Arch Linux

tickbehrouz

Member

Registered: 2014-07-11

Posts: 11

network problem at boot up

Hello everybody.
I have got a problem and I will be grateful if you have any suggestions.
I use a TPlink 8811 DSL modem with its USB port.
The default kernel has a driver for it (Broadcom I think). It was working OK at first but now after boot up I have to reattach the USB cable and also restart the dhcp service (and in this order!), to make the network running. I am not aware of any update that could cause this problem.
Any suggestion for tracing back the problem ?
(and I am kinda newbie, so please consider that!)
thanks a lot.

nixpunk

Member

Registered: 2009-11-23

Posts: 271

Re: network problem at boot up

It was working OK at first

Did you try rolling back to the kernel release where it was working?  That would be a good start in diagnosing the problem.

tickbehrouz

Member

Registered: 2014-07-11

Posts: 11

Re: network problem at boot up

it's odd!!
today, when I booted into arch the network was working. I am completely sure that I have not installed anything in recent days.

Did you try rolling back to the kernel release where it was working?  That would be a good start in diagnosing the problem.

Actually I have not upgraded my kernel . It's running on the kernel that I installed in the beginning.

tomk

Forum Fellow

From: Ireland

Registered: 2004-07-21

Posts: 9,839

Re: network problem at boot up

Your description of the issue is too vague, we can only guess what might be wrong. You need to check your journal and logs for clues.

Apart from that, why in God's name would you use usb here when that router has an ethernet connection??

tickbehrouz

Member

Registered: 2014-07-11

Posts: 11

Re: network problem at boot up

Your description of the issue is too vague, we can only guess what might be wrong. You need to check your journal and logs for clues.

Apart from that, why in God's name would you use usb here when that router has an ethernet connection??

Well I know that my descriptions are not any good, and sorry for that. Maybe it's because of my lack of knowledge.
I like to know where to start. For example after boot up, it should be working, and now that it's not, somewhere should be a log that what is wrong. That journal and logs that you mentioned, how can I find some information about them?
My question is: how can I distinguish that problem is related to USB driver or DHCP server?

And about the Ethernet connection!  my sister already use it and she is not planning on releasing it any time soon!!!

thanks

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 19,822

Re: network problem at boot up

...And about the Ethernet connection!  my sister already use it and she is not planning on releasing it any time soon!!!

Might I suggest treachery

What are the outputs of:

ip link
ip addr
uname -a
and
pacman -Qi linux

---

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

tomk

Forum Fellow

From: Ireland

Registered: 2004-07-21

Posts: 9,839

Re: network problem at boot up

And about the Ethernet connection!  my sister already use it and she is not planning on releasing it any time soon!!!

Get a cheap 4-port ethernet switch, and eradicate this usb networking nonsense from your life.

tickbehrouz

Member

Registered: 2014-07-11

Posts: 11

Re: network problem at boot up

Might I suggest treachery

What are the outputs of:

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: enp2s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
    link/ether 1c:6f:65:48:ff:cd brd ff:ff:ff:ff:ff:ff
3: enp0s18f0u2c2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
    link/ether d8:5d:4c:ef:d0:92 brd ff:ff:ff:ff:ff:ff

ip addr

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: enp2s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether 1c:6f:65:48:ff:cd brd ff:ff:ff:ff:ff:ff
    inet6 fe80::b1ac:d759:af39:509f/64 scope link tentative
       valid_lft forever preferred_lft forever
3: enp0s18f0u2c2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether d8:5d:4c:ef:d0:92 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::da5d:4cff:feef:d092/64 scope link
       valid_lft forever preferred_lft forever
    inet6 fe80::cd01:1b07:c38c:cb00/64 scope link
       valid_lft forever preferred_lft forever

uname -a

Linux archhost 3.15.5-1-ARCH #1 SMP PREEMPT Thu Jul 10 07:08:50 CEST 2014 x86_64 GNU/Linux
what is it good for?

pacman -Qi linux

Name           : linux
Version        : 3.15.5-1
Description    : The Linux kernel and modules
Architecture   : x86_64
URL            : http://www.kernel.org/
Licenses       : GPL2
Groups         : base
Provides       : kernel26=3.15.5
Depends On     : coreutils  linux-firmware  kmod  mkinitcpio>=0.7
Optional Deps  : crda: to set the correct wireless channels of your country
Required By    : virtualbox-host-modules
Optional For   : None
Conflicts With : kernel26
Replaces       : kernel26
Installed Size : 72735.00 KiB
Packager       : Tobias Powalowski <tpowa@archlinux.org>
Build Date     : Thu 10 Jul 2014 09:42:32 AM IRDT
Install Date   : Fri 11 Jul 2014 06:17:12 PM IRDT
Install Reason : Explicitly installed
Install Script : Yes
Validated By   : Signature

Is there anything unusual in this results? Actually I dont spot any !!
and one thing that maybe helpful. After boot up the "systemctl status dhcp.service" shows :

● dhcpcd.service - dhcpcd on all interfaces
   Loaded: loaded (/usr/lib/systemd/system/dhcpcd.service; enabled)
   Active: active (running) since Tue 2014-07-22 14:02:22 IRDT; 6min ago
  Process: 308 ExecStart=/usr/bin/dhcpcd -q -b (code=exited, status=0/SUCCESS)
Main PID: 312 (dhcpcd)
   CGroup: /system.slice/dhcpcd.service
           └─312 /usr/bin/dhcpcd -q -b

Jul 22 14:02:23 archhost dhcpcd[312]: enp2s0: waiting for carrier
Jul 22 14:02:23 archhost dhcpcd[312]: enp0s18f0u2c2: waiting for carrier
Jul 22 14:02:23 archhost dhcpcd[312]: enp0s18f0u2c2: carrier acquired
Jul 22 14:02:27 archhost dhcpcd[312]: DUID 00:01:00:01:1b:52:93:55:d8:5d:4c:ef:d0:92
Jul 22 14:02:27 archhost dhcpcd[312]: enp0s18f0u2c2: IAID 4c:ef:d0:92
Jul 22 14:02:27 archhost dhcpcd[312]: enp0s18f0u2c2: carrier lost
Jul 22 14:02:28 archhost dhcpcd[312]: enp0s18f0u2c2: soliciting a DHCP lease
Jul 22 14:02:29 archhost dhcpcd[312]: virbr0: adding address fe80::c431:897d:81ff:d387
Jul 22 14:02:29 archhost dhcpcd[312]: virbr0: waiting for carrier
Jul 22 14:02:29 archhost dhcpcd[312]: if_managelink: No such device or address

when I reattach the USB cable, it shows:
Jul 22 14:02:23 archhost dhcpcd[312]: enp0s18f0u2c2: waiting for carrier
Jul 22 14:02:23 archhost dhcpcd[312]: enp0s18f0u2c2: carrier acquired
Jul 22 14:02:27 archhost dhcpcd[312]: DUID 00:01:00:01:1b:52:93:55:d8:5d:4c:ef:d0:92
Jul 22 14:02:27 archhost dhcpcd[312]: enp0s18f0u2c2: IAID 4c:ef:d0:92
Jul 22 14:02:27 archhost dhcpcd[312]: enp0s18f0u2c2: carrier lost
Jul 22 14:02:28 archhost dhcpcd[312]: enp0s18f0u2c2: soliciting a DHCP lease
Jul 22 14:02:29 archhost dhcpcd[312]: virbr0: adding address fe80::c431:897d:81ff:d387
Jul 22 14:02:29 archhost dhcpcd[312]: virbr0: waiting for carrier
Jul 22 14:02:29 archhost dhcpcd[312]: iif_managelink: No such device or address
Jul 22 14:10:05 archhost dhcpcd[312]: ienp0s18f0u2c2: dhcp if_readrawpacket: Network is down

and after restarting the dhcp service it shows:

Jul 22 14:10:47 archhost dhcpcd[2932]: enp0s18f0u2c2: adding address fe80::cd01:1b07:c38c:cb00
Jul 22 14:10:47 archhost dhcpcd[2932]: forked to background, child pid 2933
Jul 22 14:10:48 archhost dhcpcd[2933]: enp2s0: waiting for carrier
Jul 22 14:10:48 archhost dhcpcd[2933]: enp0s18f0u2c2: waiting for carrier
Jul 22 14:10:48 archhost dhcpcd[2933]: enp0s18f0u2c2: carrier acquired
Jul 22 14:10:48 archhost dhcpcd[2933]: DUID 00:01:00:01:1b:52:93:55:d8:5d:4c:ef:d0:92
Jul 22 14:10:48 archhost dhcpcd[2933]: enp0s18f0u2c2: IAID 4c:ef:d0:92
Jul 22 14:10:48 archhost dhcpcd[2933]: enp0s18f0u2c2: soliciting a DHCP lease
Jul 22 14:10:48 archhost dhcpcd[2933]: enp0s18f0u2c2: offered 192.168.1.100 from 192.168.1.1
Jul 22 14:10:48 archhost dhcpcd[2933]: enp0s18f0u2c2: soliciting an IPv6 router

sorry for the long post and thanks for your help

tickbehrouz

Member

Registered: 2014-07-11

Posts: 11

Re: network problem at boot up

Get a cheap 4-port ethernet switch, and eradicate this usb networking nonsense from your life.

I guess you are right. I just thought struggling to get it working would be fun!!!

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 19,822

Re: network problem at boot up

Jul 22 14:10:48 archhost dhcpcd[2933]: enp0s18f0u2c2: offered 192.168.1.100 from 192.168.1.1

That is a good start, but I would have expected further messages about accepting the lease and adding routes. 
For now, what happens if you were to disable IPv6 ?

Also, please use BBCode code tags around program output.  Your readers will appreciate it.  There is also a link to the help under each post message box on the site.  Thanks.

---

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

tickbehrouz

Member

Registered: 2014-07-11

Posts: 11

Re: network problem at boot up

Also, please use code tags around ...

sorry for the inconvenience, I will use them from now on.

however unfortunately I can not reboot my system very often, so I will post the results as soon as possible.

thanks.

tickbehrouz

Member

Registered: 2014-07-11

Posts: 11

Re: network problem at boot up

...
For now, what happens if you were to disable IPv6 ?

well unfortunately disabling the IPv6 was no help to this situation.

Besides the same thing happened when I succeeded to get my hands on the Ethernet port! It needed a restart for dhcp.service to work.

I guess my lack of knowledge, impedes a deep and helpful investigation!

I think it would be good idea to install another tool, like network manager. Is it?

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 19,822

Re: network problem at boot up

As another data point, what if you try using dhclient instead of dhcpcd.?

---

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

tickbehrouz

Member

Registered: 2014-07-11

Posts: 11

Re: network problem at boot up

As another data point, what if you try using dhclient instead of dhcpcd.?

well unfortunately I couldn't get it to work, but I guess I have found a cure. So far the lts version of the kernel has not show any problems. I guess it wise to stick with it!
should I mark this thread as solved?!