RPi installs w/ Ethernet AND WiFi very flaky: (1) disconnects all ssh sessions (2) forces auto-creation of unwanted hotspot

[holta]

CONTEXT: No matter what we tell people, it's an extremely common situation for a PC/RPi to be connected to both Ethernet and WiFi when its IIAB install begins. Then things go a bit haywire, and we can do better!

So @jvonau is helping try to resolve this on 10.8.0.58 = 192.168.0.142/lan = 192.168.0.100/wifi that has (should, until we run iiab-hotspot-on) have both Ethernet and WiFi gateways:

root@box:~# more /etc/iiab/openvpn_handle
142-rpi3bp-desktop-feb25-WIFI

Patterns...all of which are repeatable on 7.0/master:

• Every time you run ./iiab-network, ssh output freezes at TASK [network : Restart hostapd when WiFi is present] even while it does in fact complete behind the scenes, according to /opt/iiab/iiab/iiab-network.log (implementer should not be left high+dry like this)
• ssh fails to BOTH 192.* local addresses, Ethernet & Wi-Fi (let's fix this!)
• ssh to OpenVPN address (on the WAN side) works about 30-50% of the time, freezing screen output every minute or less, and dropping the ssh connection every minute or so (let's fix this!)
• hotspot is forcibly re-created by ./iiab-network even when the implementer has asked to turn it off using iiab-hotspot-off ...is this what we really want?? (implementer's expressed desire should not be overruled, however we do this!)
• ssh to 192.168.0.142/ethernet can be restored using a reboot (but this should not be nec)
• ssh to 192.168.0.100/wifi can be restored using iiab-hotspot-off (but this should not be nec, right?)

Background...this is how you confirm the hotspot is on:

root@box:~# brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.b827eb555ed2       no              wlan0

Background...this is how you confirm hotspot if off:

root@box:~# brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.000000000000       no

Might take a couple days to (re)solve these...such that output/instructions are crystal clear for new implementers as is a central goal here...however we work this out (not unreasonably all implementers ask: "just tell me what is happening, so I know my options" :-)

Refs: #796 #1519 #1520 PRs #697 #748 #1453 #1523 #1525 #1526

[holta]

ssh to 192.168.0.142/ethernet can be restored using a reboot (but this should not be nec)

FYI this is exact same problem occurs when running iiab-hotspot-on on an RPi / Rasp Lite that did NOT have an Ethernet cord during its original IIAB installation (e.g. 10.8.0.38 = 192.168.0.143) — the ability to ssh in over Ethernet is blocked, until the next boot.

Whereas iiab-hotspot-off does not clobber the ability to ssh over Ethernet on 10.8.0.38 here.

[holta]

ssh to 192.168.0.142/ethernet can be restored using a reboot (but this should not be nec)

FYI this is exact same problem occurs when running iiab-hotspot-on on an RPi / Rasp Lite that did NOT have an Ethernet cord during its original IIAB installation (e.g. 10.8.0.38 = 192.168.0.143) — the ability to ssh in over Ethernet is blocked, until the next boot.

Turns out this is not always true on 143-rpi3bp-lite-feb26-MIN-WIFI. Specifically, the Ethernet stays alive after running iiab-hotspot-on if the machine was booted with the Ethernet inserted. Thanks to @jvonau who suspected this, which I've now confirmed, just FYI.

(Anyway this ticket is principally about 142-rpi3bp-desk-feb25-WIFI+WIFI which continues to fail in the several ways described at the top of this ticket.)

[jvonau]

resolved with either the latest master or #2337