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mindstalk

Member

Registered: 2014-05-16

Posts: 23

tethering not working on laptop [SOLVED]

[Edit: 'solved' via inadvertent kernel upgrade and reboot.  Quotes because it's not obvious to me what the problem was, but it's not an open problem. [Possibly explained in post #6: kernel upgrade without rebooting meant missing modules.]]

I know my phone's tethering works, it works with my eee, running some version of Ubuntu 10.04.  When I try with my new Arch laptop, with no wireless or wifi connection:

[Zefiris:0] ps -ef | grep dhc
root      6018     1  0 May15 ?        00:00:00 dhcpcd enp12s0
root      9308     1  0 00:14 ?        00:00:00 dhcpcd wlp2s0
damien    9385 15887  0 00:17 pts/2    00:00:00 grep dhc
[Zefiris:0] ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp12s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DEFAULT group default qlen 1000
    link/ether d4:be:d9:6b:7b:b1 brd ff:ff:ff:ff:ff:ff
3: wlp2s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DEFAULT group default qlen 1000
    link/ether 24:77:03:b9:b5:1c brd ff:ff:ff:ff:ff:ff

That's with the interface up; if I set it down, I get <BROADCAST,MULTICAST> for enp12s0 instead.

After killing process 6018:

$ sudo dhcpcd enp12s0
dhcpcd[5848]: version 6.3.2 starting
dhcpcd[5848]: enp12s0: waiting for carrier
dhcpcd[5848]: timed out
dhcpcd[5848]: exited

Help?

Last edited by mindstalk (2014-05-16 15:04:38)

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,354

Re: tethering not working on laptop [SOLVED]

Well, what kind of phone is it?  (iOS, Android)
Are using wireless or wired tethering?
Your dhcpcd example shows enp12s0, but I've a hunch that is a wired interface with an 8P8C connector.  When you attach a phone in wired tether mode, I would expect your system to spawn a fourth entry in the output of ip link.
If wireless, then we are way off course.

---

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Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
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mindstalk

Member

Registered: 2014-05-16

Posts: 23

Re: tethering not working on laptop [SOLVED]

Android.  Version 4.2.something, Galaxy S4 with little modification.
Wired, via USB cable.

enp12s0 is the interface for the ethernet cable.  But I gave the entire output of ip link; if it's supposed to spawn a fourth entry... then it's not.

...well, it wasn't.  After an accidental reboot I see a 5: usb0 in ip link, and putting wifi down has tethering take over.  Problem 'solved', I guess...

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,354

Re: tethering not working on laptop [SOLVED]

Any chance you had recently updated the kernel without having rebooted?
Anyway, if this is solved, don't forget to edit your first post and add [SOLVED] to the beginning of the thread title.

---

Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
---
How to Ask Questions the Smart Way

mindstalk

Member

Registered: 2014-05-16

Posts: 23

Re: tethering not working on laptop [SOLVED]

I think I had, yes.  Just pacman -Su in the past week or two.

Marked as solved for not being an open problem, though I don't understand what the problem was.

Last edited by mindstalk (2014-05-16 14:32:08)

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,354

Re: tethering not working on laptop [SOLVED]

My guess is that you had updated the kernel, but had not rebooted.  When you attached the phone, the running kernel could not find its modules as the modules had been replaced by those for the new kernel that you were not yet running.  No module, no network interface.

---

Nothing is too wonderful to be true, if it be consistent with the laws of nature -- Michael Faraday
Sometimes it is the people no one can imagine anything of who do the things no one can imagine. -- Alan Turing
---
How to Ask Questions the Smart Way

mindstalk

Member

Registered: 2014-05-16

Posts: 23

Re: tethering not working on laptop [SOLVED]

Ah, that sounds plausible.  Pretty sure that the upgrade happened before the tethering attempt, yes.