4 ms·

USB is ubiquitous, proven, and reliable but you are welcome to use RS485.

fragmede 2y ago
In the days since RS485, OTA firmware flashing's become the standard, though we could also go back to EEPROMs with the little UV window. Those were the days.
- mulmen 2y ago
  I’m honestly laughing out loud that I have to explain why I don’t want OTA updates on my network hardware.
  - yjftsjthsd-h 2y ago
    I can think of reasonable reasons to not want OTA (it makes some ways of persisting a compromise hard). Now, do you understand why some people very much do want OTA updates, especially on network hardware? (I'll give you mine for free: I want to minimize time and effort required to patch security bugs.)
    - mulmen 2y ago
      Are we mixing terminology? OTA means over the air as in wifi. If I need a firmware update I’ll do it from the management console on a wired network, preferably on a dedicated interface or vlan.
      - yjftsjthsd-h 2y ago
        Okay, then yes we're using the same term to mean different things. I mostly see "OTA" used to describe Android devices downloading updated system images via whatever network they happen to be on at the moment, but I view it as meaning any update installed over the network, ex. iOS updating over LTE, a laptop running apt-get over wifi, or a server pulling .rpm files over fiber from the cache server 3 racks over. And yes, I suppose that last one doesn't literally have "air" in play, but I don't really see a conceptual difference; you can run SSH over wireguard over wifi and LTE and I think that can be at least as secure as plugging a serial cable into the box directly. Obviously the details depend on your threat model, but I really don't think it's likely to matter that much. For a lot of things running openwrt in particular, I'd actually prefer that updating not involve me plugging in a direct line - because ideally the device would auto-update and reboot on a schedule with zero human interaction required, so you get security patches without manual effort. (And a robust A/B + self-test setup or whatever to make that safe.)
        mulmen 2y ago
        I don’t want my management network exposed to wifi or the internet. OTA as you have described it requires both.
alanfranz 2y ago
You probably mean rs232 anyway, I see no reason for an rs485 network here.

In the days since RS485, OTA firmware flashing's become the standard, though we could also go back to EEPROMs with the little UV window. Those were the days.

mulmen 2y ago
I’m honestly laughing out loud that I have to explain why I don’t want OTA updates on my network hardware.
- yjftsjthsd-h 2y ago
  I can think of reasonable reasons to not want OTA (it makes some ways of persisting a compromise hard). Now, do you understand why some people very much do want OTA updates, especially on network hardware? (I'll give you mine for free: I want to minimize time and effort required to patch security bugs.)
  - mulmen 2y ago
    Are we mixing terminology? OTA means over the air as in wifi. If I need a firmware update I’ll do it from the management console on a wired network, preferably on a dedicated interface or vlan.
    - yjftsjthsd-h 2y ago
      Okay, then yes we're using the same term to mean different things. I mostly see "OTA" used to describe Android devices downloading updated system images via whatever network they happen to be on at the moment, but I view it as meaning any update installed over the network, ex. iOS updating over LTE, a laptop running apt-get over wifi, or a server pulling .rpm files over fiber from the cache server 3 racks over. And yes, I suppose that last one doesn't literally have "air" in play, but I don't really see a conceptual difference; you can run SSH over wireguard over wifi and LTE and I think that can be at least as secure as plugging a serial cable into the box directly. Obviously the details depend on your threat model, but I really don't think it's likely to matter that much. For a lot of things running openwrt in particular, I'd actually prefer that updating not involve me plugging in a direct line - because ideally the device would auto-update and reboot on a schedule with zero human interaction required, so you get security patches without manual effort. (And a robust A/B + self-test setup or whatever to make that safe.)
      - mulmen 2y ago
        I don’t want my management network exposed to wifi or the internet. OTA as you have described it requires both.

alanfranz 2y ago

You probably mean rs232 anyway, I see no reason for an rs485 network here.