====== Disable ipv6 support ======

===== Apache =====

By default, Apache will listen on all IPs, both IPv6 and IPv4. This is controlled by the Listen directive:
<code>
Listen 80
</code>
To turn off IPv6 in Apache, just change the Listen directive in ''/etc/apache2/ports.conf'' to
<code>
Listen 0.0.0.0:80
</code>
Repeat this for port 443 for HTTPS connections.

Then restart apache
<code>
/etc/init.d/apache2 restart
</code>

===== SSHD =====

By default, SSHD will listen on all IPs. This is configured in ''/etc/ssh/sshd_config'' as ListenAddress option.
To force SSHD to only listen to IPv4 explicitly set this:
<code>
ListenAddress 0.0.0.0
</code>
Then restart SSHD
<code>
/etc/init.d/ssh restart
</code>

===== postfix =====

<code>
vi /etc/postfix/main.cf 
</code>

Add inet_protocols line after inet_interfaces:
<code>
inet_protocols = ipv4
</code>
and restart postfix
<code>
/etc/init.d/postfix restart
</code>

===== Dovecot =====

<code>
vi /etc/dovecot/dovecot.conf
</code>

and add/change listen after the protocols = imap etc line, so it reads
<code>
listen = *
</code>
and restart dovecot
<code>
/etc/init.d/dovecot restart
</code>

===== EXIM =====

<code>
vi /etc/exim4/update-exim4.conf.conf
</code>

and change dc_local_interfaces so it reads
<code>
dc_local_interfaces='127.0.0.1'
</code>
and restart exim
<code>
/etc/init.d/exim4 restart
</code>

===== x11vnc =====
x11vnc has a -no6 option. This was broken in libvncserver1 package before 0.9.11.
<code>
x11vnc -no6
</code>

===== System wide =====

<code>
echo "# Disable IPv6" >> /etc/sysctl.conf
echo "net.ipv6.conf.all.disable_ipv6 = 1" >> /etc/sysctl.conf
echo "#" >> /etc/sysctl.conf
sysctl -p
</code>

reboot system at some point


===== Confirm open connections =====

<code>
lsof -i
</code>