[SOLVED] NetworkManager does not start dhcpcd

gphilip · 2011-09-01 09:17:06

I installed Arch Linux for the first time a couple of days back on my laptop, and am currently in the process of adding various facilities which I need.

I am connected to the internet by a wired connection (eth0). Today I tried adding dnsmasq for its DNS cache facility (and also to set up internet sharing later). At some point during this process, the nm-applet icon developed a "cross", indicating "No network connection". Further, I lost my internet connection as well (I noticed both of these when I tried to google something later).

Left-clicking on the nm-applet icon showed : "Wired network : disconnected". Clicking on the name of the wired network resulted in NetworkManager trying to connect ("hourglass"-ish icon) for a long time, but then failing to connect.

I tried restarting (nm-applet, NetworkManager, and then the computer), but that didn't work. After a bit of investigation, I found the following:

1. The eth0 interface was up, but it had no IP address.
2. Running "dhcpcd eth0" worked : eth0 got the correct IP address, and I was able to connect to the internet.
3. Even after eth0 was connected as above, the nm-applet icon said "no network connection".

I am currently browsing in this state : NM thinks eth0 is not connected, but it is connected, and is using an IP address which I got by manually invoking dhcpcd.

I investigated a bit further, and the following seems to be the problem --- NM is not starting dhcpcd by itself:

 
$ ps -aef |grep Net
root      6686     1  0 14:13 ?        00:00:00 /usr/sbin/NetworkManager
user   6887  6777  0 14:35 pts/2    00:00:00 grep Net

$ ps -aef |grep dhc
root      6716     1  0 14:13 ?        00:00:00 dhcpcd eth0
user   6889  6777  0 14:35 pts/2    00:00:00 grep dhc

I seem to remember that NetworkManager was earlier being started with a number of arguments, unlike the first snippet above. Also, googling around for this issue, I found that people usually have the other complaint : that NM starts dhcpcd by itself, and thus goes and overwrites their customized /etc/resolv.conf . This somehow does not seem to happen now for me:

$ cat /etc/resolv.conf 
# Generated by dhcpcd from eth0
# /etc/resolv.conf.head can replace this line
domain local.lan
nameserver 192.168.1.1
# /etc/resolv.conf.tail can replace this line

To summarize, my problem is that the NetworkManager instance started on system startup does not invoke dhcpcd. As a result, when I log in there is no internet available by my wired connection.

Could you help me with troubleshooting this?

Thanks,
Philip

Last edited by gphilip (2011-09-02 15:52:21)

cbowman57 · 2011-09-01 10:09:21

Try adding this to /etc/rc.local

dhcpcd -k eth0 
dhcpcd -nd eth0

Make you you make the appropriate change if you're on something other than eth0

(That's straight from the wiki BTW)

Last edited by cbowman57 (2011-09-01 10:09:56)

gphilip · 2011-09-01 16:04:28

@cbowman57 :

Thank you, that workaround partially fixed my problem : I can now connect to the internet via eth0 after rebooting, without having to manually run dhcpcd eth0.

However, NetworkManager still does not recognize the connection : It says the wired network is disconnected, and does not show eth0 as an option either.

Thanks again for your help.

cbowman57 · 2011-09-01 16:12:44

Ok, you're running networkmanager 0.9.0-1? What networkmanager-dispatcher are you running, and it's version?

gphilip · 2011-09-01 18:15:04

Yes, I am running networkmanager 0.9.0-1 .

I am not running networkmanager-dispatcher :

$ pacman -Q networkmanager 
networkmanager 0.9.0-1
$ pacman -Q networkmanager-dispatcher
error: package "networkmanager-dispatcher" not found

Should I be running this as well?

There does not seem to be a networkmanager-dispatcher available in the repostories which I use. There are some variants, though:

# pacman -S network <TAB><TAB>
networkmanager                      networkmanager-dispatcher-sshd
network-manager-applet              networkmanager-openconnect
networkmanager-dispatcher-netfs     networkmanager-openvpn
networkmanager-dispatcher-ntpd      networkmanager-pptp
networkmanager-dispatcher-openntpd  networkmanager-vpnc
# pacman -S networkmanager-dispatcher
error: target not found: networkmanager-dispatcher

Last edited by gphilip (2011-09-01 18:17:59)

cbowman57 · 2011-09-01 18:23:46

Really not certain, I've got networkmanager-dispatcher-ntpd but pretty sure that's just network time protocol. I don't use wireless so can't verify anything regarding that. What happens if you execute network-admin or nm-connection-editor from the command line?

gphilip · 2011-09-01 18:31:03

network-admin gives "Command not found".

nm-connection-editor opens the NM connection editor (which I can also open by right-clicking on the NM applet). There are no wired connections listed there, which is a bit weird since I am typing this over eth0.

cbowman57 · 2011-09-01 18:36:43

Hmm.. network-admin must be part of another package, it doesn't come up in a query. Not sure if that's part of the missing link or not.

$ pacman -Qs network
local/glib-networking 2.28.7-4
    Network-related giomodules for glib
local/gnome-nettool 3.0.0-1 (gnome-extra)
    A Collection of GNOME3 Networking Tools.
local/krb5 1.9.1-3
    The Kerberos network authentication system
local/mobile-broadband-provider-info 20110511-1
    Network Management daemon
local/networkmanager 0.9.0-1
    Network Management daemon
local/network-manager-applet 0.9.0-1
    GNOME frontends to NetWorkmanager
local/networkmanager-dispatcher-ntpd 1.0-1
    Dispatcher Script for ntpd
local/nss 3.12.11-3
    Mozilla Network Security Services
local/ntp 4.2.6.p3-3
    NTP (Network Time Protocol) tries to keep servers in sync
local/ppp 2.4.5-2 (base)
    A daemon which implements the Point-to-Point Protocol for dial-up networking
local/syslog-ng 3.2.4-3 (base)
    Next-generation syslogd with advanced networking and filtering capabilities
local/wget 1.13.1-1 (base)
    A network utility to retrieve files from the Web
local/wpa_supplicant 0.7.3-3 (base)
    A utility providing key negotiation for WPA wireless networks

This is everything I have installed with "network" in it & everything seems to work as it should.

Last edited by cbowman57 (2011-09-01 18:43:21)

gphilip · 2011-09-02 15:51:27

In the end the fix turned out to be something quite silly!

Inspired by this post on the Ubuntu help forums, I went and created a new eth0 connection (this was missing during the time when I had this problem), and now everything works fine : NM identifies the connection, starts dhcpcd on eth0 at boot time with all the wierd parameters, and merrily overwrites my /etc/resolv.conf :

ps -aef |grep dhc
root       958   840  0 21:10 ?        00:00:00 /sbin/dhcpcd -B -K -L -G -c /usr/lib/networkmanager/nm-dhcp-client.action eth0
user   1873  1686  0 21:18 pts/0    00:00:00 grep dhc
$ cat /etc/resolv.conf 
# Generated by NetworkManager
domain local.lan
search local.lan
nameserver 192.168.1.1

Thanks for all the help!

cbowman57 · 2011-09-02 15:53:39

Glad you found the solution and let us know what it was.

Seems like no matter what the solution is we always feel silly after the fact.

Cadeyrn · 2013-06-25 06:40:41

Could you explain the process you went through to accomplish that? I have the same problem, and I'm Googling "linux make new network interface". I'm not finding anything about actually making a new interface, and I'm afraid of borking my internet if I try.

At first I thought you meant making a new connection within the NM applet's configuration, but that didn't fix it for me.

Last edited by Cadeyrn (2013-06-25 06:42:23)

fsckd · 2013-06-25 12:41:28

Cadeyrn, please start a new thread. This thread is old and the situation may have changed. Furthermore, the other participants have not been around in a long time. See also, Forum Etiquette: Old Threads / Necro-Bumping. Good luck.
Closing.

Arch Linux

#1 2011-09-01 09:17:06

[SOLVED] NetworkManager does not start dhcpcd

#2 2011-09-01 10:09:21

Re: [SOLVED] NetworkManager does not start dhcpcd

#3 2011-09-01 16:04:28

Re: [SOLVED] NetworkManager does not start dhcpcd

#4 2011-09-01 16:12:44

Re: [SOLVED] NetworkManager does not start dhcpcd

#5 2011-09-01 18:15:04

Re: [SOLVED] NetworkManager does not start dhcpcd

#6 2011-09-01 18:23:46

Re: [SOLVED] NetworkManager does not start dhcpcd

#7 2011-09-01 18:31:03

Re: [SOLVED] NetworkManager does not start dhcpcd

#8 2011-09-01 18:36:43

Re: [SOLVED] NetworkManager does not start dhcpcd

#9 2011-09-02 15:51:27

Re: [SOLVED] NetworkManager does not start dhcpcd

#10 2011-09-02 15:53:39

Re: [SOLVED] NetworkManager does not start dhcpcd

#11 2013-06-25 06:40:41

Re: [SOLVED] NetworkManager does not start dhcpcd

#12 2013-06-25 12:41:28

Re: [SOLVED] NetworkManager does not start dhcpcd

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