paul's blog

Following on from postfix - blocking spam before it enters the server i setup a whitelist and SPF filtering.

The whitelist will allow me to manually allow any mail servers to bypass the spf filtering and RBL(Real-time Blacklists) lists.

As you should know by now CentOS uses Yum to install and update packages but sometime you need packages that are not available as standard, one way to get these packages is to use 3rd party repositories which is what i do.

A note on CentOS packages

When i first setup the server part 1 and part 2 i used the basic setting for postfix but soon found that i could reduce the amount of spam and load on the server by rejecting it before accepting it, i will do this by forcing mail servers that wanna deliver mail to me to be configured correctly and by using a few RBL (Real-time Blacklists).

In this blog I'll try and explain what ipv6 is and how i setup the server to use it.

What is IPv6? IPv6 is pretty much the same as IPv4. IPv4 is what is primarily used on the internet today. The big difference is the size of the address. The address for IPv6 are 128 bits long vs 32 bits for IPv4. IPv6 also uses hex to express address where as IPv4 only uses numeric values so you will see numbers 0-9 and letters A-F in a IPv6 address.

As this box will be used for hosting websites i install Virtualmin GPL. It is a Webmin module for managing multiple virtual hosts through a single interface, Similar to Plesk or Cpanel. It supports the creation and management of Apache virtual hosts, BIND DNS domains, MySQL databases, and mailboxes and aliases with Sendmail or Postfix. It makes use of the existing Webmin modules for these servers, and so should work with any existing system configuration, rather than needing it's own mail server, web server and so on.

Now we got the basic setup done i install Webmin to make life a bit easier.

first login to server and become root, then i do

wget http://prdownloads.sourceforge.net/webadmin/webmin-1.500-1.noarch.rpm

this will download the webmin rpm (check if their is a newer version first)
then we install it

rpm -U webmin-1.500-1.noarch.rpm

Carrying on from Basic server setup - part 1 we will finish installing packages.

Now I install Postfix and Dovecot

yum install cyrus-sasl cyrus-sasl-devel cyrus-sasl-gssapi cyrus-sasl-md5 cyrus-sasl-plain postfix dovecot

Now i configure TLS and SMTP-AUTH

postconf -e 'smtpd_sasl_local_domain ='
postconf -e 'smtpd_sasl_auth_enable = yes'
postconf -e 'smtpd_sasl_security_options = noanonymous'
postconf -e 'broken_sasl_auth_clients = yes'

This is how i first setup my server so it has basic functions like Apache web server (SSL-capable), Postfix mail server with SMTP-AUTH and TLS, BIND DNS server, Proftpd FTP server, MySQL server, Dovecot POP3/IMAP, Quota, Firewall, etc. Most of this has setup is based off various different tutorials i've used.

As my server is hosted in a Data centre they install the base system (CentOS 5.x) for me but if you have physical access you can do this yourself, you just need to grab the 1x dvd or 6x cd images mirror list here

Well seeing as this blog is a way for me to document what i do to the servers i use i should start by giving some specs on the main server it self.

My main server is hosted by INX-Gaming at Bluesquare Datacentre, Maidenhead.
Its a self managed dedicated server with a 100mbit connection
Dell PowerEdge 860 1U rack mount
Intel Xeon Dual core CPU 3040
Ram 4GB (2x 2GB DDR2)
Hard drive sata 250GB
Its running Linux CentOS 5.4 with the PAE kernel.