Bug 499604

Summary: KDE connect doesn't find any devices. Error sending UDP packet; Failed to open any MDNS client/server sockets
Product: [Applications] kdeconnect Reporter: jfb <jfredericoberner>
Component: commonAssignee: Albert Vaca Cintora <albertvaka>
Status: REPORTED ---    
Severity: normal CC: andrew.g.r.holmes, kreutzer.peter, nicolas.fella
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: firewalld kdeconnect configurations

Description jfb 2025-02-06 17:07:36 UTC 
Created attachment 178024 [details]
firewalld kdeconnect configurations

SUMMARY
Haven't been able to connect any devices via kdeconnect, either via bluetooth or wi-fi. Followed the steps in the troubleshooting page of the KDEconnect wiki to no results.

I use KDEneon and firewalld (v2.1.1) has the proper port exceptions. 

Output of netcat -z -v <my-phone-ip> 1714-1716
Connection to <myphoneip> 1716 port [tcp/*] succeeded!

Output of netstat -tunelp | grep -i kdeconnect
tcp6       0      0 :::1716                 :::*                    LISTEN      1000       11758018   65038/kdeconnectd   
udp        0      0 0.0.0.0:45501           0.0.0.0:*                           1000       11753369   65038/kdeconnectd   
udp        0      0 0.0.0.0:5353            0.0.0.0:*                           1000       11758019   65038/kdeconnectd   
udp        0      0 0.0.0.0:48982           0.0.0.0:*                           1000       11753371   65038/kdeconnectd   
udp6       0      0 :::36985                :::*                                1000       11753373   65038/kdeconnectd   
udp6       0      0 :::5353                 :::*                                1000       11758020   65038/kdeconnectd   
udp6       0      0 :::46740                :::*                                1000       11753370   65038/kdeconnectd   
udp6       0      0 :::56560                :::*                                1000       11753372   65038/kdeconnectd   
udp6       0      0 :::1716                 :::*                                1000       11758017   65038/kdeconnectd

Output of journalctl --user --unit=app-org.kde.kdeconnect.daemon@autostart.service
fev 05 11:51:51 jfb kdeconnectd[3146]: 2025-02-05T11:51:51 default: Error sending UDP packet: QAbstractSocket::NetworkError
-- Boot cad84d817ea8441fa37a1db870eb198b --
fev 05 12:50:40 jfb systemd[2558]: Starting app-org.kde.kdeconnect.daemon@autostart.service - KDE Connect...
fev 05 12:50:40 jfb systemd[2558]: Started app-org.kde.kdeconnect.daemon@autostart.service - KDE Connect.
fev 05 12:50:41 jfb kdeconnectd[3279]: 2025-02-05T12:50:41 default: Error sending UDP packet: QAbstractSocket::NetworkError
fev 05 12:50:41 jfb kdeconnectd[3279]: 2025-02-05T12:50:41 kdeconnect.core: Failed to open any MDNS client sockets
fev 05 12:50:41 jfb kdeconnectd[3279]: 2025-02-05T12:50:41 kdeconnect.core: Failed to open any MDNS server sockets
fev 06 11:32:19 jfb kdeconnectd[3279]: 2025-02-06T11:32:19 default: Error sending UDP packet: QAbstractSocket::NetworkError
fev 06 13:34:24 jfb systemd[2558]: app-org.kde.kdeconnect.daemon@autostart.service: Consumed 1.011s CPU time.


OBSERVED RESULT
No devices are listed as available on KDEconnect.

EXPECTED RESULT
List of phones connected to the network and/or bluetooth should be present.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: KDE Neon 6.2
KDE Plasma Version: Plasma 6.2.5
KDE Frameworks Version: 6.10.0
Qt Version: 6.8.1
Comment 1 kreutpet 2025-12-14 10:15:36 UTC 
i do have same issue with KDE connect 25.08.01 on my laptop and KDE connect 1.34.4
on the laptop i do get "Error sending UDP packet: QAbstractSocket::NetworkError"