[Bug 38578] Re: Enable interface does not acquire address from DHCP

[Luka Renko]

Problem is that knetworkconf considers interface without IP address as down (even if it is up) and therefore Enable interface fails as ifup will return immedeatley with error.
I will fix the code to not consider such interface as down and therefore you will be able to do Disable interface, followed by Enable interface to acquire the address. 
I hope this works for you.

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Enable interface does not acquire address from DHCP
https://launchpad.net/bugs/38578