Internet Protocol version 6 (IPv6) was designed by the Internet Engineering Task Force (the IETF) to expand the amount of IP addresses available. IPv6 addresses are 128-bit addresses, expressed in hexadecimal notation (for example, 2001:DB8:8::260:97ff:fe40:efab). There are 2128 IPv6 addresses, or roughly 340 trillion, trillion, trillion. This huge amount of addresses is expected to accommodate the predicted expansion of the Internet and Internet-related services over the coming years. IPv6 was introduced in 1999 and has been in use since then. This means that the core standards are stable and have been well tested in research and operational contexts.
The later versions of Directadmin have improved in their IPv6 support. In this post we’re going to setup IPv6 on a Directadmin server.
Configuration
1. Start with updating your Directadmin server. Login into your Directadmin server at port 2222 and update the Directadmin version.
Now grab some coffee, eat a donut and give Directadmin a few minutes to update itself.
2. Once Directadmin is updated, we can tell it to use IPv6. To do this, login with SSH and open the Directadmin configuration.
vi /usr/local/directadmin/conf/directadmin.conf
Check if there is a rule ipv6, add it if it doesn’t exist and make it look like:
ipv6=1
And restart Directadmin:
/etc/init.d/directadmin restart
3. With this option Directadmin can handle IPv6 IPs so let’s add one to the IP Manager. With IPv6, you have to use the prefix notation (like /64).
4. You can assign IPs to users just as you do normally. Thanks to the multi-IP system, you can assign an IPv4 and an IPv6 address to an user.
Go the the admin level in Directadmin and click Show all users.
Select the user you want to add an IPv6 address to.
Click on Modify user %username%.
Add the addition IPv6 IP.
The end result will look like this.
5. Check if your Exim installation has IPv6 compiled in. Login with SSH and type:
exim -bV | grep -i ipv6
If you get output, your Exim installation has IPv6 compiled in. If this isn’t the case, you have to recompile Exim from source. Please use the manual if this is the case.
6. For Dovecot, you have to make a small adjustment. Check the version of Dovecot:
dovecot --version
If your dovecot version is 2.0.0+, change your dovecot.conf.
vi /etc/dovecot.conf
Change this lines:
#IPv4 listen = * #IPv4 and IPv6: #listen = *, ::
To:
#IPv4 #listen = * #IPv4 and IPv6: listen = *, ::
If your dovecot version is 1.2.x, open up your dovecot.conf.
vi /etc/dovecot.conf
And add this line to the top of the file:
listen = "*, [::]"
The last step is to restart dovecot:
service dovecot restart
7. You are done! Your Directadmin installation is ready for IPv6 and you can add some AAAA records in your DNS to use IPv6.