Virtualmin is a powerful and flexible web hosting control panel for Linux and UNIX systems based on the well-known Open Source web-based systems management GUI, Webmin. Manage your virtual domains, mailboxes, databases, applications, and the entire server, from one comprehensive and friendly interface.

I recommend using Virtualmin; it made my life so EASY!, managing mail accounts, FTP, websites, Nginx, firewall… everything!.

But like every tool, it doesn’t cover everything. And that’s the idea of this guide. Yes, I just made your life way more comfortable! But how about the “under the hood side”?.

Installing Virtualmin and ntpdate:

wget https://software.virtualmin.com/gpl/scripts/install.sh
chmod 755 *
./install.sh
apt-get install ntpdate

Configuring Virtualmin:

The firewall:

If you want some sort of security and active connections to your ftp, you’ll need:

modprobe ip_conntrack_ftp
echo "IPTABLES_MODULES="ip_conntrack_ftp"" >> /etc/sysconfig/iptables-config

Getting your server “secure”

➜  ~ cat iptables.save 
# Generated by iptables-save v1.4.14 on Mon Jun  6 02:31:37 2016
*filter
:INPUT DROP [19:1020]
:FORWARD ACCEPT [513:37370]
:OUTPUT ACCEPT [6333:10196027]
:LDAP - [0:0]
:fail2ban-default - [0:0]
:fail2ban-ssh - [0:0]
-A INPUT -p tcp -m multiport --dports 22 -j fail2ban-ssh
-A INPUT -p tcp -m multiport --dports 22 -j fail2ban-ssh
-A INPUT -p tcp -m tcp --dport 22 -j fail2ban-default
-A INPUT -p tcp -m multiport --dports 22 -j fail2ban-ssh
-A INPUT -p tcp -m tcp --dport 389 -j LDAP
-A INPUT -p udp -m udp --dport 161 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 25565 -j ACCEPT
-A INPUT -p udp -m udp --dport 25565 -j ACCEPT
-A INPUT -s 10.254.3.0/24 -j ACCEPT
-A INPUT ! -i eth0 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 4949 -j ACCEPT
-A INPUT -p udp -m udp --dport 1196 -j ACCEPT
-A INPUT -p tcp -m tcp --tcp-flags ACK ACK -j ACCEPT
-A INPUT -m state --state ESTABLISHED -j ACCEPT
-A INPUT -m state --state RELATED -j ACCEPT
-A INPUT -p udp -m udp --sport 53 --dport 1024:65535 -j ACCEPT
-A INPUT -p icmp -m icmp --icmp-type 0 -j ACCEPT
-A INPUT -p icmp -m icmp --icmp-type 3 -j ACCEPT
-A INPUT -p icmp -m icmp --icmp-type 4 -j ACCEPT
-A INPUT -p icmp -m icmp --icmp-type 11 -j ACCEPT
-A INPUT -p icmp -m icmp --icmp-type 12 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 113 -j ACCEPT
-A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 53 -j ACCEPT
-A INPUT -p udp -m udp --dport 53 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 443 -j ACCEPT
-A INPUT -p tcp -m tcp -m multiport --dports 25,587 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 20:21 -j ACCEPT
-A INPUT -p tcp -m tcp -m multiport --dports 110,995 -j ACCEPT
-A INPUT -p tcp -m tcp -m multiport --dports 143,220,993 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 10000:10010 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 20000 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 3001 -j ACCEPT
-A LDAP -s 206.72.202.59/32 -j ACCEPT
-A LDAP -s 66.45.250.235/32 -j ACCEPT
-A LDAP -s 206.72.192.67/32 -j ACCEPT
-A LDAP -s 10.254.3.0/24 -j ACCEPT
-A LDAP -s 10.254.4.0/24 -j ACCEPT
-A LDAP -p tcp -m tcp --dport 3001 -j ACCEPT
-A fail2ban-default -j RETURN
-A fail2ban-ssh -s 222.186.21.217/32 -j DROP
-A fail2ban-ssh -j RETURN
-A fail2ban-ssh -j RETURN
-A fail2ban-ssh -j RETURN
COMMIT
# Completed on Mon Jun  6 02:31:37 2016
# Generated by iptables-save v1.4.14 on Mon Jun  6 02:31:37 2016
*mangle
:PREROUTING ACCEPT [49100981:39900927740]
:INPUT ACCEPT [47328481:39740284733]
:FORWARD ACCEPT [1408050:121664223]
:OUTPUT ACCEPT [32033396:88711307234]
:POSTROUTING ACCEPT [33441446:88832971457]
COMMIT
# Completed on Mon Jun  6 02:31:37 2016
# Generated by iptables-save v1.4.14 on Mon Jun  6 02:31:37 2016
*nat
:PREROUTING ACCEPT [1273587:85952983]
:INPUT ACCEPT [1201232:81100796]
:OUTPUT ACCEPT [587430:41574154]
:POSTROUTING ACCEPT [1110814:78989544]
-A PREROUTING -d 66.45.250.236/32 -j DNAT --to-destination 10.254.3.2
-A POSTROUTING -s 10.254.3.0/24 -j SNAT --to-source 66.45.250.236
COMMIT
# Completed on Mon Jun  6 02:31:37 2016

Configuring postfix:

General setup:

# See /usr/share/postfix/main.cf.dist for a commented, more complete version
 
 
# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname
 
smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
biff = no
 
# appending .domain is the MUA's job.
append_dot_mydomain = no
 
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
 
readme_directory = no
 
# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
 
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
 
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
# Add the networks used by you, that are safe.
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_command = /usr/bin/procmail-wrapper -o -a $DOMAIN -d $LOGNAME
mailbox_size_limit = 0
recipient_delimiter = +
virtual_alias_maps = hash:/etc/postfix/virtual
sender_bcc_maps = hash:/etc/postfix/bcc
sender_dependent_default_transport_maps = hash:/etc/postfix/dependent
home_mailbox = Maildir/
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions = permit_mynetworks permit_sasl_authenticated reject_unauth_destination check_policy_service inet:127.0.0.1:10023
allow_percent_hack = no
# Allow 40 MB message size.
message_size_limit = 40000000

Master Configuration (master.cf)

#
# Postfix master process configuration file.  For details on the format
# of the file, see the master(5) manual page (command: "man 5 master").
#
# Do not forget to execute "postfix reload" after editing this file.
#
# ==========================================================================
# service type  private unpriv  chroot  wakeup  maxproc command + args
#               (yes)   (yes)   (yes)   (never) (100)
# ==========================================================================
smtp    inet    n       -       -       -       -       smtpd -o smtpd_sasl_auth_enable=yes
#smtp      inet  n       -       -       -       1       postscreen
#smtpd     pass  -       -       -       -       -       smtpd
#dnsblog   unix  -       -       -       -       0       dnsblog
#tlsproxy  unix  -       -       -       -       0       tlsproxy
#submission inet n       -       -       -       -       smtpd
#  -o syslog_name=postfix/submission
#  -o smtpd_tls_security_level=encrypt
#  -o smtpd_sasl_auth_enable=yes
#  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
#  -o milter_macro_daemon_name=ORIGINATING
#smtps     inet  n       -       -       -       -       smtpd
#  -o syslog_name=postfix/smtps
#  -o smtpd_tls_wrappermode=yes
#  -o smtpd_sasl_auth_enable=yes
#  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
#  -o milter_macro_daemon_name=ORIGINATING
#628       inet  n       -       -       -       -       qmqpd
pickup    fifo  n       -       -       60      1       pickup
cleanup   unix  n       -       -       -       0       cleanup
qmgr      fifo  n       -       n       300     1       qmgr
#qmgr     fifo  n       -       n       300     1       oqmgr
tlsmgr    unix  -       -       -       1000?   1       tlsmgr
rewrite   unix  -       -       -       -       -       trivial-rewrite
bounce    unix  -       -       -       -       0       bounce
defer     unix  -       -       -       -       0       bounce
trace     unix  -       -       -       -       0       bounce
verify    unix  -       -       -       -       1       verify
flush     unix  n       -       -       1000?   0       flush
proxymap  unix  -       -       n       -       -       proxymap
proxywrite unix -       -       n       -       1       proxymap
smtp      unix  -       -       -       -       -       smtp
relay     unix  -       -       -       -       -       smtp
#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq     unix  n       -       -       -       -       showq
error     unix  -       -       -       -       -       error
retry     unix  -       -       -       -       -       error
discard   unix  -       -       -       -       -       discard
local     unix  -       n       n       -       -       local
virtual   unix  -       n       n       -       -       virtual
lmtp      unix  -       -       -       -       -       lmtp
anvil     unix  -       -       -       -       1       anvil
scache    unix  -       -       -       -       1       scache
#
# ====================================================================
# Interfaces to non-Postfix software. Be sure to examine the manual
# pages of the non-Postfix software to find out what options it wants.
#
# Many of the following services use the Postfix pipe(8) delivery
# agent.  See the pipe(8) man page for information about ${recipient}
# and other message envelope options.
# ====================================================================
#
# maildrop. See the Postfix MAILDROP_README file for details.
# Also specify in main.cf: maildrop_destination_recipient_limit=1
#
maildrop  unix  -       n       n       -       -       pipe
  flags=DRhu user=vmail argv=/usr/bin/maildrop -d ${recipient}
#
# ====================================================================
#
# Recent Cyrus versions can use the existing "lmtp" master.cf entry.
#
# Specify in cyrus.conf:
#   lmtp    cmd="lmtpd -a" listen="localhost:lmtp" proto=tcp4
#
# Specify in main.cf one or more of the following:
#  mailbox_transport = lmtp:inet:localhost
#  virtual_transport = lmtp:inet:localhost
#
# ====================================================================
#
# Cyrus 2.1.5 (Amos Gouaux)
# Also specify in main.cf: cyrus_destination_recipient_limit=1
#
#cyrus     unix  -       n       n       -       -       pipe
#  user=cyrus argv=/cyrus/bin/deliver -e -r ${sender} -m ${extension} ${user}
#
# ====================================================================
# Old example of delivery via Cyrus.
#
#old-cyrus unix  -       n       n       -       -       pipe
#  flags=R user=cyrus argv=/cyrus/bin/deliver -e -m ${extension} ${user}
#
# ====================================================================
#
# See the Postfix UUCP_README file for configuration details.
#
uucp      unix  -       n       n       -       -       pipe
  flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
#
# Other external delivery methods.
#
ifmail    unix  -       n       n       -       -       pipe
  flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp     unix  -       n       n       -       -       pipe
  flags=Fq. user=bsmtp argv=/usr/lib/bsmtp/bsmtp -t$nexthop -f$sender $recipient
scalemail-backend unix  -       n       n       -       2       pipe
  flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store ${nexthop} ${user} ${extension}
mailman   unix  -       n       n       -       -       pipe
  flags=FR user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py
  ${nexthop} ${user}
 
submission      inet    n       -       -       -       -       smtpd -o smtpd_sasl_auth_enable=yes

OhMyZSH / ZSH:

#Debian
apt-get install zsh curl
 
sh -c "$(curl -fsSL https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)"

MySQL:

Usually, I’d suggest using persona’s utility to figure out these values; I’ll post mine. https://tools.percona.com/

# Generated by Percona Configuration Wizard (https://tools.percona.com/) version REL5-20120208
# Configuration name sec02.takelan.com generated for ddemuro@gmail.com at 2015-04-11 05:31:01
 
[mysql]
 
# CLIENT #
port                           = 3306
socket                         = /var/run/mysqld/mysqld.sock
 
[mysqld]
 
# GENERAL #
user                           = mysql
default-storage-engine         = InnoDB
socket                         = /var/run/mysqld/mysqld.sock
pid-file                       = /var/run/mysqld/mysqld.pid
 
# MyISAM #
key-buffer-size                = 64M
myisam-recover                 = FORCE,BACKUP
 
# SAFETY #
max-allowed-packet             = 64M
max-connect-errors             = 1000000
skip-name-resolve
sql-mode                       = STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_AUTO_VALUE_ON_ZERO,NO_ENGINE_SUBSTITUTION,NO_ZERO_DATE,NO_ZERO_IN_DATE
sysdate-is-now                 = 1
innodb                         = FORCE
innodb-strict-mode             = 1
 
# DATA STORAGE #
datadir                        = /var/lib/mysql/
 
 
# BINARY LOGGING #
log-bin                        = /var/lib/mysql/mysql-bin
expire-logs-days               = 14
sync-binlog                    = 1
 
# CACHES AND LIMITS #
tmp-table-size                 = 512M
max-heap-table-size            = 512M
query-cache-type               = 1
query-cache-size               = 512M
query_cache_limit              = 16M
max-connections                = 500
thread-cache-size              = 80
open-files-limit               = 65535
table-definition-cache         = 4096
table-open-cache               = 10240
 
# INNODB #
innodb-flush-method            = O_DIRECT
innodb-log-files-in-group      = 2
#innodb-log-file-size           = 512M
innodb-flush-log-at-trx-commit = 1
innodb-file-per-table          = 1
innodb-buffer-pool-size        = 1G
 
# LOGGING #
log-error                      = /var/lib/mysql/mysql-error.log
log-queries-not-using-indexes  = 1
slow-query-log                 = 1
slow-query-log-file            = /var/lib/mysql/mysql-slow.log

PostGrey:

# postgrey whitelist for mail client hostnames
# --------------------------------------------
# put this file in /etc/postgrey or specify its path
# with --whitelist-clients=xxx
#
# postgrey version: 1.34, build date: 2011-05-04
 
# Debian-specific additions
# I *know* they run real mail queues, so greylisting only creates
# bigger load for them.
debconf.org
debian.org
spi-inc.org
 
# greylisting.org: Southwest Airlines (unique sender, no retry)
southwest.com
# greylisting.org: isp.belgacom.be (wierd retry pattern)
isp.belgacom.be
# greylisting.org: Ameritrade (no retry)
ameritradeinfo.com
# greylisting.org: Amazon.com (unique sender with letters)
amazon.com
# 2004-05-20: Linux kernel mailing-list (unique sender with letters)
vger.kernel.org
# 2004-06-02: karger.ch, no retry
karger.ch
# 2004-06-02: lilys.ch, (slow: 4 hours)
server-x001.hostpoint.ch
# 2004-06-09: roche.com (no retry)
gw.bas.roche.com
# 2004-06-09: newsletter (no retry)
mail.hhlaw.com
# 2004-06-09: no retry (reported by Ralph Hildebrandt)
prd051.appliedbiosystems.com
# 2004-06-17: swissre.com (no retry)
swissre.com
# 2004-06-17: dowjones.com newsletter (unique sender with letters)
returns.dowjones.com
# 2004-06-18: switch.ch (works but personnel is confused by the error)
domin.switch.ch
# 2004-06-23: accor-hotels.com (slow: 6 hours)
accor-hotels.com
# 2004-06-29: rr.com (no retry, reported by Duncan Hill)
/^ms-smtp.*\.rr\.com$/
# 2004-06-29: cox.net (no retry, reported by Duncan Hill)
/^lake.*mta.*\.cox\.net$/
# 2004-06-29: motorola.com (no retry)
mot.com
# 2004-07-01: nic.fr (address verification, reported by Arnaud Launay)
nic.fr
# 2004-07-01: verizon.net (address verification, reported by Bill Moran and Eric, adapted by Adam C. Mathews)
/^s[cv]\d+pub\.verizon\.net$/
# 2004-07-02: cs.columbia.edu (no retry)
cs.columbia.edu
# 2004-07-02: papersinvited.com (no retry)
66.216.126.174
# 2004-07-02: telekom.de (slow: 6 hours)
/^mail\d+\.telekom\.de$/
# 2004-07-04: tiscali.dk (slow: 12 hours, reported by Klaus Alexander Seistrup)
/^smtp\d+\.tiscali\.dk$/
# 2004-07-04: freshmeat.net (address verification)
freshmeat.net
# 2004-07-11: zd-swx.com (unique sender with letters, reported by Bill Landry)
zd-swx.com
# 2004-07-11: lockergnome.wc09.net (unique sender with letters, reported by Bill Landry)
lockergnome.wc09.net
# 2004-07-19: mxlogic.net (no retry, reported by Eric)
p01m168.mxlogic.net
p02m169.mxlogic.net
# 2004-09-08: intel.com (pool on different subnets) 
/^fmr\d+\.intel\.com$/
# 2004-09-17: cox-internet.com (no retry, reported by Rod Roark)
/^fe\d+\.cox-internet\.com$/
# 2004-10-11: logismata.ch (no retry)
logismata.ch
# 2004-11-25: brief.cw.reum.de (no retry, reported by Manuel Oetiker)
brief.cw.reum.de
# 2004-12-03: ingeno.ch (no retry)
qmail.ingeno.ch
# 2004-12-06: rein.ch (no retry)
mail1.thurweb.ch
# 2005-01-26: tu-ilmenau.de (no retry)
piggy.rz.tu-ilmenau.de
# 2005-04-06: polymed.ch (no retry)
mail.polymed.ch
# 2005-06-08: hu-berlin.de (slow: 6 hours, reported by Joachim Schoenberg)
rz.hu-berlin.de
# 2005-06-17: gmail.com (big pool, reported by Beat Mueller)
proxy.gmail.com
# 2005-06-23: cacert.org (address verification, reported by Martin Lohmeier)
cacert.org
# 2005-07-27: polytech.univ-mrs.fr (no retry, reported by Giovanni Mandorino)
polytech.univ-mrs.fr
# 2005-08-05: gnu.org (address verification, reported by Martin Lohmeier)
gnu.org
# 2005-08-17: ciphirelabs.com (needs fast responses, reported by Sven Mueller)
cs.ciphire.net
# 2005-11-11: lufthansa (no retry, reported by Peter Bieringer)
/^gateway\d+\.np4\.de$/
# 2005-11-23: arcor-online.net (slow: 12 hours, reported by Bernd Zeimetz)
/^mail-in-\d+\.arcor-online\.net$/
# 2005-12-29: netsolmail.com (no retry, reported by Gareth Greenaway)
netsolmail.com
# mail.likopris.si (no retry, reported by Vito Robar)
193.77.153.67
# jcsw.nato.int (several servers, no retry, reported by Vito Robar)
195.235.39
# tesla.vtszg.hr (no retry, reported by Vito Robar)
tesla.vtszg.hr
# mailgw*.iai.co.il (pool of several servers, reported by Vito Robar)
/^mailgw.*\.iai\.co\.il$/
# gw.stud-serv-mb.si (no retry, reported by Vito Robar)
gw.stud-serv-mb.si
# mail.commandtech.com (no retry, reported by Vito Robar)
216.238.112.99
# duropack.co.at (no retry, reported by Vito Robar)
193.81.20.195
# mail.esimit-tech.si (no retry, reported by Vito Robar)
193.77.126.208
# mail.resotel.be (ocasionally no retry, reported by Vito Robar)
80.200.249.216
# mail2.alliancefr.be (ocasionally no retry, reported by Vito Robar)
mail2.alliancefr.be
# webserver.turboinstitut.si (no retry, reported by Vito Robar)
webserver.turboinstitut.si
# mil.be (pool of different servers, reported by Vito Robar)
193.191.218.141
193.191.218.142
193.191.218.143
194.7.234.141
194.7.234.142
194.7.234.143
# mail*.usafisnews.org (no retry, reported by Vito Robar)
/^mail\d+\.usafisnews\.org$/
# odk.fdv.uni-lj.si (no retry, reported by Vito Robar)
/^odk.fdv.uni-lj.si$/
# rak-gentoo-1.nameserver.de (no retry, reported by Vito Robar)
rak-gentoo-1.nameserver.de
# dars.si (ocasionally no retry, reported by Vito Robar)
mx.dars.si
# cosis.si (no retry, reported by Vito Robar)
213.143.66.210
# mta?.siol.net (sometimes no or slow retry; they use intermail, reported by Vito Robar)
/^mta[12].siol.net$/
# pim-N-N.quickinspirationsmail.com (unique sender, reported by Vito Robar)
/^pim-\d+-\d+\.quickinspirationsmail\.com$/
# flymonarch (no retry, reported by Marko Djukic)
flymonarch.com
# wxs.nl (no retry, reported by Johannes Fehr)
/^p?smtp.*\.wxs\.nl$/
# ibm.com (big pool, reported by Casey Peel)
ibm.com
# messagelabs.com (big pool, reported by John Tobin)
/^mail\d+\.messagelabs\.com$/
# ptb.de (slow, reported by Joachim Schoenberg)
berlin.ptb.de
# registrarmail.net (unique sender names, reported by Simon Waters)
registrarmail.net
# google.com (big pool, reported by Matthias Dyer, Martin Toft)
google.com
# orange.fr (big pool, reported by Lo�c Le Loarer)
/^smtp\d+\.orange\.fr$/
# citigroup.com (slow retry, reported by Michael Monnerie)
/^smtp\d+.citigroup.com$/
# cruisingclub.ch (no retry)
mail.ccs-cruising.ch
# digg.com (no retry, Debian #406774)
diggstage01.digg.com
# liberal.ca (retries only during 270 seconds, Debian #406774)
smtp.liberal.ca
# pi.ws (pool + long retry, Debian #409851)
/^mail[12]\.pi\.ws$/
# rambler.ru (big pool, reported by Michael Monnerie)
rambler.ru
# free.fr (big pool, reported by Denis Sacchet)
/^smtp[0-9]+-g[0-9]+\.free\.fr$/
/^postfix[0-9]+-g[0-9]+\.free\.fr$/
# thehartford.com (pool + long retry, reported by Jacob Leifman)
/^netmail\d+\.thehartford\.com$/
# abb.com (only one retry, reported by Roman Plessl)
/^nse\d+\.abb\.com$/
# 2007-07-27: sourceforge.net (sender verification)
lists.sourceforge.net
# 2007-08-06: polytec.de (no retry, reported by Patrick McLean)
polytec.de
# 2007-09-06: qualiflow.com (no retry, reported by Alex Beckert)
/^mail\d+\.msg\.oleane\.net$/
# 2007-09-07: nrl.navy.mil (no retry, reported by Axel Beckert)
nrl.navy.mil
# 2007-10-18: aliplast.com (long retry, reported by Johannes Feigl)
mail.aliplast.com
# 2007-10-18: inode.at (long retry, reported by Johannes Feigl)
/^mx\d+\..*\.inode\.at$/
# 2008-02-01: bol.com (no retry, reported by Frank Breedijk)
/^.*?.server.arvato-systems.de$/
# 2008-06-05: registeredsite.com (no retry, reported by Fred Kilbourn)
/^(?:mail|fallback-mx)\d+.atl.registeredsite.com$/
# 2008-07-17: mahidol.ac.th (no retry, reported by Alex Beckert)
saturn.mahidol.ac.th
# 2008-07-18: ebay.com (big pool, reported by Peter Samuelson)
ebay.com
# 2008-07-22: yahoo.com (big pool, reported by Juan Alonso)
yahoo.com
# 2008-11-07: facebook (no retry, reported by Tim Freeman)
/^outmail\d+\.sctm\.tfbnw\.net$/
# 2009-02-10: server14.cyon.ch (long retry, reported by Alex Beckert)
server14.cyon.ch
# 2009-08-19: 126.com (big pool)
/^m\d+-\d+\.126\.com$/
# 2010-01-08: tifr.res.in (no retry, reported by Alex Beckert)
home.theory.tifr.res.in
# 2010-01-08: 1blu.de (long retry, reported by Alex Beckert)
ms4-1.1blu.de
# 2010-03-17: chello.at (big pool, reported by Jan-willem van Eys)
/^viefep\d+-int\.chello\.at$/
# 2010-05-31: nic.nu (long retry, reported by Ivan Sie)
mx.nic.nu
# 2010-06-10: Microsoft servers (long/no retry, reported by Roy McMorran)
bigfish.com
frontbridge.com
microsoft.com
# 2010-06-18: Google/Postini (big pool, reported by Warren Trakman)
postini.com
# 2011-02-04: evanzo-server.de (no retry, reported by Andre Hoepner)
/^mx.*\.evanzo-server\.de$/
# 2011-05-02: upcmail.net (big pool, reported by Michael Monnerie)
upcmail.net

# postgrey whitelist for mail recipients
# --------------------------------------
# put this file in /etc/postgrey or specify its path
# with --whitelist-recipients=xxx
 
postmaster@
abuse@

Spamassassin:

# This is the right place to customize your installation of SpamAssassin.
#
# See 'perldoc Mail::SpamAssassin::Conf' for details of what can be
# tweaked.
#
# Only a small subset of options are listed below
#
###########################################################################
 
#   Add *****SPAM***** to the Subject header of spam e-mails
#
# rewrite_header Subject *****SPAM*****
 
 
#   Save spam messages as a message/rfc822 MIME attachment instead of
#   modifying the original message (0: off, 2: use text/plain instead)
#
# report_safe 1
 
 
#   Set which networks or hosts are considered 'trusted' by your mail
#   server (i.e. not spammers)
#
# trusted_networks 212.17.35.
 
 
#   Set file-locking method (flock is not safe over NFS, but is faster)
#
# lock_method flock
 
 
#   Set the threshold at which a message is considered spam (default: 5.0)
#
# required_score 5.0
 
 
#   Use Bayesian classifier (default: 1)
#
# use_bayes 1
 
 
#   Bayesian classifier auto-learning (default: 1)
#
# bayes_auto_learn 1
 
 
#   Set headers which may provide inappropriate cues to the Bayesian
#   classifier
#
# bayes_ignore_header X-Bogosity
# bayes_ignore_header X-Spam-Flag
# bayes_ignore_header X-Spam-Status
 
 
#   Some shortcircuiting, if the plugin is enabled
# 
ifplugin Mail::SpamAssassin::Plugin::Shortcircuit
#
#   default: strongly-whitelisted mails are *really* whitelisted now, if the
#   shortcircuiting plugin is active, causing early exit to save CPU load.
#   Uncomment to turn this on
#
# shortcircuit USER_IN_WHITELIST       on
# shortcircuit USER_IN_DEF_WHITELIST   on
# shortcircuit USER_IN_ALL_SPAM_TO     on
# shortcircuit SUBJECT_IN_WHITELIST    on
 
#   the opposite; blacklisted mails can also save CPU
#
# shortcircuit USER_IN_BLACKLIST       on
# shortcircuit USER_IN_BLACKLIST_TO    on
# shortcircuit SUBJECT_IN_BLACKLIST    on
 
#   if you have taken the time to correctly specify your "trusted_networks",
#   this is another good way to save CPU
#
# shortcircuit ALL_TRUSTED             on
 
#   and a well-trained bayes DB can save running rules, too
#
# shortcircuit BAYES_99                spam
# shortcircuit BAYES_00                ham
 
endif # Mail::SpamAssassin::Plugin::Shortcircuit

Fail2Ban:

jail.conf

# Fail2Ban configuration file.
#
# This file was composed for Debian systems from the original one
#  provided now under /usr/share/doc/fail2ban/examples/jail.conf
#  for additional examples.
#
# To avoid merges during upgrades DO NOT MODIFY THIS FILE
# and rather provide your changes in /etc/fail2ban/jail.local
#
# Author: Yaroslav O. Halchenko <debian>
#
# $Revision$
#
 
# The DEFAULT allows a global definition of the options. They can be overridden
# in each jail afterwards.
 
[DEFAULT]
 
# "ignoreip" can be an IP address, a CIDR mask or a DNS host
ignoreip = 127.0.0.1/8
bantime  = 600
maxretry = 3
 
# "backend" specifies the backend used to get files modification. Available
# options are "gamin", "polling" and "auto".
# yoh: For some reason Debian shipped python-gamin didn't work as expected
#      This issue left ToDo, so polling is default backend for now
backend = auto
 
#
# Destination email address used solely for the interpolations in
# jail.{conf,local} configuration files.
destemail = root@localhost
 
#
# ACTIONS
#
 
# Default banning action (e.g. iptables, iptables-new,
# iptables-multiport, shorewall, etc) It is used to define
# action_* variables. Can be overridden globally or per
# section within jail.local file
banaction = iptables-multiport
 
# email action. Since 0.8.1 upstream fail2ban uses sendmail
# MTA for the mailing. Change mta configuration parameter to mail
# if you want to revert to conventional 'mail'.
mta = sendmail
 
# Default protocol
protocol = tcp
 
# Specify chain where jumps would need to be added in iptables-* actions
chain = INPUT
 
#
# Action shortcuts. To be used to define action parameter
 
# The simplest action to take: ban only
action_ = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
 
# ban & send an e-mail with whois report to the destemail.
action_mw = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
              %(mta)s-whois[name=%(__name__)s, dest="%(destemail)s", protocol="%(protocol)s", chain="%(chain)s"]
 
# ban & send an e-mail with whois report and relevant log lines
# to the destemail.
action_mwl = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
               %(mta)s-whois-lines[name=%(__name__)s, dest="%(destemail)s", logpath=%(logpath)s, chain="%(chain)s"]
 
# Choose default action.  To change, just override value of 'action' with the
# interpolation to the chosen action shortcut (e.g.  action_mw, action_mwl, etc) in jail.local
# globally (section [DEFAULT]) or per specific section
action = %(action_)s
 
#
# JAILS
#
 
# Next jails corresponds to the standard configuration in Fail2ban 0.6 which
# was shipped in Debian. Enable any defined here jail by including
#
# [SECTION_NAME]
# enabled = true
 
#
# in /etc/fail2ban/jail.local.
#
# Optionally you may override any other parameter (e.g. banaction,
# action, port, logpath, etc) in that section within jail.local
 
[ssh]
 
enabled  = true
port     = ssh
filter   = sshd
logpath  = /var/log/auth.log
maxretry = 6
 
[dropbear]
 
enabled  = false
port     = ssh
filter   = sshd
logpath  = /var/log/dropbear
maxretry = 6
 
# Generic filter for pam. Has to be used with action which bans all ports
# such as iptables-allports, shorewall
[pam-generic]
 
enabled  = false
# pam-generic filter can be customized to monitor specific subset of 'tty's
filter   = pam-generic
# port actually must be irrelevant but lets leave it all for some possible uses
port     = all
banaction = iptables-allports
port     = anyport
logpath  = /var/log/auth.log
maxretry = 6
 
[xinetd-fail]
 
enabled   = false
filter    = xinetd-fail
port      = all
banaction = iptables-multiport-log
logpath   = /var/log/daemon.log
maxretry  = 2
 
 
[ssh-ddos]
 
enabled  = false
port     = ssh
filter   = sshd-ddos
logpath  = /var/log/auth.log
maxretry = 6
 
#
# HTTP servers
#
 
[apache]
 
enabled  = false
port     = http,https
filter   = apache-auth
logpath  = /var/log/apache*/*error.log
maxretry = 6
 
# default action is now multiport, so apache-multiport jail was left
# for compatibility with previous (<0.7.6-2) releases
[apache-multiport]
 
enabled   = false
port      = http,https
filter    = apache-auth
logpath   = /var/log/apache*/*error.log
maxretry  = 6
 
[apache-noscript]
 
enabled  = false
port     = http,https
filter   = apache-noscript
logpath  = /var/log/apache*/*error.log
maxretry = 6
 
[apache-overflows]
 
enabled  = false
port     = http,https
filter   = apache-overflows
logpath  = /var/log/apache*/*error.log
maxretry = 2
 
#
# FTP servers
#
 
[vsftpd]
 
enabled  = false
port     = ftp,ftp-data,ftps,ftps-data
filter   = vsftpd
logpath  = /var/log/vsftpd.log
# or overwrite it in jails.local to be
# logpath = /var/log/auth.log
# if you want to rely on PAM failed login attempts
# vsftpd's failregex should match both of those formats
maxretry = 6
 
 
[proftpd]
 
enabled  = false
port     = ftp,ftp-data,ftps,ftps-data
filter   = proftpd
logpath  = /var/log/proftpd/proftpd.log
maxretry = 6
 
 
[pure-ftpd]
 
enabled  = false
port     = ftp,ftp-data,ftps,ftps-data
filter   = pure-ftpd
logpath  = /var/log/auth.log
maxretry = 6
 
 
[wuftpd]
 
enabled  = false
port     = ftp,ftp-data,ftps,ftps-data
filter   = wuftpd
logpath  = /var/log/auth.log
maxretry = 6
 
 
#
# Mail servers
#
 
[postfix]
 
enabled  = false
port     = smtp,ssmtp
filter   = postfix
logpath  = /var/log/mail.log
 
 
[couriersmtp]
 
enabled  = false
port     = smtp,ssmtp
filter   = couriersmtp
logpath  = /var/log/mail.log
 
 
#
# Mail servers authenticators: might be used for smtp,ftp,imap servers, so
# all relevant ports get banned
#
 
[courierauth]
 
enabled  = false
port     = smtp,ssmtp,imap2,imap3,imaps,pop3,pop3s
filter   = courierlogin
logpath  = /var/log/mail.log
 
 
[sasl]
 
enabled  = false
port     = smtp,ssmtp,imap2,imap3,imaps,pop3,pop3s
filter   = sasl
# You might consider monitoring /var/log/mail.warn instead if you are
# running postfix since it would provide the same log lines at the
# "warn" level but overall at the smaller filesize.
logpath  = /var/log/mail.log
 
[dovecot]
 
enabled = false
port    = smtp,ssmtp,imap2,imap3,imaps,pop3,pop3s
filter  = dovecot
logpath = /var/log/mail.log
 
# DNS Servers
 
 
# These jails block attacks against named (bind9). By default, logging is off
# with bind9 installation. You will need something like this:
#
# logging {
#     channel security_file {
#         file "/var/log/named/security.log" versions 3 size 30m;
#         severity dynamic;
#         print-time yes;
#     };
#     category security {
#         security_file;
#     };
# };
#
# in your named.conf to provide proper logging
 
# !!! WARNING !!!
#   Since UDP is connection-less protocol, spoofing of IP and imitation
#   of illegal actions is way too simple.  Thus enabling of this filter
#   might provide an easy way for implementing a DoS against a chosen
#   victim. See
#    https://nion.modprobe.de/blog/archives/690-fail2ban-+-dns-fail.html
#   Please DO NOT USE this jail unless you know what you are doing.
#[named-refused-udp]
#
#enabled  = false
#port     = domain,953
#protocol = udp
#filter   = named-refused
#logpath  = /var/log/named/security.log
 
[named-refused-tcp]
 
enabled  = false
port     = domain,953
protocol = tcp
filter   = named-refused
logpath  = /var/log/named/security.log
</debian>@onerussian.com>

fail2ban.conf

# Fail2Ban configuration file
#
# Author: Cyril Jaquier
#
# $Revision$
#
 
[Definition]
 
# Option:  loglevel
# Notes.:  Set the log level output.
#          1 = ERROR
#          2 = WARN
#          3 = INFO
#          4 = DEBUG
# Values:  NUM  Default:  3
#
loglevel = 3
 
# Option:  logtarget
# Notes.:  Set the log target. This could be a file, SYSLOG, STDERR or STDOUT.
#          Only one log target can be specified.
# Values:  STDOUT STDERR SYSLOG file  Default:  /var/log/fail2ban.log
#
logtarget = /var/log/fail2ban.log
 
# Option: socket
# Notes.: Set the socket file. This is used to communicate with the daemon. Do
#         not remove this file when Fail2ban runs. It will not be possible to
#         communicate with the server afterwards.
# Values: FILE  Default:  /var/run/fail2ban/fail2ban.sock
#
socket = /var/run/fail2ban/fail2ban.sock

Following this, we’ll install all we need to make munin service run and be optimized to what we need to monitor.

Lets install munin:

apt-get install munin munin-node munin-plugins-extra

Let’s enable some default plugins:

cd /etc/munin/plugins
ln -s /usr/share/munin/plugins/mysql_ mysql_
ln -s /usr/share/munin/plugins/mysql_bytes mysql_bytes
ln -s /usr/share/munin/plugins/mysql_innodb mysql_innodb
ln -s /usr/share/munin/plugins/mysql_isam_space_ mysql_isam_space_
ln -s /usr/share/munin/plugins/mysql_queries mysql_queries
ln -s /usr/share/munin/plugins/mysql_slowqueries mysql_slowqueries
ln -s /usr/share/munin/plugins/mysql_threads mysql_threads

Now let’s start editing the server configuration:

vi /etc/munin/munin.conf

More or less you should see something like this.

# Example configuration file for Munin, generated by 'make build'
 
# The next three variables specifies where the location of the RRD
# databases, the HTML output, logs and the lock/pid files.  They all
# must be writable by the user running munin-cron.  They are all
# defaulted to the values you see here.
#
dbdir   /var/lib/munin
htmldir /var/cache/munin/www
logdir /var/log/munin
rundir  /var/run/munin
 
# Where to look for the HTML templates
#
tmpldir /etc/munin/templates
 
# Where to look for the static www files
#
#staticdir /etc/munin/static
 
# temporary cgi files are here. note that it has to be writable by
# the cgi user (usually nobody or httpd).
#
# cgitmpdir /var/lib/munin/cgi-tmp
 
# (Exactly one) directory to include all files from.
includedir /etc/munin/munin-conf.d
[...]
# a simple host tree
[server1.example.com]
    address 127.0.0.1
    use_node_name yes
[...]

Now to finish the default’s lets restart munin and apache:

service apache2 restart
service munin-node restart

Some advanced stuff:

We need to check that we’re not missing any libraries for Munin to work correctly for this; let’s run:

munin-node-configure --suggest

Here a long list will appear saying what you’re missing, it’s common to see with MYSQL you’re missing cache pearl libs… so

apt-get install libcache-cache-perl

To work with plugins, you’ll be creating and removing system links, so…

cd /etc/munin/plugins
ln -s /usr/share/munin/plugins/apache_accesses

That would be an example on how to work with plugins.

I NEED BIND9!

Okay, don’t get crazy, lets work with bind9 and munin.

In: /etc/bind/named.conf.options we need to enable stat’s file, add the following line.

statistics-file "/var/cache/bind/named.stats";
logging {
        channel b_query {
                file "/var/log/bind9/query.log" versions 2 size 1m;
                print-time yes;
                severity info;
        };
        category queries { b_query; };
};

/var/log/bind9 > add that path, and chown to bind, and allow it to write the log there.

Next, lets tell munin to process that:

vi /etc/munin/plugin-conf.d/munin-node

[bind9]
user root
env.logfile   /var/log/bind9/query.log
 
[bind9_rndc]
user root
env.querystats /var/cache/bind/named.stats

Once that is done, lets make the symlinks.

ln -s /usr/share/munin/plugins/bind9 /etc/munin/plugins/bind9
ln -s /usr/share/munin/plugins/bind9_rndc /etc/munin/plugins/bind9_rndc

As usual restart munin-node!

DONE!.

REMEMBER TO RM [SYMLINKS] to plugins you don’t need, or Munin can turn into a huge memory hog… in my experience bind9 plugin… take’s a long time to process, leading to a sluggish system.

Okay, let’s go over the basics, we need to make sure plugins are installed correctly and its dependencies ofc.

Lets do some installing of Pearl and Spam Assassin.

perl -MCPAN -e shell
o conf commit prerequisites_policy ask
install Mail::SpamAssassin
quit

perl -MCPAN -e shell
o conf prerequisites_policy ask

force install Socket6 IO::Socket IO::Socket::INET6 LWP MD5 CPAN::DistnameInfo Mail::DKIM
force install Test::More MIME::Base64 Digest::MD5 Digest::HMAC_MD5 Net::IP
force install Net::Ping Net::DNS Time::HiRes Digest::SHA1 Getopt::Long Digest::Nilsimsa URI::Escape HTML::Parser HTTP::Date IO::Zlib Archive::Tar  Mail::SPF
force install Mail::SPF::Query Net::Ident IO::Socket::SSL Mail::DomainKeys Mail::DKIM LWP::UserAgent HTTP::Date Encode::Detect
install Storable DB_File Net::SMTP IP::Country::Fast BerkeleyDB
force install  Mail::SpamAssassin Mail::SpamAssassin::Plugin::Razor2

Once this has finished our dependencies should be met, let’s go over the config file for spam assassin. Find the INIT.PRE file:

# RelayCountry - add metadata for Bayes learning, marking the countries
# a message was relayed through
#
# Note: This requires the IP::Country::Fast Perl module
#
loadplugin Mail::SpamAssassin::Plugin::RelayCountry

# URIDNSBL - look up URLs found in the message against several DNS
# blocklists.
#
loadplugin Mail::SpamAssassin::Plugin::URIDNSBL

# Hashcash - perform hashcash verification.
#
loadplugin Mail::SpamAssassin::Plugin::Hashcash

# SPF - perform SPF verification.
#
loadplugin Mail::SpamAssassin::Plugin::SPF

Uncomment the plugins so they get loaded correctly, and update the rules by running:

sa-update

I’d also recommend adding that to your crontab to get periodically updated.

# spamassassin update
30 3 * * * /usr/bin/sa-update --nogpg -v &

-v will send mail to postmaster [selected upon installation]

user@user(link sends e-mail):~# service spamassassin restart ##Its always good to restart the service upon maintenance.

1) Make sure you have iptables, and a machine running linux. [Yeah… I know… Right?].

Remember how to use iptables? well, if you don’t let keep it simple, as I use Virtualmin in this scenario, I’ll show the simplest IPTABLES Config with DNAT and SNAT so you can understand where I’m going. I’d recommend saving your actual configuration; you can do so by going to your home directory and typing $ iptables-save > actual.rules

Okay, here is my config.

# Generated by iptables-save v1.4.8 on Mon Apr 29 19:31:49 2013
*mangle
:PREROUTING ACCEPT [1333:508988]
:INPUT ACCEPT [750:242327]
:FORWARD ACCEPT [583:266661]
:OUTPUT ACCEPT [722:155604]
:POSTROUTING ACCEPT [1305:422265]
COMMIT
# Completed on Mon Apr 29 19:31:49 2013
# Generated by iptables-save v1.4.8 on Mon Apr 29 19:31:49 2013
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [173729:23848230]
:OUTPUT ACCEPT [672239:56566207]
-A INPUT -p udp --dport 53 -m string --string "isc?org?" --algo kmp -j DROP
-A INPUT -p tcp -m tcp --dport 10000 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 20000 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 443 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 993 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 143 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 995 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 110 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 20 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 21 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 53 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 587 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 25 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT 
-A INPUT -p udp -m udp --dport 1194 -j ACCEPT 
-A INPUT -p tcp -m tcp --dport 1194 -j ACCEPT 
-A INPUT -j ACCEPT 
COMMIT
# Completed on Mon Apr 29 19:31:49 2013
# Generated by iptables-save v1.4.8 on Mon Apr 29 19:31:49 2013
*nat
:PREROUTING ACCEPT [36862:2468692]
:POSTROUTING ACCEPT [5010:305030]
:OUTPUT ACCEPT [714:46222]
-A PREROUTING -d 000.00.00.00/32 -j DNAT --to-destination 10.10.0.2 
-A POSTROUTING -s 10.10.0.0/24 -j SNAT --to-source 000.00.00.00 
COMMIT

# Completed on Mon Apr 29 19:31:49 2013

 What is those numbers blacked out 000.00.00.00 [This would be your actual ip you’re going to nat, in my case its a 1:1 nat.]

10.10.0.0 This would be your vpn's machine behind the NAT.

-A PREROUTING -d 000.00.00.00/32 -j DNAT –to-destination 10.10.0.2

-A POSTROUTING -s 10.10.0.0/24 -j SNAT --to-source 000.00.00.00

First line makes the forward that anything that gets to that ip must be sent to the vpn so your machine inside the vpn gets the traffic.

The second line does the opposite. In my case, the VPN is completely secured, so I again do 1:1 nat for all the tips inside the VPN, so all traffic generated inside the VPN can come out through the public IP.

2) Configure the Kernel to be able to forward IPv4 and IPv6 if you want… ofc.

$ echo 1 > /proc/sys/net/ipv4/ip_forward

That line will allow it just while the machine is running, once rebooted; you’re doomed, but if you want to try this, leave it like that, OR! If you’re a pro, let’s modify sysctl.

Pick the editor you hate mostly, in my case, Mr. vim /etc/sysctl.conf

And change the following lines:

# Uncomment the next line to enable packet forwarding for IPv4

#net.ipv4.ip_forward=1

# Uncomment the next line to enable packet forwarding for IPv6
#  Enabling this option disables Stateless Address Autoconfiguration
#  based on Router Advertisements for this host
#net.ipv6.conf.all.forwarding=1

To look just like:# Uncomment the next line to enable packet forwarding for IPv4

net.ipv4.ip_forward=1

# Uncomment the next line to enable packet forwarding for IPv6
#  Enabling this option disables Stateless Address Autoconfiguration
#  based on Router Advertisements for this host

net.ipv6.conf.all.forwarding=1

Then save the file, if you’re using vim coz you’re cool like me, just :wq in vim and you’re done!.

Have fun NATTING everywhere.

Check the TUN/TAP Adapter:

If you’re running it in a OpenVZ Container as we are:

Enter cat /dev/net/tun to test whether the TUN/TAP device is available:

• If you receive the message cat: /dev/net/tun: File descriptor in bad state your TUN/TAP device is ready for use
• If you receive the message cat: /dev/net/tun: No such device the TUN/TAP device was not successfully created: 

We need to start the ssh to the server.

ssh user@domain.com(link sends e-mail)

Install all the necessary files:

sudo apt-get install openvpn udev

Copy the example files:

sudo cp -r /usr/share/doc/openvpn/examples/easy-rsa /etc/openvpn

Move to the folder in openvpn:

cd /etc/openvpn/easy-rsa/2.0/

Generate RSA Keys:

sudo ./vars

sudo ./clean-all

sudo ./build-ca

We now we now build the server key

sudo . /etc/openvpn/easy-rsa/2.0/build-key-server server

We Generate Deffie Hoffmann

sudo . /etc/openvpn/easy-rsa/2.0/build-dh

We now create one key per certificate we wish to create:

sudo . /etc/openvpn/easy-rsa/2.0/build-key client

sudo cp /etc/openvpn/easy-rsa/2.0/keys/ca.crt /etc/openvpn

sudo cp /etc/openvpn/easy-rsa/2.0/keys/ca.key /etc/openvpn

sudo cp /etc/openvpn/easy-rsa/2.0/keys/dh1024.pem /etc/openvpn

sudo cp /etc/openvpn/easy-rsa/2.0/keys/server.crt /etc/openvpn

sudo cp /etc/openvpn/easy-rsa/2.0/keys/server.key /etc/openvpn

If you already have certificates to add new you need to:

source ./vars

build-key [name]

ALL DONE!.

In the future to remove or revoke a certificate:

sudo . /etc/openvpn/easy-rsa/2.0/vars

sudo . /etc/openvpn/easy-rsa/2.0/revoke-full client1

Finally navigate to /etc/openvpn and create server.conf with the necessary parameters.

Config Example ahead:

#################################################
# Sample OpenVPN 2.0 config file for            #
# multi-client server.                          #
#                                               #
# This file is for the server side              #
# of a many-clients <-> one-server              #
# OpenVPN configuration.                        #
#                                               #
# OpenVPN also supports                         #
# single-machine <-> single-machine             #
# configurations (See the Examples page         #
# on the web site for more info).               #
#                                               #
# This config should work on Windows            #
# or Linux/BSD systems.  Remember on            #
# Windows to quote pathnames and use            #
# double backslashes, e.g.:                     #
# "C:\\Program Files\\OpenVPN\\config\\foo.key" #
#                                               #
# Comments are preceded with '#' or ';'         #
#################################################

# Which local IP address should OpenVPN
# listen on? (optional)
#local [ip]

# Which TCP/UDP port should OpenVPN listen on?
# If you want to run multiple OpenVPN instances
# on the same machine, use a different port
# number for each one.  You will need to
# open up this port on your firewall.
port [port]

# TCP or UDP server?
;proto tcp
proto udp

# "dev tun" will create a routed IP tunnel,
# "dev tap" will create an ethernet tunnel.
# Use "dev tap0" if you are ethernet bridging
# and have precreated a tap0 virtual interface
# and bridged it with your ethernet interface.
# If you want to control access policies
# over the VPN, you must create firewall
# rules for the the TUN/TAP interface.
# On non-Windows systems, you can give
# an explicit unit number, such as tun0.
# On Windows, use "dev-node" for this.
# On most systems, the VPN will not function
# unless you partially or fully disable
# the firewall for the TUN/TAP interface.
;dev tap
dev tun

# Windows needs the TAP-Win32 adapter name
# from the Network Connections panel if you
# have more than one.  On XP SP2 or higher,
# you may need to selectively disable the
# Windows firewall for the TAP adapter.
# Non-Windows systems usually don't need this.
;dev-node MyTap

# SSL/TLS root certificate (ca), certificate
# (cert), and private key (key).  Each client
# and the server must have their own cert and
# key file.  The server and all clients will
# use the same ca file.
#
# See the "easy-rsa" directory for a series
# of scripts for generating RSA certificates
# and private keys.  Remember to use
# a unique Common Name for the server
# and each of the client certificates.
#
# Any X509 key management system can be used.
# OpenVPN can also use a PKCS #12 formatted key file
# (see "pkcs12" directive in man page).
ca ca.crt
cert server.crt
key server.key  # This file should be kept secret

# Diffie hellman parameters.
# Generate your own with:
#   openssl dhparam -out dh1024.pem 1024
# Substitute 2048 for 1024 if you are using
# 2048 bit keys. 
dh dh1024.pem

# Configure server mode and supply a VPN subnet
# for OpenVPN to draw client addresses from.
# The server will take 10.8.0.1 for itself,
# the rest will be made available to clients.
# Each client will be able to reach the server
# on 10.8.0.1. Comment this line out if you are
# ethernet bridging. See the man page for more info.
server 10.0.10.0 255.255.255.0

# Maintain a record of client <-> virtual IP address
# associations in this file.  If OpenVPN goes down or
# is restarted, reconnecting clients can be assigned
# the same virtual IP address from the pool that was
# previously assigned.
ifconfig-pool-persist ipp.txt

# Configure server mode for ethernet bridging.
# You must first use your OS's bridging capability
# to bridge the TAP interface with the ethernet
# NIC interface.  Then you must manually set the
# IP/netmask on the bridge interface, here we
# assume 10.8.0.4/255.255.255.0.  Finally we
# must set aside an IP range in this subnet
# (start=10.8.0.50 end=10.8.0.100) to allocate
# to connecting clients.  Leave this line commented
# out unless you are ethernet bridging.
;server-bridge 10.8.0.4 255.255.255.0 10.8.0.50 10.8.0.100

# Configure server mode for ethernet bridging
# using a DHCP-proxy, where clients talk
# to the OpenVPN server-side DHCP server
# to receive their IP address allocation
# and DNS server addresses.  You must first use
# your OS's bridging capability to bridge the TAP
# interface with the ethernet NIC interface.
# Note: this mode only works on clients (such as
# Windows), where the client-side TAP adapter is
# bound to a DHCP client.
;server-bridge

# Push routes to the client to allow it
# to reach other private subnets behind
# the server.  Remember that these
# private subnets will also need
# to know to route the OpenVPN client
# address pool (10.8.0.0/255.255.255.0)
# back to the OpenVPN server.
;push "route 192.168.10.0 255.255.255.0"
;push "route 192.168.20.0 255.255.255.0"

# To assign specific IP addresses to specific
# clients or if a connecting client has a private
# subnet behind it that should also have VPN access,
# use the subdirectory "ccd" for client-specific
# configuration files (see man page for more info).

# EXAMPLE: Suppose the client
# having the certificate common name "Thelonious"
# also has a small subnet behind his connecting
# machine, such as 192.168.40.128/255.255.255.248.
# First, uncomment out these lines:
;client-config-dir ccd
;route 192.168.40.128 255.255.255.248
# Then create a file ccd/Thelonious with this line:
#   iroute 192.168.40.128 255.255.255.248
# This will allow Thelonious' private subnet to
# access the VPN.  This example will only work
# if you are routing, not bridging, i.e. you are
# using "dev tun" and "server" directives.

# EXAMPLE: Suppose you want to give
# Thelonious a fixed VPN IP address of 10.9.0.1.
# First uncomment out these lines:
client-config-dir ccd
;route 10.9.0.0 255.255.255.252
# Then add this line to ccd/Thelonious:
#   ifconfig-push 10.9.0.1 10.9.0.2

# Suppose that you want to enable different
# firewall access policies for different groups
# of clients.  There are two methods:
# (1) Run multiple OpenVPN daemons, one for each
#     group, and firewall the TUN/TAP interface
#     for each group/daemon appropriately.
# (2) (Advanced) Create a script to dynamically
#     modify the firewall in response to access
#     from different clients.  See man
#     page for more info on learn-address script.
;learn-address ./script

# If enabled, this directive will configure
# all clients to redirect their default
# network gateway through the VPN, causing
# all IP traffic such as web browsing and
# and DNS lookups to go through the VPN
# (The OpenVPN server machine may need to NAT
# or bridge the TUN/TAP interface to the internet
# in order for this to work properly).
;push "redirect-gateway def1 bypass-dhcp"

# Certain Windows-specific network settings
# can be pushed to clients, such as DNS
# or WINS server addresses.  CAVEAT:
# https://openvpn.net/faq.html#dhcpcaveats
# The addresses below refer to the public
# DNS servers provided by opendns.com.
;push "dhcp-option DNS 208.67.222.222"
;push "dhcp-option DNS 208.67.220.220"

# Uncomment this directive to allow different
# clients to be able to "see" each other.
# By default, clients will only see the server.
# To force clients to only see the server, you
# will also need to appropriately firewall the
# server's TUN/TAP interface.
client-to-client

# Uncomment this directive if multiple clients
# might connect with the same certificate/key
# files or common names.  This is recommended
# only for testing purposes.  For production use,
# each client should have its own certificate/key
# pair.
#
# IF YOU HAVE NOT GENERATED INDIVIDUAL
# CERTIFICATE/KEY PAIRS FOR EACH CLIENT,
# EACH HAVING ITS OWN UNIQUE "COMMON NAME",
# UNCOMMENT THIS LINE OUT.
duplicate-cn

# The keepalive directive causes ping-like
# messages to be sent back and forth over
# the link so that each side knows when
# the other side has gone down.
# Ping every 10 seconds, assume that remote
# peer is down if no ping received during
# a 120 second time period.
keepalive 10 50

# For extra security beyond that provided
# by SSL/TLS, create an "HMAC firewall"
# to help block DoS attacks and UDP port flooding.
#
# Generate with:
#   openvpn --genkey --secret ta.key
#
# The server and each client must have
# a copy of this key.
# The second parameter should be '0'
# on the server and '1' on the clients.
tls-auth ta.key 0 # This file is secret

# Select a cryptographic cipher.
# This config item must be copied to
# the client config file as well.
cipher BF-CBC        # Blowfish (default)
;cipher AES-128-CBC   # AES
;cipher DES-EDE3-CBC  # Triple-DES

# Enable compression on the VPN link.
# If you enable it here, you must also
# enable it in the client config file.
comp-lzo

# The maximum number of concurrently connected
# clients we want to allow.
max-clients 15

# It's a good idea to reduce the OpenVPN
# daemon's privileges after initialization.
#
# You can uncomment this out on
# non-Windows systems.
;user nobody
;group nogroup

# The persist options will try to avoid
# accessing certain resources on restart
# that may no longer be accessible because
# of the privilege downgrade.
persist-key
persist-tun

# Output a short status file showing
# current connections, truncated
# and rewritten every minute.
status openvpn-status.log

# By default, log messages will go to the syslog (or
# on Windows, if running as a service, they will go to
# the "\Program Files\OpenVPN\log" directory).
# Use log or log-append to override this default.
# "log" will truncate the log file on OpenVPN startup,
# while "log-append" will append to it.  Use one
# or the other (but not both).
;log         openvpn.log
;log-append  openvpn.log

# Set the appropriate level of log
# file verbosity.
#
# 0 is silent, except for fatal errors
# 4 is reasonable for general usage
# 5 and 6 can help to debug connection problems
# 9 is extremely verbose
verb 3

# Silence repeating messages.  At most 20
# sequential messages of the same message
# category will be output to the log.
mute 20

We need two files on the backup mail server: a list of domains to relay and a list of valid email accounts. With a little tweaking, we can copy a couple of Virtualmin configuration files over from the primary, and the backup will automatically know what the valid accounts are.

Note: if you’re using Virtualmin, make sure your alias domains are copying the accounts from the domain they are aliasing rather than running a catch-all domain (which is the default setting); otherwise, it rather defeats the purpose of specifying the valid accounts. To set this up on future-created domains, go to System Settings, Server Templates, select your template(s), go to Mail for a domain, and change “Mail alias mode for alias domains” to “Copy aliases from target” and Save. If you have existing catch-all alias domains, if you select that domain and go to Server Configuration, Email Settings, you can change the Mail aliases mode.

So, back to those two files. They need to be files that Postfix can map into a hash file for itself to use. The standard way of doing this is to have the domain (or email address) and then space and then the wordOK, so each line would be:
user@domain.com OK

However, the second part can be anything for the hash to work, it doesn’t have to be, and Virtualmin creates a virtual mapping file that maps email addresses to accounts that we can use as an excellent relay recipient list. The data is at/etc/postfix/virtualso the first step is to copy that file to the backup as/etc/postfix/relay_recipients. (This will all need to be done as therootuser.)

[primary] scp /etc/postfix/virtual user@backupmx.com:~
[backup] cp /home/user/virtual /etc/postfix/relay_recipients

Then we need to tell Postfix to use those email addresses, so as root:

[backup] postmap /etc/postfix/relay_recipients

If that fails, you may need to adjust the permissions of/etc/postfixso that it can create the .db file (and then rerun the command):

[backup] chmod 777 /etc/postfix
[backup] postmap /etc/postfix/relay_recipients

Then update the Postfix configuration and reload it:

[backup] postconf -e "relay_recipient_maps = hash:/etc/postfix/relay_recipients"
[backup] postfix reload

Next, we need a list of valid domains to relay. Virtualmin does create a map of domains for itself with the formatdomain.com=1234567890, so all we need to do it replace the equals sign with space, and we have a valid map file.

[primary] scp /etc/webmin/virtual-server/map.dom user@backupmx.com:~
[backup] sed -i 's/=/ /g' /home/user/map.dom
[backup] cp /home/user/map.dom /etc/postfix/relay_domains

Then similar to above, update the config and reload:

[backup] postmap /etc/postfix/relay_domains
[backup] postconf -e "relay_domains = hash:/etc/postfix/relay_domains"
[backup] postfix reload

That’s it! If there were no problems, they are now in sync.

You don’t want to have to do this manually each time, so we need to set up an ssh key-pair so that you don’t have to enter your password and then create scripts that we will run automatically every few minutes to retain the sync.

Creating a passwordless key-pair is pretty simple. Type in:

[primary] ssh-keygen -t rsa

Use the default info and no password. Then copy to the backup:

[primary] ssh-copy-id -i ~/.ssh/id_rsa.pub user@backup.com

Enter the remote password. All done.

Now we need to create the scripts:

[primary] vi /home/user/backupmx.sh

What we’ll do is check if Virtualmin’s files are newer than the ones we last copied to the backup and, if so, then copy over the original data (having updated the domain map). So paste in:

#!/bin/sh
# postfix/vmin backup mx file 1/2 (primary)
# copy virtual (valid email addresses)
 if test /etc/postfix/virtual -nt /home/user/virtual
  then
  cp /etc/postfix/virtual /home/user/virtual
  scp /home/user/virtual user@backupmx.com:~
 fi
# copy map.dom (list of domains)
 if test /etc/webmin/virtual-server/map.dom -nt /home/user/map.dom
  then
  cp /etc/webmin/virtual-server/map.dom /home/user/map.dom
  sed -i 's/=/ /g' /home/user/map.dom
  scp /home/user/map.dom user@backupmx.com:~
 fi

And a similar script on the backup – check if the files are newer and if so, copy them and update the config:

[backup] vi /home/user/backupmx.sh

And paste in:

#!/bin/sh
# postfix/vmin backup mx file 2/2 (backup)
# copy virtual (valid email addresses)
 if test /home/user/virtual -nt /etc/postfix/relay_recipients
  then
  cp /home/user/virtual /etc/postfix/relay_recipients
  /usr/sbin/postmap /etc/postfix/relay_recipients
  /usr/sbin/postfix reload
 fi
# copy map.dom (list of domains)
 if test /home/user/map.dom -nt /etc/postfix/relay_domains
  then
  cp /home/user/map.dom /etc/postfix/relay_domains
  /usr/sbin/postmap /etc/postfix/relay_domains
  /usr/sbin/postfix reload
 fi

Then add those files to the cron on both systems

[primary] crontab -e

And add the line (to run every 5 minutes):

*/5 * * * * /home/user/backupmx.sh

Do the same on the backup computer.

Voila. Automated secondary mail server.