Although I see here and there that SSH over USB is not possible with RPi 3, it seems that SSHing over USB is possible for RPi 0.
This seems weird to me.
Do you (dis)confirm that SSH over USB is possible with RPi 0 but not with RPi 3?
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1confirmed. Although re – Dirk Dec 01 '18 at 14:55
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@Dirk Thanks. What do you mean with "Although re"? – hartmut Dec 01 '18 at 14:59
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Aah. Hit enter at the wrong moment ;) – Dirk Dec 01 '18 at 15:04
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1I should have added that this is because of gadget/slave mode. Only Pi0 (and derivatives) and Pi A/3A support this. The others don't because they have an onboard USB hub – Dirk Dec 01 '18 at 15:07
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This seems weird to me.
It's for the same reason you cannot connect the USB ports on your laptop to your desktop and use SSH over that.
USB is not a symmetrical protocol, meaning the two parties in a relationship are not equals. One is the master, and one is the slave. This is controlled in hardware, and although I believe it would be pretty simple to make a standard USB A port serve either role, conventionally they do not, I presume to prevent accidents, since plugging a master into a master can cause physical damage to one or both machines -- which is why you should never plug an A port into another A port (male-to-male cables for which are in fact hard to find).
Anyway, USB type micro-B ports are often implemented as OTG, meaning they can be used as either master or slave. This is how the one on the Pi zero works. SSH, which is TCP/IP based, is possible in that context when the Zero is configured to behave like an ethernet link.
goldilocks
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