iPhone/iOS 11 tether via USB - no packets routed [SOLVED]

[Punchcutter]

I'm trying to tether my iPhone 5s/iOS 11.1.2 to my Gentoo laptop via USB (I had been trying to use wifi, but ran into other troubles and gave up when I realized I could maybe do it with an actual wire). I followed instructions found on the wiki and it all went very smoothly and seems fine from a kernel perspective. I won't bother showing you the evidence of that

I've got a new interface created and made an node for it in /etc/init.d in the usual way. Personal Hotspot is turned on. I learned that I needed to turn off LTE on the phone in order to fix the fact that I wasn't seeing any DHCP server. Turning off LTE fixed that and then I got what looks like a proper IP address and everything seems in order. The phone shows a blue bar at the top that says "Personal Hotspot: 1 connection":

[Punchcutter]

Gack.... ok that problem was caused by the firewall #smh. I should have figured that out quicker. But I'm going to leave this thread open a bit longer to see if I can get any help with the following...

So now... packets can route to the phone side, and there's no apparent problem with DNS, but.... now there's still no response from the outside world. I can try to load pages in the browser, and they eventually time out. So it's like I'm talking to the world, but no one is answering. Aaaugh! I know... the farther this gets from being a straightforward technical problem, the less chance anyone will have a clue that can help me, but... I'll grasp at straws a bit and hope. Thanks.

(I did neglect to mention that I am running a VPN on the phone, but that shouldn't cause any trouble because the phone itself can access the web just fine, and I tried testing with the VPN turned off and of course it didn't make a difference.)

[bunder]

if this were iptables, it still sounds like fw/routing... eg

[Punchcutter]

[bunder]

[Zucca]

[Punchcutter]

[Punchcutter]

[Punchcutter]

OK, so I've discovered that although browsers keep spinning and spinning and eventually time out, I can telnet to a web server, and GET a page that way. So now this seems to make little sense to me. The following yields results:

[Punchcutter]

So, long story short, I've spent hours on this problem since the last post... and many many minutes over a few different calls with Apple support, and also once the engineering dept of my cell provider....... and last night it finally started to work for "no apparent reason". But I figured out what the trigger was.

When I first tried this tether, the laptop was not getting an IP addr via DHCP. I googled about that. Someone on some forum suggested that this happens if you have "LTE" turned on on the phone. So I went into the iPhone cell data settings and turned off "Enable LTE". After that, DHCP worked fine. So I thought, "Ok, I need to keep LTE turned off."

But then I reached the abovementioned problem, whereby I could communicate across the tether with IP sites, including web servers and nameservers, but the only thing I could NOT do was receive web data back from a web server when the client doing the requesting looks like a browser. In other words, if I try to pull a web site using an actual browser, or curl, I can connect to the server side, but I then hang/timeout waiting while no data is returned. On the other hand, if I use telnet to do the same thing, I can get the page data back. Utterly bizarre.

Through all the time spent trying to debug THAT problem, I never went back and questioned the LTE thing, or tried flipping it back on during my testing. When I did finally turn it back on..... now suddenly DHCP still works, and tethering works fully and I can surf the web. Maybe the second strangest thing about this whole episode is why DHCP didn't work originally until I turned LTE off on the phone, but now it does work with LTE active. In between those two events, I did (on advice from Apple support) do a hard reset on the phone. Maybe that "shook something loose". Geh. Problems like this are so frustrating. Just glad it finally works. BTW, I did go back and test again to see if having the LTE switch on or off really made the difference. Yep, LTE off, web page data does not flow back to browsers or curl, but does for telnet. LTE on, everything works fine. Go figure.

Hope this helps someone else.

[babagau]

It's a two year old post but I still want to say "thank you, it helped me". I factory restored only the networking of my iPhone5 and now wpa_supplicant works, can connect through the iphone to the internet. Punchcutter by the way I love your english.
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