DOvecot requires both IPv4 and IPV6 to start
Hello,
I hope this is the right place to start. Ubuntu server the default listener configuration in dovecot.conf uses both IP4 and IP6 on systems that have IP6 disabled dovecot will not start.
Is it possible to set the default to:
listen = * to only bind to IP4 for installation and initial start. Rather than listen = *, :: which tries to bind to a non existent IP6 stack. Or simply fallback to ip4 if ip6 is not available.
Thank you
Am 04.09.23 um 13:24 schrieb TWHG Technical via dovecot:
Hello,
I hope this is the right place to start. Ubuntu server the default listener configuration in dovecot.conf uses both IP4 and IP6
I think that is a good default value.
on systems that have IP6 disabled dovecot will not start.
That's not so good.
Is it possible to set the default to:
listen = * to only bind to IP4 for installation and initial start. Rather than listen = *, :: which tries to bind to a non existent IP6 stack.
I don't like that idea. It could break other installations. The default should stay at dual stack.
Or simply fallback to ip4 if ip6 is not available.
Maybe that is an good idea. But you are responsible for the missing network connectivity / IPv6, so please adjust your settings.
Regards, Thomas
--
There’s no place like ::1
Thomas Schäfer (Systemverwaltung) Ludwig-Maximilians-Universität Centrum für Informations- und Sprachverarbeitung Oettingenstraße 67 Raum C109 80538 München ☎ +49/89/2180-9706 ℻ +49/89/2180-9701
On 04.09.23 13:24, TWHG Technical wrote:
on systems that have IP6 disabled dovecot will not start.
Define "disabled", please. I don't have many Ubuntu systems around, but on the RHEL/CentOS/Fedora ones, even if they have IPv6 set to "Ignore", the interfaces get link-local IPv6 addresses assigned - at which point IPv6 LISTENs will work, too.
Of course, if you "disabled" IPv6 by compiling a kernel without the code relevant to it (is it still possible to do that?), various things might break *hard* ...
Kind regards,
Jochen Bern Systemingenieur
Binect GmbH
On 9/4/23 8:11 AM, Jochen Bern wrote:
Both NetworkManager and netplan(5) allow one to disable IPv6 without a kernel recompile. All my servers have IPv6 completely turned off.
My instance of dovecot works because I specified IPv4 only in the configuration file, specifically /etc/dovecot/conf.d/10-master.conf -- and here is what I wrote to the original poster:
- TWHG Technical via dovecot:
I hope this is the right place to start.
Not really. What you are asking for (changing the default configuration provided by Ubuntu) is something better asked of the Ubuntu package maintainers, should they even agree with your assessment. They might tell you that adapting the packaged configuration manually is a basic requirement, and also that running a server without IPv6 in 2023 is likely to cause some issues.
-Ralph
participants (6)
-
Jochen Bern
-
Ralph Seichter
-
Stephen Satchell
-
Thomas Schäfer
-
TWHG Technical
-
William Edwards