A start job is running for raise network interfaces (5 mins 1 sec) in ubuntu16.04

[physicist1616]

Don't feel bad... I started testing Ubuntu Server 16.04 today and this bit me too. And there is no Network Manager, so it is probably something in the new systemd network services. Sorry, but I do not have a fix yet.

The fix for Ubuntu Server is pretty simple: Change the line in /etc/network/interfaces that reads, "auto {Your ethernet adapter's name here}" to "allow-hotplug {Your ethernet adapter's name here}".
It's waiting for a DHCP reply, if my Wireshark-Fu is correct.

In my case, that looks like:

#Original Line
auto ens34
iface ens34 inet dhcp

#New line
allow-hotplug ens34
iface ens34 inet dhcp

It's reasonable to suggest that setting a static IP would do it too.

I don't know the equivalent in the GUI stuff.

If you are indeed rolling with a PC that is hotplugging ethernet (like a laptop), this is the most correct fix, as it informs the system that this network shouldn't be required on startup, and, if you wanted, you could still configure another network that is auto that *is* required on startup.

[nielsduelund]

That seems to be not just a workaround, but the actual solution. To me at least
It seems to me that this is the way that network connections used to work when specifying auto.

[arpaham]

The fix for Ubuntu Server is pretty simple: Change the line in /etc/network/interfaces that reads, "auto {Your ethernet adapter's name here}" to "allow-hotplug {Your ethernet adapter's name here}".
It's waiting for a DHCP reply, if my Wireshark-Fu is correct.

In my case, that looks like:

#Original Line
auto ens34
iface ens34 inet dhcp

#New line
allow-hotplug ens34
iface ens34 inet dhcp

It's reasonable to suggest that setting a static IP would do it too.

I don't know the equivalent in the GUI stuff.

If you are indeed rolling with a PC that is hotplugging ethernet (like a laptop), this is the most correct fix, as it informs the system that this network shouldn't be required on startup, and, if you wanted, you could still configure another network that is auto that *is* required on startup.

Thanks a lot!!
A have a Acer Netbook AspireOne and this one was the best solution for me.
Now everything works without that awful timeout countdown.

[glebaron2]

The fix for Ubuntu Server is pretty simple: Change the line in /etc/network/interfaces that reads, "auto {Your ethernet adapter's name here}" to "allow-hotplug {Your ethernet adapter's name here}".
It's waiting for a DHCP reply, if my Wireshark-Fu is correct.

In my case, that looks like:

#Original Line
auto ens34
iface ens34 inet dhcp

#New line
allow-hotplug ens34
iface ens34 inet dhcp

It's reasonable to suggest that setting a static IP would do it too.

I don't know the equivalent in the GUI stuff.

If you are indeed rolling with a PC that is hotplugging ethernet (like a laptop), this is the most correct fix, as it informs the system that this network shouldn't be required on startup, and, if you wanted, you could still configure another network that is auto that *is* required on startup.

This was the correct answer for me! A rather small but critical difference if you are installing the server version and you want to run it using dhcp.
I changed this setting and all the network flakiness disappeared.

[whit-launchpad]

Does anyone know the logic of wanting 5 minutes? That seems a crazy default -- especially when the default splash screen gives no indication of what's broken. What variety of network trouble would clear by itself after the first minute of waiting?

Thanks for the useful explanations here.

[houstonbofh]

Does anyone know the logic of wanting 5 minutes? That seems a crazy default -- especially when the default splash screen gives no indication of what's broken. What variety of network trouble would clear by itself after the first minute of waiting?

I have given up asking questions like that. Usually there is no answer. But sometimes there is an answer, and that is actually worse. (Like: We did it so it boots faster!)

[hawk291]

Thank you physicist1616, your solution helped me.

/etc/network/interfaces

#Original Line
auto ens34
iface ens34 inet dhcp

#New line
allow-hotplug ens34
iface ens34 inet dhcp