Ubuntu Finally Looks To Go With Persistent Network Interface Names

[FuturePilot]

I thought this was already the case? I installed 14.10 on a new server I built a while ago and got a p3p1 interface. Unless they're doing something different on the desktop?

[Ardje]

The horrors of udev... I got a lot of problems with my vlan package (actually, I never did had any problems because I wasn't using udev). The udev maintainers thought it was a good idea to base name persistence on MAC address... And each new vlan device had of course the same mac-address.
And the idea to base it on mac-address. I always have the persistent net rules disabled, and have devices numbered according to the pci slot or other bus characteristics.
I even name my usb tty devices according to their usb slot or bus number or any other thing that can identify the device.
Anyway: mac address have always been a bad idea. They can be invalid, or double or random or whatever other reason. And you can see in the rules that only for some high end IBM machines the udev rules are based on physical slot and not some random mac.
It's nice that things are starting to make sense upstream after 9 years or so.

The next thing is the configuration of the interface based on layers... I've yet to see a configuration that talks about configuring a physical interface, then adds protocols to that interface like ipv4 and ipv6 or another interface layer. I know of no distribution that allows reconfiguring your ipv6 without disturbing ipv4, or that allows stoping and starting a dhcp v4 client on an interface without down and upping the interface or a dhcp client that does not down the interface when ipv4 fails.
If I create several layers of virtual devices (maybe on top of a physical device), I want none of those devices to have ipv6 autoconfiguration or ipv4 arp handling, unless I tell it to. As far as I know, only the developers of openwrt are that far that they want to fix that (ifnetd and such, it's not yet fixed, but the idea is there).

[Ansla]

The previous way that Ubuntu was handling ifnames was the best solution currently possible. It works just fine on real hardware and regular VMs, only cloud providers had issues with it. But cloud providers use custom images anyway, so why not let them change the default in their image so it works fine for everybody? With this so called "predictable" names I get a random name for the wlan interface every time I connect it, depending on the USB port I use.

[rdnetto]

It seems like the real issue is that there's no support for defining an alias for a NIC. With block devices, /dev/disk/by-uuid/1234-1234-1234-1234 is just a symlink to /dev/sda1, so you can use whichever is more convenient. (e.g. the UUID in fstab, and sda1 when you're typing commands directly into the terminal). If that feature existed, then it would simply be a matter of defining some udev rules to create appropriate aliases and then you could continue to refer to wlp0s26u1u1 as wlan1, etc.