlyog, eclips etc to a particular server IP address
To allow I do run this command.
iptables -t nat -A POSTROUTING -s 192.168.1.48 -p tcp -m state –state NEW,ESTABLISHED -j SNAT –to-source server_public_ip
But This command opens everything i.e gtalk, msn messenger, bit-torrents etc so I want to limit my users to make connection to required server only so that they can connect the MySQL server only using SQLYog etc.

I have two Interface on proxy server eth0 (Public Interface) eth1 (local interface)
local intyerface is connected to my local network only.

Please help

Reply

13 Yogesh April 19, 2012 at 10:55 am

Anyone have any idea how to do it ??

Pls help

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