MySQL authentication success depends on interface speed

    I've been using LE with a common MySQL database for over a decade and have a standard advancedsettings.xml file which I copy across to each new system. When trying to setup a new Raspberry Pi 4, LE failed to connect to the MariadB database on my Synology server to populate the library display. Weirdly, after manually browsing files on the server a connection would sometimes be established and everything would behave normally. After a reboot however the connection was lost again. Browsing the log files shows that authentication is failing at startup for all tables in the database.

    I tried to pinpoint the problem at the packet level using Wireshark on the PC - connecting the Rpi to a second (USB, 10/100) ethernet interface and bridging it to the main PC interface (Not straightforward BTW). Surprisingly, LE authenticated quite happily so I was then unable to record the problem.

    I then plugged the 10/100 interface into the Rpi4 and used that instead of the built-in interface to connect to my GbE router - LE again authenticated properly.

    It appears that the RPi4 will not authenticate to MariadB when connected using GbE all the way to the server. Inserting a 10/100 throttle seems to get around the problem - but will then restrict the media traffic to 100Mbit/s at best.

    Platform:

    • LibreELEC-RPi4.arm-11.0.6 & LibreELEC-RPi4.aarch64-12.0.2
    • Hardware Platform: Raspberry Pi 4, 4Gb

    The problem is local to your network or hardware and is not a general issue. I'm highly confident of that due to a) using RPi4 and RPi5 boards myself to connect to a Synology NAS over Gbit Ethernet (both on the same Gbit switch) without issue, and b) the large number of daily active RPi4 installs and no other users reporting similar issues.

    Suggestions:

    • Update RPi4 firmwares
    • Use different switch ports
    • Use different cables
    • Test an LE13 nightly

    Good call! I just discovered that the GbE port on my wall is only connecting at 100Mbit/s - the cable must have a broken wire somewhere. Connecting to a tested working port restores the usual expected behaviour. Very weird that the crippled connection transmits apparently error-free data for playing movies etc. but always refuses to authenticate the database on startup.


    Thanks

    Just been in my loft and mice have chewed a number of cables - and in this case broken the brown wire!!!!! I'd better test all the others. :rolleyes:

    Edited once, last by dickh: Merged a post created by dickh into this post. (June 4, 2025 at 5:23 PM).