the phone-home register

NetworkManager

What NetworkManager sends out of your computer by default, when, to whom, and the switch that stops it, version by version, with how we know.

The answer

Per NetworkManager's manual at 1.54.3 and Ubuntu's connectivity package at 1.54.3-2ubuntu3.1, not wire-checked: where network-manager-config-connectivity-ubuntu is installed (Ubuntu 26.04's desktop metapackages recommend it), NetworkManager sends a plain HTTP request to connectivity-check.ubuntu.com every 300 s while a network connection exists; enabled=false under [connectivity], in a file under /etc/NetworkManager/conf.d/, stops it, at the cost of captive-portal detection on hotel and café networks.

Builds and versions

the distro's packages network-manager and network-manager-config-connectivity-ubuntu, both 1.54.3-2ubuntu3.1On by default?yes · read in its config and its manualMeasured here?no · in the vendor's documentsDate checked (UTC)2026-10-10

Version: 1.54.3-2ubuntu3.1 · the Ubuntu 26.04 packages
Where the evidence came from: Ubuntu 26.04 desktop, x86-64 (a machine of ours, not a stock install)
On by default?: yes · read in its config and its manual: where Ubuntu's connectivity package is installed
Measured here?: no · in the vendor's documents
Date checked (UTC): 2026-10-10
Why we say so: NetworkManager.conf's manual at 1.54.3, and the Ubuntu connectivity package's config and install files at 1.54.3-2ubuntu3.1; the switch set over D-Bus and read back on a machine of ours

Each call out

connectivity check · 1.54.3-2ubuntu3.1

Version · build: 1.54.3-2ubuntu3.1 · the Ubuntu 26.04 packages · Ubuntu 26.04 desktop, x86-64 (a machine of ours, not a stock install) · the distro's packages network-manager and network-manager-config-connectivity-ubuntu, both 1.54.3-2ubuntu3.1
Sends by default: yes · read in its config and its manual: where Ubuntu's connectivity package is installed
Kind: checks
Trigger: on its own
When: Per its manual: every 300 s while a network connection exists (the default when no interval is set); the Ubuntu package sets the address. Not wire-checked.
Where: vendor API · connectivity-check.ubuntu.com
What it sends: a plain HTTP request to Ubuntu's check address (request)
The vendor's stated purpose: “This allows NetworkManager to detect whether or not the system can actually access the internet or whether it is behind a captive portal.” — NetworkManager.conf's manual at 1.54.3, 'connectivity section', read 2026-10-10
Grade and method: read · NetworkManager.conf's manual at 1.54.3, and the Ubuntu connectivity package's config and install files at 1.54.3-2ubuntu3.1; the switch set over D-Bus and read back on a machine of ours · read 2026-10-10
Receipts: the manual's connectivity section · the Ubuntu package that sets the address · the Ubuntu connectivity package's config: the check address · where that package installs it · Ubuntu 26.04's desktop metapackage recommends that package · and so does its minimal desktop metapackage

The switch

[connectivity] enabled=false

Accepted values: false
What it is: a setting in NetworkManager's configuration
Where it must be set: in a file under /etc/NetworkManager/conf.d/, or at run time over D-Bus · turn them off
Also turns off: captive-portal detection: the desktop no longer offers a login page on hotel or café networks
What turning it off costs: you lose captive-portal detection, and a device behind a portal is no longer ranked below one with real connectivity
Proof: set over D-Bus, read back; not wire-checked
For the call: connectivity check · 1.54.3-2ubuntu3.1

Listens beyond the machine, and other cloud features

Listens beyond the machine by default

n/a · network software: not a server you reach (1.54.3-2ubuntu3.1 the Ubuntu 26.04 packages)

Other cloud features

None found.

What it leaves on disk

Nothing we know of.

Brings in, and installed for you by

None on the register.

Credit

None recorded.

Vendor documents it? · public discussion

Vendor documents it?

connectivity check · 1.54.3-2ubuntu3.1: yes · Its manual describes the check, its default interval and the switch. · github.com · NetworkManager.conf.xml · read 2026-10-10