Must of munged something in network connection

[Rocket J Squirrel]

Ubuntu 12.04 using the LXDE desktop. We have a mixed wired and wireless network here, and I prefer to give wired devices fixed IP addresses. Most of the machines are Windows and assigning fixed IP addresses on them is easy, but I've run into trouble doing so on this 12.04 box.

I edited /etc/network/interfaces to read:

auto loiface lo inet loopback


auto eth0
iface eth0 inet static
        address 192.168.1.110
        netmask 255.255.255.0
        gateway 192.168.1.1
        dns-nameservers 8.8.8.8 192.168.1.1

And rebooted the machine. The edit seems to have performed the desired function: the IP address is now 192.168.1.110. Ifconfig returns:

admin@CCD6:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:13:20:c5:eb:0e  
          inet addr:192.168.1.110  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::213:20ff:fec5:eb0e/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:4548 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2818 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3462392 (3.4 MB)  TX bytes:419965 (419.9 KB)


lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:12 errors:0 dropped:0 overruns:0 frame:0
          TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:720 (720.0 B)  TX bytes:720 (720.0 B)

But there used to be a little icon on the toolbar in the lower right corner, showing a plugged-in Ethernet connection, it's now gone. Network Connections doesn't show anything under the "Wired" tab. And right-clicking where the little icon used to be brings up:

[x] Enable Network
Connection Information
Edit Connections

"Connection Information" says "no valid active connections found"

AND YET I am presently connected to the Internet else I could not send this.

So clearly I've done a Bad Thing. Thoughts?

[Iowan]

I've been away from the networking side for awhile. At least a few versions ago, Network Manager would not touch interfaces configured via /etc/network/interfaces. The interface still got configured, but NM played dumb. There should be an option to make NM deal w/ the interface.
Another option: You should be able to set a fixed address via Network Manager.

I presume it's a typo that

auto lo
iface lo inet loopback

became

auto loiface lo inet loopback

[Bucky Ball]

Yep, Edit Connections and do it via Network Manager.

[Rocket J Squirrel]

Yep, Edit Connections and do it via Network Manager.

B-but, Edit Connections displays the same screen as Network Manager: Neither show anything under the "Wired" tab.

I presume it's a typo thatauto lo
iface lo inet loopback


became
auto loiface lo inet loopback

Yup. When I paste things between the CODE tags, they often display (after submitting) with lf/cr's missing.

[steeldriver]

If you define an interface via /etc/network/interfaces, then it will disappear from the network manager applet - they are separate services, and the network-manager service is configured by default to ignore interfaces from the networking service ('[ifupdown] managed=false')

[Rocket J Squirrel]

Steeldriver -- thanks for that explanation.

Question: if a fellow wants to assign a static IP address, is there a way to do that in a way that doesn't cause NM to go "hands off"?

[steeldriver]

Yes - just go to Edit Connections... on the main menu --> select the connection you want the static address for (Wired or Wireless) --> Edit --> IPv4 Settings tab and change the drop down from Automatic (DHCP) to Manual - then add the desired static IP (and other info such as DNS if appropriate)

[Rocket J Squirrel]

Yes - just go to Edit Connections... on the main menu --> select the connection you want the static address for (Wired or Wireless) --> Edit --> IPv4 Settings tab and change the drop down from Automatic (DHCP) to Manual - then add the desired static IP (and other info such as DNS if appropriate)

Seriously? I don't know why I didn't consider that right away. I just Googled around and found various hand-edits for /etc/network/interfaces to force a static IP.

Shoot. Okay, now that Network Manager no longer wants to have anything to do with managing the network, because I hand-edited /etc/network/interfaces, how do I get NM to forgive me and be willing to play again?

How about just returning it to its original condition, reading

auto lo
iface lo inet loopback

[steeldriver]

yes that should do it - you may need to restart the service(s) after reverting the file

sudo service networking restart
sudo service network-manager restart

(or just reboot)

[Bucky Ball]

Yes - just go to Edit Connections... on the main menu --> select the connection you want the static address for (Wired or Wireless) --> Edit --> IPv4 Settings tab and change the drop down from Automatic (DHCP) to Manual - then add the desired static IP (and other info such as DNS if appropriate)

Exactly.