Changing the IP address in NetworkManager should immediately change the IP on the interface

[Richard Laager]

Changing the IP address on a manually configured Ethernet interface and clicking OK does not result in the IP on the interface actually changing. You have to unplug the cable and plug it back in. When changing the IP address, NetworkManager should change the IP on the interface (running the down/up interface scripts as appropriate).

[Martin Mai (mrkanister-deactivatedaccount-deactivatedaccount)]

Thank you for taking time to report this. Please don't confirm your own bugs. Could you please add the /var/log/syslog to your bug report as an attachment? Also you can submit more information for it by looking to https://wiki.ubuntu.com/DebuggingNetworkManager , Thanks in advance.

[Richard Laager (rlaager)]

Please don't mark bugs Incomplete with canned responses unrelated to the issue at hand. (Nothing in DebuggingNetworkManager is relevant here.)

This is trivial for anyone with a network connection to test. It has been confirmed on multiple machines by myself and a co-worker. There is nothing written to /var/log/syslog when you change the IP and close the dialogs. Unless this actually works for you or someone else, I'd imagine NetworkManager has no code to do this. As I said, everything works fine if you force the connection down and up again.

[Timothy Smith (tas50)]

This same root issue also leads to an issue where when the user changes a network from manual to DHCP they must unplug / plug the cable or run dhclient manually.

[Martin (ub71-martin)]

I can confirm this bug on a fresh ubuntu 10.04.4 (lucid). All you have to do to reproduce is installing, open network manager, set static ip adress and you'll see that you are disconnected (and never connected back on the new static IP).

It means in clear, that if you need to change the ip adress remotely, you're busted.

I followed instructions for debug ( https://wiki.ubuntu.com/DebuggingNetworkManager#Getting_NetworkManager_debug_logs )

I get the following error.

$ sudo python debug-helper.py --nm debug
[sudo] password for sound4:
Setting NetworkManager log level to 'debug'
Traceback (most recent call last):
  File "debug-helper.py", line 37, in <module>
    nm.SetLogging(args.do_set_nm_logging, ','.join(args.log_domains))
  File "/usr/lib/pymodules/python2.6/dbus/proxies.py", line 68, in __call__
    return self._proxy_method(*args, **keywords)
  File "/usr/lib/pymodules/python2.6/dbus/proxies.py", line 140, in __call__
    **keywords)
  File "/usr/lib/pymodules/python2.6/dbus/connection.py", line 620, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.UnknownMethod: Method "SetLogging" with signature "ss" on interface "org.freedesktop.NetworkManager" doesn't exist

PS: I am running the fresh install from virtualbox.

[Martin (ub71-martin)]

What is important to notice is nothing more is happening in syslog when tweaking again network manager properties.

The only way to get the new settings applied is:
1) right-clic on network applet, uncheck / check "enable networking"
2) unplug / plug the network cable.

[Mathieu Trudel-Lapierre (cyphermox)]

The process is wrong. It's expected behavior that the settings don't change immediately; since you can change the settings to any connection, not just the active one, and nm-applet needs to speak to NM to change the settings.

What you'll want to do is edit the connection settings, then click on the connection itself again via nm-applet: for instance, if it's a Wifi network, click its name again just above the "disconnect" menu entry and the connection will be re-established.

Since this is already covered in NetworkManager, I'll close this bug as Fix Released.

[Mathieu Trudel-Lapierre (cyphermox)]

Well, actually won't fix in this case because the title is "should change immediately", which is explicitly what I describe above as something we don't want to do.

[Richard Laager (rlaager)]

Who expects this behavior? I would expect that when I'm editing the active connection, the changes are applied immediately. That fact that I can edit inactive connections is not relevant to how it should behave when I'm editing an active connection.

[Martin (ub71-martin)]

@Richard: I think I understand what Mathieu mean. At least, I see a case where it can be useful: imagine you want to reconfigure the box ip adress remotely. You may don't want it to be applied immediately, but for example at next reboot.
So from my point of view, there should be a "apply now" AND "apply at next reboot".

At least, If the expected behavior for the settings isn't to change immediately , it should be notified and specified to the user.

Mathieu, what do you think ?

[Martin (ub71-martin)]

Based of the expected behavior described by Mathieu, there is still an issue within the Live mode of ubuntu (Live CD/USB).
Basically , in this mode, changing from DHCP (default) to static and clic "apply..." effectively applies changes _immediatly_ (which is not expected base on Mathieu note).
Then, making change again is working like expected.

Do I have to open another issue for that ?

[Martin (ub71-martin)]

Sorry, I was not 100% complete in the previous note: when you change to static and clic "apply..." for the first time in Live mode, *something* happen immediately which leads the box to be disconnected from the network. So new changes are not effectively applied. Then , While disconnected, the check "enable networking" (right-clic on applet) is still and well checked. To recover network you have to LEFT-clic on applet, and select auto-eth0 to enable the interface again.

There is something strange about that.