Solved

Is this a good start for iptables on a web server?

Posted on 2011-09-13
6
584 Views
Last Modified: 2012-08-13
Hello everyone,

For the past two days I've been looking into how to set up iptables for a linux machine that acts as a web server, processes email, and also needs FTP and SSH access. I'm wondering if what I have put together to set iptables is enough, and/or, going to impede the server's functions at all. It's a basic LAMP setup. I'm also wondering if the order of the rules is basically correct.

I think it's close, but my main concerns are PHP, MySQL, email and FTP running. Do PHP and MySQL communicate on the localhost level, or do other ports (3306) need to be added? Is there anything I've overlooked that should also be added?
Is sendmail in the INPUT necessary? (I couldn't figure that one out)

Putting together and editing from several resources online, this is what I've come up with:

#!/bin/bash
#
# iptables example configuration script
#
# Flush all current rules from iptables
#
 iptables -F
#
# Allow SSH connections on tcp port 22
# This is essential when working on remote servers via SSH to prevent locking yourself out of the system
#
 iptables -A INPUT -s 12.34.56.78 -p tcp --dport 22 -j ACCEPT
 iptables -A INPUT -s 98.76.54.0/24 -p tcp --dport 22 -j ACCEPT
#
# Set default policies for INPUT, FORWARD and OUTPUT chains
#
 iptables -P INPUT DROP
 iptables -P FORWARD DROP
 iptables -P OUTPUT ACCEPT
#
# Set access for localhost
#
 iptables -A INPUT -i lo -j ACCEPT
#
# Accept packets belonging to established and related connections
#
 iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
#
# FTP
 iptables -A INPUT -p tcp --dport 20:21 -j ACCEPT
#
# HTTP/Apache
 iptables -A INPUT -p tcp --dport 80 -j ACCEPT
#
# SSL/Apache
 iptables -A INPUT -p tcp --dport 443 -j ACCEPT
#
# POP3
 iptables -A INPUT -p tcp --dport 110 -j ACCEPT
#
# Sendmail
 iptables -A INPUT -p tcp --dport 25 -j ACCEPT
#
# DirectAdmin
 iptables -A INPUT -s 12.34.56.78 -p tcp --dport 2222 -j ACCEPT
 iptables -A INPUT -s 98.76.54.0/24 -p tcp --dport 2222 -j ACCEPT
#
# ICMP/Ping:
 iptables -A INPUT -p icmp -j ACCEPT
#
 iptables -A INPUT -j REJECT
 iptables -A FORWARD -j REJECT
#
# Save settings
#
 /sbin/service iptables save
#
# List rules
#
 iptables -L -v

Open in new window


Any assistance is greatly appreciated.

Thank you for your time.
0
Comment
Question by:mvtimes
6 Comments
 
LVL 5

Accepted Solution

by:
RizyDeWino earned 500 total points
Comment Utility
The settings look fine in general and you do need to have 25 port open if its running mail server as users will be connecting to this port to send email from their end, and also for server sending mail out the outbound port need to be opened as well. For ftp you will probably need to add a passive ports range to firewall and ftp configuration depending on your setup.
For MySQL if you would be allowing remote MySQL connections for your clients, then you will need to have 3306 opened for it as well.

But before checking iptables rules in more depth, I would like to ask that have you considered using CSF firewall instead ?  http://configserver.com/cp/csf.html  ,


Its best firewall for cPanel or DirectAdmin servers/vps in my opinion. Gives you lot of options/features, GUI management and makes overall firewall maintenance lot easier for you. So before you go a head with direct iptables rules management route, do check csf firewall, with all its cool features the additional advantage is that its free.
0
 

Author Comment

by:mvtimes
Comment Utility
I was just looking to use what was already there. I'm admining this machine remotely, and I'm not that versed in linux so, using what I already had seemed to be the easier/quicker way.

We have DirectAdmin control panel, so regarding CSF, it seems that running the install as laid out here, http://configserver.com/free/csf/install.txt would be all that I'd have to do, correct?
0
 
LVL 5

Expert Comment

by:RizyDeWino
Comment Utility
Yes that is correct , it will have all required port configurations added by default at end of installation steps given in this URL , you can further manage it from directadmin gui when required.
0
Highfive Gives IT Their Time Back

Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

 
LVL 5

Expert Comment

by:hvillanu
Comment Utility
Hi,
If iptables is a trouble for you try this: http://www.fwbuilder.org/
-regards-
0
 
LVL 3

Expert Comment

by:maxchow
Comment Utility
1. MySQL can work with pipe files, no 3306 needed, however, you can change the listening IP to 127.0.0.1 to prevent problem.
2. try change ssh and ftp to other port numbers if possible
3. change PermitRootLogin to no in /etc/ssh/sshd_config and use sudo all the time.
4. Firewall is not actually important, use netstat -lpn to see how many listening ports that you are not using and shutdown the service using chkconfig or update-rc
5. route your syslog to another machine if possible
0
 

Author Closing Comment

by:mvtimes
Comment Utility
Thank you. Even though I think I had the iptables rules correct, CSF made getting the firewall configured much easier, and LFD is helpful to have too.
0

Featured Post

Highfive + Dolby Voice = No More Audio Complaints!

Poor audio quality is one of the top reasons people don’t use video conferencing. Get the crispest, clearest audio powered by Dolby Voice in every meeting. Highfive and Dolby Voice deliver the best video conferencing and audio experience for every meeting and every room.

Join & Write a Comment

This is a guide to setting up a new WHM/cPanel Server to be used for web hosting accounts. It is intended for web hosting company administrators and dedicated server owners. For under $99 per month (considering normal rate of Big Data Cetnters like …
One of the typical problems I have experienced is when you have to move a web server from one hosting site to another. You normally prepare all on the new host, transfer the site, change DNS and cross your fingers hoping all will be ok on new server…
This tutorial demonstrates a quick way of adding group price to multiple Magento products.
This video explains how to create simple products associated to Magento configurable product and offers fast way of their generation with Store Manager for Magento tool.

762 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

6 Experts available now in Live!

Get 1:1 Help Now