Configuring for IP V6
Zimbra Server with IPv6
First install Zimbra using ipv4 only mode. You can check the current Zimbra IP mode by running the following command as the user`zimbra`:
zmprov gs `zmhostname` zimbraIPMode
Then verify if all entries required all present in /etc/hosts file. Here is an example:
127.0.0.1 localhost.localdomain localhost :: 1 localhost.localdomain localhost 10.0.0.181 mail3.zimbra.tech mail3 2603:c020:400d:567e:aa22:ab12:1234:2a34 mail3.zimbra.tech mail3
Please make sure the localhost entries are as above for both ip4 and ip6 on your system before continuing!
In this example the server name is mail3.zimbra.tech, replace above example with your own domain name. For ip4 the server address for (mail3) your server can be the external IP or the LAN IP if you are in a NAT environment. For ip6 the server address for (mail3) your server should be the external IP in 99% of the cases.
Enable Zimbra in dual stack mode
Run the following command as the user zimbra:
sudo su - zimbra zmprov ms `zmhostname` zimbraIPMode both /opt/zimbra/libexec/zmiptool
zmiptool can take a bit of time. If zmiptool does not return any error, restart the Zimbra using:
zmcontrol restart
In case zmiptool does return errors, fix them before restarting Zimbra.
Update zimbraMailTrustedIP
After adding ip6 make sure to update the zimbraMailTrustedIP setting see: https://wiki.zimbra.com/wiki/Secopstips#Log_the_correct_origination_IP
Enclose zimbraMailTrustedIP in square brackets (eg. [1a01:2300:1f1:3:0:0:ffa:123]) the ipv6 address getting enclosed in zimbraMailTrustedIP should be in long format divided into 8 parts separated by colon. (eg. 1a01:2300:1f1:3::ffa:123 should be written like [1a01:2300:1f1:3:0:0:ffa:123]). The IPv6 addresses can be copy/pasted directly from mailbox.log.
Gotchas
If you use DNSMASQ or any other DNS cache on the Zimbra system, you need to restart DNSMASQ after changing /etc/hosts file using:
systemctl restart dnsmasq
