Postfix fails to start with IPv6 disabled

This document (000020356) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server 12

Situation

The postfix mail service fails to start on boot. When attempting to manually start the postfix.service, the following errors are observed:

# systemctl start postfix.service
Job for postfix.service failed because the control process exited with error code.
See "systemctl status postfix.service" and "journalctl -xe" for details.

# postconf -n
postconf: fatal: parameter inet_interfaces: no local interface found for ::1

The service status shows:

# systemctl status postfix.service
● postfix.service - Postfix Mail Transport Agent
Loaded: loaded (/usr/lib/systemd/system/postfix.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Fri 2021-07-30 15:25:31 MDT; 35s ago
Process: 26340 ExecStartPre=/bin/echo Starting mail service (Postfix) (code=exited, status=0/SUCCESS)
Process: 26341 ExecStartPre=/usr/lib/postfix/systemd/config_postfix (code=exited, status=0/SUCCESS)
Process: 26342 ExecStartPre=/usr/lib/postfix/systemd/update_chroot (code=exited, status=0/SUCCESS)
Process: 26343 ExecStartPre=/usr/lib/postfix/systemd/update_postmaps (code=exited, status=0/SUCCESS)
Process: 26366 ExecStart=/usr/sbin/postfix start (code=exited, status=1/FAILURE)
Process: 26367 ExecStopPost=/usr/lib/postfix/systemd/cond_slp deregister (code=exited, status=0/SUCCESS)

Jul 30 15:25:27 sles15sp3 update_postmaps[26363]: postmap: fatal: parameter inet_interfaces: no local interface found for ::1
Jul 30 15:25:27 sles15sp3 postfix/postmap[26363]: fatal: parameter inet_interfaces: no local interface found for ::1
Jul 30 15:25:28 sles15sp3 update_postmaps[26364]: chmod: cannot access '/etc/postfix/relay.': No such file or directory
Jul 30 15:25:28 sles15sp3 update_postmaps[26365]: postalias: fatal: parameter inet_interfaces: no local interface found for ::1
Jul 30 15:25:28 sles15sp3 postfix/postalias[26365]: fatal: parameter inet_interfaces: no local interface found for ::1
Jul 30 15:25:29 sles15sp3 postfix[26366]: fatal: parameter inet_interfaces: no local interface found for ::1
Jul 30 15:25:30 sles15sp3 systemd[1]: postfix.service: Control process exited, code=exited, status=1/FAILURE
Jul 30 15:25:30 sles15sp3 cond_slp[26369]: /usr/sbin/postconf: fatal: parameter inet_interfaces: no local interface found for :>
Jul 30 15:25:31 sles15sp3 systemd[1]: postfix.service: Failed with result 'exit-code'.
Jul 30 15:25:31 sles15sp3 systemd[1]: Failed to start Postfix Mail Transport Agent.

The /etc/hosts file contains the line:

::1 localhost ipv6-localhost ipv6-loopback

However, IPv6 has been disabled as the wicked status shows no ipv6 loop back address.

# /usr/sbin/wicked ifstatus --verbose all
lo up
link: #1, state up
type: loopback
control: persistent
config: compat:suse:/etc/sysconfig/network/ifcfg-lo,
uuid: a61d5ae3-71ce-57e7-bfe6-1de2346227bf
leases: ipv4 static granted
addr: ipv4 127.0.0.1/8 scope host label lo [static]

Resolution

There are two options available to resolve the issue.

Option 1 - Enable IPv6

1. Run yast lan > Global Options > check Enable IPv6 > select OK
2. Reboot the server to finish enabling IPv6

NOTE: A server reboot is required.

Option 2 - Leave IPv6 disabled and remove the IPv6 line in /etc/hosts

1. Edit /etc/hosts
2. Delete the line:

::1 localhost ipv6-localhost ipv6-loopback

3. Save and quit
4. Run systemctl restart postfix.service

Cause

IPv6 configuration found in /etc/hosts when IPv6 was not enabled.

Disclaimer

This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.