Werk #20088: SmartPing: fix failure when IPv6 is disabled at kernel level

Component

The Checkmk Micro Core

Title

SmartPing: fix failure when IPv6 is disabled at kernel level

Date

Jun 8, 2026

Level

Trivial Change

Class

Bug Fix

Compatibility

Compatible - no manual interaction needed

Checkmk versions & editions

3.0.0b1 Not yet released	Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT
2.5.0p6	Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

When IPv6 was disabled at the kernel level via the boot parameter ipv6.disable=1, SmartPing failed to start and was unable to monitor any hosts, including those reachable via IPv4.

This issue did not occur when IPv6 was disabled via sysctl (net.ipv6.conf.all.disable_ipv6=1).

SmartPing now detects that IPv6 is unavailable at startup, logs a warning, and continues operating in IPv4-only mode.

To the list of all Werks