OK to disable dhcpcd and use NetworkManager?

Amanda S · 2014-06-24 05:18:36

After a lot of research and testing, I came to the conclusion that NetworkManager will conflict with dhcpcd no matter what I do, no matter what configuration I try. Disabling dhcpcd, however, fixes everything related to my wired and VPN connections.

Is it really possible that NetworkManager wants to be the King of the Hill and deal with dhcpd stuff by itself? Is there any security issues using it alone with the dhcpcd module disabled?

fungle · 2014-06-24 05:42:49

I'm pretty sure NetworkManager works with dhclient. In fact I'm pretty sure that it defaults to dhclient if you have it installed. Try installing dhclient and see if that works.

Amanda S · 2014-06-24 05:58:33

fungle wrote:

I'm pretty sure NetworkManager works with dhclient. In fact I'm pretty sure that it defaults to dhclient if you have it installed. Try installing dhclient and see if that works.

It might work with it, but it works without it

It's not like NetworkManager won't work. It works, but with the dhcpcd module unloaded. That's my concern, it's towards not using dhcpcd.

fungle · 2014-06-24 06:10:01

Amarildo wrote:

It might work with it, but it works without it
It's not like NetworkManager won't work. It works, but with the dhcpcd module unloaded. That's my concern, it's towards not using dhcpcd.

That's interesting, are you using static IPs. I'm not quite sure how you get Network Manager working without a dhcp client.

Amanda S · 2014-06-24 06:11:59

fungle wrote:

That's interesting, are you using static IPs. I'm not quite sure how you get Network Manager working without a dhcp client.

Me neither. I'm using dynamic IP's.

Not that all the tests I'm doing are done in VirtualBox. I'll test it "for real" in the next minutes, I just have to finish watching a Nightwish documentary.

Last edited by Amanda S (2014-06-24 06:14:22)

cju · 2014-06-24 10:31:37

I can confirm your "issue", though, according to my point of view, it isn't a real one, since there's no need for two services for just one purpose, i.e. simply running/managing a network connection...

Nevertheless, NetworkManager should (and afaics does) run fine without things like dhcpcd or netctl enabled.

Trilby · 2014-06-24 10:55:24

There is a lot of ambiguity in this thread. Armadillo is referring to loading/unloading a dhcpcd module (there is no such thing!), fungle seems to be referring to installation/removal of packages for dhcpcd or dhclient, and cju is referring to enabling/disabling systemd services.

Armadillo, what are you actually asking? As mentioned, there is no module to load or unload. You do need the dhcpcd or dhclient packages installed as NetworkManager will use one of them. And that is the point: NetworkManager will call dhcpcd.

As all the networking wiki pages say, you should have only one networking service enabled. So if you've enabled NetworkManager, not only is it ok to disable dhcpcd, you are expected to - NetworkManager will not work properly with the dhcpcd service also enabled.

ozar · 2014-06-24 15:37:15

Trilby wrote:

As all the networking wiki pages say, you should have only one networking service enabled. So if you've enabled NetworkManager, not only is it ok to disable dhcpcd, you are expected to - NetworkManager will not work properly with the dhcpcd service also enabled.

lol... the last time I installed NetworkManager, it took me several hours to figure out that having dhcpcd enabled as a service was the cause of the continued network failure. I'll never forget the lesson learned again.

ooo · 2014-06-24 15:52:44

you can disable dhcpcd systemd service if using networkmanager. Actually you probably shouldn't have dhcpcd service enabled if using networkmanager.
networkmanager will use either dhcpcd or dhclient for retrieving your ip address, so having separate service for dhc* will probably only mess things up.

Amanda S · 2014-06-24 15:54:08

Trilby wrote:

There is a lot of ambiguity in this thread. Armadillo is referring to loading/unloading a dhcpcd module (there is no such thing!), fungle seems to be referring to installation/removal of packages for dhcpcd or dhclient, and cju is referring to enabling/disabling systemd services.
Armadillo, what are you actually asking? As mentioned, there is no module to load or unload. You do need the dhcpcd or dhclient packages installed as NetworkManager will use one of them. And that is the point: NetworkManager will call dhcpcd.
As all the networking wiki pages say, you should have only one networking service enabled. So if you've enabled NetworkManager, not only is it ok to disable dhcpcd, you are expected to - NetworkManager will not work properly with the dhcpcd service also enabled.

Actually, I think I mixed up two things: modprobe and systemctl. What I do is just "systemctl disable dhcpcd" so that I can enable NetworkManager in the same way, otherwise it won't work if dhcpcd is enabled. This is, for what I could see, not a kernel module, but a system service or daemon.
Well, it was almost 4am, I'm guilty.

I don't remove the dhcpcd package at all, I just stop/disable it with systemctl.

EDIT:

ooo wrote:

you can disable dhcpcd systemd service if using networkmanager. Actually you probably shouldn't have dhcpcd service enabled if using networkmanager.
networkmanager will use either dhcpcd or dhclient for retrieving your ip address, so having separate service for dhc* will probably only mess things up.

Thank you. I can sleep again

Last edited by Amanda S (2014-06-24 15:57:58)

Arch Linux

#1 2014-06-24 05:18:36

OK to disable dhcpcd and use NetworkManager?

#2 2014-06-24 05:42:49

Re: OK to disable dhcpcd and use NetworkManager?

#3 2014-06-24 05:58:33

Re: OK to disable dhcpcd and use NetworkManager?

#4 2014-06-24 06:10:01

Re: OK to disable dhcpcd and use NetworkManager?

#5 2014-06-24 06:11:59

Re: OK to disable dhcpcd and use NetworkManager?

#6 2014-06-24 10:31:37

Re: OK to disable dhcpcd and use NetworkManager?

#7 2014-06-24 10:55:24

Re: OK to disable dhcpcd and use NetworkManager?

#8 2014-06-24 15:37:15

Re: OK to disable dhcpcd and use NetworkManager?

#9 2014-06-24 15:52:44

Re: OK to disable dhcpcd and use NetworkManager?

#10 2014-06-24 15:54:08

Re: OK to disable dhcpcd and use NetworkManager?

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