No more network connection

gerald82 · 2014-04-01 09:36:14

Hello,

recently -- after checking the arch front page for important notes and troubles I might encounter -- I ran a full system upgrade, which I do roughly every two weeks. As usual, I expected a flawless update without problems. First, it seemed to be like that.
However, after rebooting I realized I had no more network connection. I have used a simple, wired network setup.

Now I'm a little embarrassed, because with the help of the wiki I was able to maintain my arch box for years now and also had no problem with the "bigger" changes in the last few years, but now I'm clueless.
I did go through the networking sections in the beginners' guide, but to no avail unfortunately.

What information can I provide here so that anyone could help me?

Something that seems not important to me, but maybe I am wrong about that: I uninstalled the kdeplasma-networkmanager package right after the system upgrade.

For the time being, I do not need wireless connections or something, I only want to establish a wired internet connection.
I can provide logs and everything, but do not know which ones are relevant. Can you please help?

(Other than networking, everything worked fine after the upgrade)

Void_Walker · 2014-04-01 10:21:56

show us

ip addr

and

lspci | grep net

or simple lspci if the former does not return something.
I am just guessing that maybe the netwok card is down and that we might need it to start up again.

If the problem is only in getting the IP, the try to run

dhcpcd

which should assign an IP to your network interface (if it is up and if you have a dhcp on your network.

Last edited by Void_Walker (2014-04-01 10:22:14)

Slithery · 2014-04-01 10:26:01

Try re-installing kdeplasma-networkmanager, you should still have a copy in your pacman cache so no need to be online to do it.

gerald82 · 2014-04-02 11:42:53

Void_Walker wrote:

show us
ip addr
and
lspci | grep net
or simple lspci if the former does not return something.
I am just guessing that maybe the netwok card is down and that we might need it to start up again.
If the problem is only in getting the IP, the try to run
dhcpcd
which should assign an IP to your network interface (if it is up and if you have a dhcp on your network.

Thanks for the aid!

[root@argos ~]# 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: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 48:5b:39:9b:25:f5 brd ff:ff:ff:ff:ff:ff
    inet6 2a02:8070:d1b5:ea00:4a5b:39ff:fe9b:25f5/64 scope global dynamic 
       valid_lft 6913sec preferred_lft 3313sec
    inet6 fe80::4a5b:39ff:fe9b:25f5/64 scope link 
       valid_lft forever preferred_lft forever
3: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether 48:5d:60:84:9f:2f brd ff:ff:ff:ff:ff:ff

[root@argos ~]# lspci | grep net
06:00.0 Ethernet controller: Qualcomm Atheros AR8131 Gigabit Ethernet (rev c0)

Running dhcpcd was my first idea, but it doesn't seem to do anything.

[root@argos ~]# dhcpcd
dhcpcd[2028]: sending commands to master dhcpcd process

Nothing changed.

slithery wrote:

Try re-installing kdeplasma-networkmanager, you should still have a copy in your pacman cache so no need to be online to do it.

I tried that, too, but didn't help.
However I noticed that the package networkmanager was reinstalled in the process.
Could there be some conflict between networkmanager and dhcpcd?

magum · 2014-04-02 13:39:27

There is no ip address asssigned to your default network interface eth0. And the dhcpcd seems to be running.

How about killing the process and restarting it?
kill

> sudo killall dhcpcd
> ps -ef | grep dhcpcd
> sudo dhcpcd eth0

The output of the second command should be empty. Otherwise kill it with 'kill -9 <pid>'

gerald82 · 2014-04-02 15:35:53

magum wrote:

There is no ip address asssigned to your default network interface eth0. And the dhcpcd seems to be running.
How about killing the process and restarting it?
kill
The output of the second command should be empty. Otherwise kill it with 'kill -9 <pid>'

Doesn't show any effect. The output of

ip addr

is the same afterwards.
Actually, it looks like it gets an IPv6 adress, but not an IPv4 address?!

ewaller · 2014-04-02 16:02:34

You did not tell us much about your network other than it is simple and wired.
It would appear to me, there may not be a DHCP server running on the network. Where would such a server live on your network? Have you a router that provides that service? Which one? Have you tried rebooting the router?

gerald82 · 2014-04-02 16:23:07

You're right, ewaller. DHCP is provided by my FritzBox router. It has been rebooted multiple times since then. I don't think the router is the problem, since any other device (wired and wireless) in the network gets a DHCP lease, and so does my Arch box when I boot into a live system from DVD for instance.

pappix · 2014-04-02 21:04:25

Don't know if it might help, but AFAIK networkmanager and dhcpcd have conflict issues, I would uninstall networkmanager.

pappix · 2014-04-02 21:06:55

I mean that network manager activate dhcpcd, thus there might be two dhcpcd deamons concurring for the same resource?

ewaller · 2014-04-02 21:24:43

Please post the complete output of sudo dhcpcd -d

gerald82 · 2014-04-03 06:13:17

Right after rebooting it shows as follows:

[root@argos ~]# dhcpcd -d
dhcpcd[2955]: sending commands to master dhcpcd process
dhcpcd[2955]: send OK

Then I killed the dhcpcd process, restart it and repeat:

[root@argos ~]# dhcpcd -d     
dhcpcd[3089]: version 6.3.2 starting
dhcpcd[3089]: wlan0: up_interface: Operation not possible due to RF-kill
dhcpcd[3089]: eth0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' PREINIT
dhcpcd[3089]: eth0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' CARRIER
dhcpcd[3089]: wlan0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' PREINIT
dhcpcd[3120]: wlan0: starting wpa_supplicant
dhcpcd[3123]: wlan0: failed to start wpa_supplicant
dhcpcd[3124]: wlan0: Successfully initialized wpa_supplicant
Line 1062: unknown EAP method 'SIM'
You may need to add support for this EAP method during wpa_supplicant
build time configuration.
See README for more information.
Line 1062: failed to parse eap 'SIM'.
Line 1065: failed to parse network block.
Line 1072: unknown EAP method 'PSK'
You may need to add support for this EAP method during wpa_supplicant
build time configuration.
See README for more information.
Line 1072: failed to parse eap 'PSK'.
Line 1076: failed to parse network block.
Line 1108: unknown EAP method 'IKEV2'
You may need to add support for this EAP method during wpa_supplicant
build time configuration.
See README for more information.
Line 1108: failed to parse eap 'IKEV2'.
Line 1111: failed to parse network block.
Failed to read or parse configuration '/etc/wpa_supplicant/wpa_supplicant.conf'.
dhcpcd[3089]: wlan0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' NOCARRIER
dhcpcd[3089]: DUID 00:01:00:01:1a:c3:1b:b4:48:5b:39:9b:25:f5
dhcpcd[3089]: eth0: IAID 39:9b:25:f5
dhcpcd[3089]: eth0: soliciting an IPv6 router
dhcpcd[3089]: eth0: sending Router Solicitation
dhcpcd[3089]: eth0: reading lease `/var/lib/dhcpcd/dhcpcd-eth0.lease'
dhcpcd[3089]: eth0: discarding expired lease
dhcpcd[3089]: eth0: soliciting a DHCP lease
dhcpcd[3089]: eth0: sending DISCOVER (xid 0xdb5a0f53), next in 4.1 seconds
dhcpcd[3089]: wlan0: waiting for carrier
dhcpcd[3089]: eth0: Router Advertisement from fe80::2665:11ff:fe00:5316
dhcpcd[3089]: eth0: adding address 2a02:8070:d187:b500:4a5b:39ff:fe9b:25f5/64
dhcpcd[3089]: eth0: vltime 7200 seconds, pltime 3600 seconds
dhcpcd[3089]: eth0: adding route to 2a02:8070:d187:b500::/64
dhcpcd[3089]: eth0: adding default route via fe80::2665:11ff:fe00:5316
dhcpcd[3089]: eth0: executing `/usr/lib/dhcpcd/dhcpcd-run-hooks' ROUTERADVERT
dhcpcd[3089]: forking to background
dhcpcd[3089]: forked to background, child pid 3178

magum · 2014-04-03 08:58:58

What if you run dhcpcd with -4 option to enforce ipv4 usage? (Kill the running instance first.)

dhcpcd -4 -d eth0

Otherwise there are three different steps you could take:
1. Disable ipv6 on your machine.

2. Downgrade dhcpcd, which solved the issue in a older post.

3. Or deactivate the ipv6 dhcp functionality in your fritzbox. (Resource here in german)

ewaller · 2014-04-03 14:45:01

In addition to magum's suggestions. could you post the output of dhcpcd -U eth0
You could try bringing out the big guns and removing all files in /var/lib/dhcpcd and trying again. Those are all the lease files -- I am suggesting you nuke all the leases so dhcpcd has to start from scratch.

Not a solution, but you might also try dhclient instead of dhcpcd. It might get you going, and will give us another data point in diagnosing dhcpcd

gerald82 · 2014-04-11 13:09:36

Sorry for not replying so long, I was on a journey and could not work on the problem. I really appreciate the help, though.

I just downgraded the dhcpcd package to version 6.3.1-2 and when this didn't help I downgraded further to version 6.2.1-1. This also did not help.

However, it did change something: When I try to get an IPv4 lease with either of these two versions, it says that the DHCP servers offers an address, which fits into my IP network, i.e. a valid address. It also states the correct IP address of the DHCP server (the router).
However, dhcpcd does not accept the address, but times out and exits after like 10 seconds.
Any clue?

Arch Linux

#1 2014-04-01 09:36:14

No more network connection

#2 2014-04-01 10:21:56

Re: No more network connection

#3 2014-04-01 10:26:01

Re: No more network connection

#4 2014-04-02 11:42:53

Re: No more network connection

#5 2014-04-02 13:39:27

Re: No more network connection

#6 2014-04-02 15:35:53

Re: No more network connection

#7 2014-04-02 16:02:34

Re: No more network connection

#8 2014-04-02 16:23:07

Re: No more network connection

#9 2014-04-02 21:04:25

Re: No more network connection

#10 2014-04-02 21:06:55

Re: No more network connection

#11 2014-04-02 21:24:43

Re: No more network connection

#12 2014-04-03 06:13:17

Re: No more network connection

#13 2014-04-03 08:58:58

Re: No more network connection

#14 2014-04-03 14:45:01

Re: No more network connection

#15 2014-04-11 13:09:36

Re: No more network connection

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