I have an update here, in case anyone else is having this problem. Thanks to @dukla2000 for the idea to run `nmtui`.
What I did is run `sudo nmtui`, then edit the USB connection, and for the IPv4 connection, set it to 'Shared'. Then I went back to the main nmtui screen, then to 'Activat a connection', select USB, and then selevt 'Activate'.
This will not work if the IPv4 connection is set to 'Automatic'. If I try to activate the connection nmtui will say 'connection not available on device usb0 because device has no carrier'.
If I exit out of nmtui, and run ip addr show usb0, now I'll see:
```
usb0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
link/ether 42:70:fe:6c:09:71 brd ff:ff:ff:ff:ff:ff
inet 10.66.0.1/24 brd 10.66.0.255 scope global noprefixroute usb0
valid_lft forever preferred_lft forever
inet6 fe80::f137:ad8:84ea:8aef/64 scope link tentative noprefixroute
valid_lft forever preferred_lft forever
```
If I'm already SSHed into the phone, I can run ssh mobian@10.66.0.1 and ssh back into myself on that IP. however, I can't ssh to 10.66.0.1 from my computer. I can't even ping it.
I should also point out that if I have the wifi off on my phone and I try to ssh to it over lan, it'll say 'no route to host'. But when I connect my phone to the computer with USB, and then try to connect, it just hangs at the CLI and does nothing. Not sure if that's relevant.
What I did is run `sudo nmtui`, then edit the USB connection, and for the IPv4 connection, set it to 'Shared'. Then I went back to the main nmtui screen, then to 'Activat a connection', select USB, and then selevt 'Activate'.
This will not work if the IPv4 connection is set to 'Automatic'. If I try to activate the connection nmtui will say 'connection not available on device usb0 because device has no carrier'.
If I exit out of nmtui, and run ip addr show usb0, now I'll see:
```
usb0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
link/ether 42:70:fe:6c:09:71 brd ff:ff:ff:ff:ff:ff
inet 10.66.0.1/24 brd 10.66.0.255 scope global noprefixroute usb0
valid_lft forever preferred_lft forever
inet6 fe80::f137:ad8:84ea:8aef/64 scope link tentative noprefixroute
valid_lft forever preferred_lft forever
```
If I'm already SSHed into the phone, I can run ssh mobian@10.66.0.1 and ssh back into myself on that IP. however, I can't ssh to 10.66.0.1 from my computer. I can't even ping it.
I should also point out that if I have the wifi off on my phone and I try to ssh to it over lan, it'll say 'no route to host'. But when I connect my phone to the computer with USB, and then try to connect, it just hangs at the CLI and does nothing. Not sure if that's relevant.