Oh no, you!

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Cake day: 2024年11月3日

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  • Unmanaged switches don’t care about VLAN tags, spanning trees, management interfaces, or LACP.

    Managed switches care about at least some of those features and therefore will have a management interface to configure them, as well as firmware supporting them.

    A dumb/unmanaged switch will look up the MAC address of the intended recipient and map that to a port before forwarding a packet to a particular port. A managed switch might do a lot more.

    If you don’t need a managed switch, don’t buy one. If you’re OK with everything on one port being able to communicate with anything on another port, and connectivity is your only concern, you’re probably going to be fine with an unmanaged switch.

    Source: I manage (amongst other things) managed switches for a living.






  • Yes, except no plugging involved: It’s some sort of inductive way of programming it via a USB dongle. The info is written into this “programming program” which can read and write data to the unit, it’s written, and then you read it to make sure all the info was applied.

    Then you label the unit physically with ship name, callsign, and MMSI. In addition to this there are two stickers that come with the unit, denoting the expiry date of the battery and the hydrostatic release. These go on the unit so that’s it easy to check if it’s time to replace them.



  • neidu3@sh.itjust.workstoxkcd@lemmy.worldxkcd #3169: EPIRBs
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    18 天前

    For those who didn’t know: EPIRB = Emergency Position Indicating Radio Beacon. Sends an emergency signal via satellite and terrestrial RF. They can be triggered manually, but they also trigger automatically if salt water shorts two exposed pads for a certain amount of time (a minute, I think).
    Once triggered it will get a GPS fix and transmit a distress signal via satellite as well as terrestrial VHF. It is programmed with the MMSI of the ship it belongs to.
    Works all over the world, although they take a bit longer to successfully transmit the signal in the polar regions as they then have to rely on LEO sattelots in polar orbits.

    Source: I have a GOC, and I also used to work with marine electronics. I’ve programmed hundreds of these. Mainly Jordan Jotron TR60 (Ducking autocorrect). Some from McMurdo too, don’t remember the model name.

    Fun fact: A coworker did have to make the phonecall of shame to the coastal radio after accidentally dropping one overboard.