Eth0 no more?

#1

Post by PassTheAmmo » Wed, Feb 23, 2011, 4:24 PM UTC

Re: Eth0 no more?

#2

Post by javanix » Wed, Feb 23, 2011, 5:04 PM UTC

From the limitations section of the wiki page linked in the article:

Not all add-in cards have a method to expose their Linux interface name(s) to external port mapping. biosdevname may provide incorrect names for such. Discussions are ongoing on the netdev mailing list to standardize a method of exposing such mapping.

Seems like this would be kind of a deal-breaker for any wholesale move like this. I'd be fairly surprised if this got any widespread adoption anytime soon.

Re: Eth0 no more?

#3

Post by beoba » Wed, Feb 23, 2011, 5:06 PM UTC

Looks like this could solve the problem of network interfaces renaming themselves after reboots. Hooray!

Re: Eth0 no more?

#4

Post by eklitzke » Wed, Feb 23, 2011, 5:10 PM UTC

There was a pretty good discussion about this on LWN a while back, I recommend it to anyone who wants more information (both the commentary their, as well as the linked article): https://lwn.net/Articles/424859/

Re: Eth0 no more?

#5

Post by e1ven » Wed, Feb 23, 2011, 5:11 PM UTC

beoba wrote: post #3

Looks like this could solve the problem of network interfaces renaming themselves after reboots. Hooray!

There are a lot of other solutions to that. The Ububuntu one I favored in the 8.x era was /etc/iftab, it's a shame they retired it in favor of udev.

While udev is more universal, iftab felt elegant and unixy.

Re: Eth0 no more?

#6

Post by zdw » Wed, Feb 23, 2011, 5:14 PM UTC

Mac OS X and Linux are the only OS's that I'm aware of that put all ethernet nics in the same device namespace.

Everyone else has separate device namespaces for - you might have an fxp0 , rl0, hme0, etc. on any BSD or Solaris machine.

Rather than looking in /dev, they really ought to be parsing the output of ifconfig -a.

Re: Eth0 no more?

#7

Post by CrLf » Wed, Feb 23, 2011, 5:15 PM UTC

beoba wrote: post #3

Looks like this could solve the problem of network interfaces renaming themselves after reboots. Hooray!

Network interfaces should not rename themselves after reboots. On Red Hat derived distributions, the device name is tied to the MAC address of the interface, so it never changes.

On other distributions, "udev" accomplishes the same thing.

The only point when interface naming is arbitrary is at installation time, then it stays the same forever.

Not only this will add confusion by introducing a bunch of new names for network interfaces, it will also break applications that rely on them being called "ethX".

It will also make it impossible to manually assign names to interfaces. For instance, if you have a configuration that uses an embedded interface and you want to add another interface on a card, you can manually assign the same "ethX" name to it, but not if the names depend on the physical characteristics of the hardware.

Re: Eth0 no more?

#8

Post by CrLf » Wed, Feb 23, 2011, 5:18 PM UTC

zdw wrote: post #6

Mac OS X and Linux are the only OS's that I'm aware of that put all ethernet nics in the same device namespace. Everyone else has separate device namespaces for - you might have an fxp0 , rl0, hme0, etc. on any BSD or Solaris machine. Rather than looking in /dev, they really ought to be parsing the output of ifconfig -a .

Having all ethernet devices called "ethX" makes it much easier to parse the output of ifconfig and exclude any non-ethernet interfaces (tunnels and such).

Re: Eth0 no more?

#9

Post by onedognight » Wed, Feb 23, 2011, 5:22 PM UTC

javanix wrote: post #2

From the limitations section of the wiki page linked in the article: Not all add-in cards have a method to expose their Linux interface name(s) to external port mapping. biosdevname may provide incorrect names for such. Discussions are ongoing on the netdev mailing list to standardize a method of exposing such mapping. Seems like this would be kind of a deal-breaker for any wholesale move like this. I'd be fairly sur…

Looks like this https://fedoraproject.org/wiki/Features/ConsistentNetworkDev... is going to be the default in Fedora 15.

Re: Eth0 no more?

#10

Post by adobriyan » Wed, Feb 23, 2011, 5:29 PM UTC

CrLf wrote: post #7

beoba wrote: post #3

Looks like this could solve the problem of network interfaces renaming themselves after reboots. Hooray!

Network interfaces should not rename themselves after reboots. On Red Hat derived distributions, the device name is tied to the MAC address of the interface, so it never changes. On other distributions, "udev" accomplishes the same thing. The only point when interface naming is arbitrary is at installation time, then it stays the same forever. Not only this will add confusion by introducing a bunch of new names for n…

> Network interfaces should not rename themselves after reboots.

But that's because PCI bus walk order doesn't change across reboots.