iPhone USB tethering problems

[SimonLew]

Hi all, first post here. I'm setting up OpenPlotter and PyPilot as a pi learning exercise so am firmly in the noob category. USB tethering was working great. Updated all the charts and then it stopped. I mucked around with no luck, re-imaged the SD card and still no joy. The iPhone goes into USB tether mode and it is recognized by the pi. However there is no internet connection. I'm running headless with an iPad, no problems. I also have VNC Viewer installed on the iPhone and it connects over USB no problem, just no internet. Tried two different iPhones and cables so don't think it's an iPhone problem. Mystery is why a fresh image worked great the first time but, after it stopped working re-installing the same image on the same SD card no longer tethers. ifconfig printout below. Any help would be greatly appreciated.

eth0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether dc:a6:32:54:92:f0  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 172.20.10.4  netmask 255.255.255.240  broadcast 172.20.10.15
        inet6 fe80::a04e:a7ff:fe12:fd7  prefixlen 64  scopeid 0x20<link>
        inet6 2600:380:952c:9198:a04e:a7ff:fe12:fd7  prefixlen 64  scopeid 0x0<global>
        ether a2:4e:a7:12:0f:d7  txqueuelen 1000  (Ethernet)
        RX packets 443  bytes 214040 (209.0 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 714  bytes 75703 (73.9 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 1769  bytes 165401 (161.5 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1769  bytes 165401 (161.5 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlan9: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.10.10.1  netmask 255.255.255.0  broadcast 10.10.10.255
        inet6 fe80::dea6:32ff:fe54:92f1  prefixlen 64  scopeid 0x20<link>
        ether dc:a6:32:54:92:f1  txqueuelen 1000  (Ethernet)
        RX packets 35573  bytes 3007873 (2.8 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 27408  bytes 5985171 (5.7 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[holgerw]

in openplotter network on the right side under sharing select "auto" or "eth1" which is in your case the usb-iphone.
good luck.

holger

[SimonLew]

In openplotter network - sharing internet device dropdown I only see auto, eth0 and none. Auto does not work. Is the missing eth1 a clue as to what's going on?

[holgerw]

There is also an Problem with eth0, it has no IP-Adresse assiggned. Is there anything connected?

[e-sailing]

If the raspberry doesn't get internet when you have the ifconfig output as shown above, you have a route problem. It is independent of the sharing settings. What does route -a say?

[SimonLew]

There is nothing connected. My understanding is that eth0 is the physical ethernet port. Just checked it by plugging a cable in and an IP got assigned and internet works through the wired connection.

I got eth1 to show up in the sharing internet dropdown by having the iPhone connected to USB before powering up the pi. Selecting eth1 or Auto makes no difference, still no internet through USB tether.

Thanks for trying to help.

---

---

If the raspberry doesn't get internet when you have the ifconfig output as shown above, you have a route problem. It is independent of the sharing settings. What does route -a say?

Thanks for the tip on sharing settings. route -a says the following which is wayyyy over my head :-)

route: invalid option -- 'a'
Usage: route [-nNvee] [-FC] [<AF>]           List kernel routing tables
       route [-v] [-FC] {add|del|flush} ...  Modify routing table for AF.

       route {-h|--help} [<AF>]              Detailed usage syntax for specified AF.
       route {-V|--version}                  Display version/author and exit.

        -v, --verbose            be verbose
        -n, --numeric            don't resolve names
        -e, --extend             display other/more information
        -F, --fib                display Forwarding Information Base (default)
        -C, --cache              display routing cache instead of FIB

  <AF>=Use -4, -6, '-A <af>' or '--<af>'; default: inet
  List of possible address families (which support routing):
    inet (DARPA Internet) inet6 (IPv6) ax25 (AMPR AX.25) 
    netrom (AMPR NET/ROM) ipx (Novell IPX) ddp (Appletalk DDP) 
    x25 (CCITT X.25)

[SimonLew]

After some more mucking about, is this what you are looking for? route -v:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         172.20.10.1     0.0.0.0         UG    204    0        0 eth1
default         openplotter.loc 0.0.0.0         UG    510    0        0 wlan9
10.10.10.0      0.0.0.0         255.255.255.0   U     510    0        0 wlan9
172.20.10.0     0.0.0.0         255.255.255.240 U     204    0        0 eth1

[e-sailing]

It should be OK.
Can you
ping 172.20.10.1 (iphone)
ping 8.8.8.8 (google)
?

[SimonLew]

It should be OK.
Can you
ping 172.20.10.1  (iphone)
ping 8.8.8.8         (google)
?

ping 172.20.10.1 is good
ping 8.8.8.8 no reply

[e-sailing]

OK. I think you have updated your iphone from IOS 13 to IOS 14.
There was an issue with IOS 14 (https://discussions.apple.com/thread/251829006?page=3).
This should be fixed with Linux kernel 5.10 (see https://github.com/potato1992/Iphone_usb_tethering_fix).
You should update your Linux if uname -a is lower than 5.10.
sudo apt update
sudo apt upgrade
I can't test this, because I don't have IOS 14.