Werk #19206: win_netstat: Improve handling of Windows-specific TCP connection states

Component

Checks & agents

Title

win_netstat: Improve handling of Windows-specific TCP connection states

Date

May 13, 2026

Level

Trivial Change

Class

Bug Fix

Compatibility

Compatible - no manual interaction needed

Checkmk versions & editions

2.6.0b1 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT
2.5.0p3	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

Previously, the win_netstat check plugin could crash with a KeyError when encountering certain TCP connection state names reported by Windows. Some valid Windows-specific state representations were not recognized, causing the check to fail entirely for the affected host.

This is a follow-up to Werk #19201.

Starting with this release, additional Windows-specific TCP state names are correctly mapped to their standard equivalents. Furthermore, any connection state that is not recognized is now mapped to a default value instead of raising an error, so the check no longer crashes on unexpected state names.

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