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Eth0 no more?

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Re: Eth0 no more?

#31

Post by nailer »

rdtsc wrote: post #28
nailer wrote: post #21

Earlier quoted context omitted.

The first time the OS boots, the MAC addresses in ifcfg files are generated. Subsequent cold starts only read the files, they do not write them.

That is the the problem I am trying to convey -- the machines are coldstarted often and MAC addresses are reshufled on every first boot. If your cable to the management network is connected to left socket on the motherboard, that left socket needs to be eth0 on every coldstart. Sometimes it is not. "Yes" after the first boot when ifcfg files has been written it will be stable, but that mean someone has to go and eith…

> No they don't. Thare no files to read. You just wrote above in your commetn [sic] that the first time OS boots ifcfg are generate [sic]. So after a machine is coldstarted there are no ifcfg files!

As long as you don't reinstall your OS, or lose your data, your config files are there. Cold starting hardware does not delete data.

Are you trolling?

Re: Eth0 no more?

#32

Post by _b8r0 »

I can understand why people will resist this, thinking that somehow renaming eth0 to em0 or similar will break stuff, but here's the rub: It'll only break stuff that's badly written.

There's a right way to enumerate network interfaces and a wrong way (which is dependent on the language you're using for enumeration - the wrong way is assuming that eth0 is the only network device).

Bear in mind that the new convention is not entirely dissimilar to how WiFi cards have worked on Linux for some time, so the only things that will break will be things that:

    a) Assume eth0 instead of enumerating devices
    b) Have a legitimate reason for using eth0 only (I can't think of one, but I wouldn't be surprised if one existed)

Re: Eth0 no more?

#33

Post by nailer »

zdw wrote: post #26
ominous_prime wrote: post #24

Earlier quoted context omitted.

somewhat OT: > 2. You mean (IIRC) 'ip link show'. ifconfig on linux isn't maintained, and breaks in a bunch of situations (Aliases on VLANs on bonds, for one) This seemingly simple change seems to be taking forever to gain traction; "use `ip` for network config on linux". There is so much googlable stuff instructing one to use ifconfig, route, etc. that it seems to self perpetuate. I often find people telling others…

It's not that it self-perpetuates, it's that nearly every other Unix does it that way, and thus there's an expectation that ifconfig, if it exists, has similar functionality on all platforms. If you're going to deprecate a command, make running the old one either: 1. Not exist, and thus have the shell throw an "command not found" error 2. Print a useful message like "Use instead" 3. Work, but do #2 as well. The curre…

Yeah, the Linux distros (which themselves obviously only use 'ip') should have done #2 10 years ago.

When I worked at Red Hat (till 2005) their official RHCE documentation still told people to use ifconfig and route.

Re: Eth0 no more?

#34

Post by rdtsc »

nailer wrote: post #31
rdtsc wrote: post #28

Earlier quoted context omitted.

That is the the problem I am trying to convey -- the machines are coldstarted often and MAC addresses are reshufled on every first boot. If your cable to the management network is connected to left socket on the motherboard, that left socket needs to be eth0 on every coldstart. Sometimes it is not. "Yes" after the first boot when ifcfg files has been written it will be stable, but that mean someone has to go and eith…

> No they don't. Thare no files to read. You just wrote above in your commetn [sic] that the first time OS boots ifcfg are generate [sic]. So after a machine is coldstarted there are no ifcfg files! As long as you don't reinstall your OS, or lose your data, your config files are there. Cold starting hardware does not delete data. Are you trolling?

> Cold starting hardware does not delete data.

Alright, figured it out. When you talk about coldstaring you really mean restarting the machine, as in pressing the reset button for example. When I talk about coldstarting I mean starting with a bare hardware box and installing an OS on it.

> Are you trolling?

Actually I thought you were. Sorry for the misunderstanding.

[EDIT: I won't edit my previous posts, otherwise your posts won't make sense, let others laugh at my bad English (it is a 3rd language so I don't mind)]

Re: Eth0 no more?

#35

Post by samuel1604 »

From a quick look on a fresh ubuntu small server install it does not seem there is much that reference eth* scheme :

  ~$ sudo egrep -Irl 'eth[0-9]' /etc /usr 2>/dev/null |wc -l
  27

Re: Eth0 no more?

#36

Post by sciurus »

d135-1r43 wrote: post #25

I assume any consumer OS will generate a symlink for compatibility reasons.

Network interfaces aren't files, so you can't create symlinks to them. I don't think linux has a facility for referring to a network interface by more than one name.

My hope is that consumer distributions will stop presenting the device name and configuration at all. When I'm trying to show new Ubuntu users how to connect to wired and wireless networks, it's annoying to have to explain what NetworkManager means by "Auto eth0".

https://bugs.launchpad.net/ubuntu/+source/network-manager/+b...

Re: Eth0 no more?

#37

Post by ominous_prime »

zdw wrote: post #26
ominous_prime wrote: post #24

Earlier quoted context omitted.

somewhat OT: > 2. You mean (IIRC) 'ip link show'. ifconfig on linux isn't maintained, and breaks in a bunch of situations (Aliases on VLANs on bonds, for one) This seemingly simple change seems to be taking forever to gain traction; "use `ip` for network config on linux". There is so much googlable stuff instructing one to use ifconfig, route, etc. that it seems to self perpetuate. I often find people telling others…

It's not that it self-perpetuates, it's that nearly every other Unix does it that way, and thus there's an expectation that ifconfig, if it exists, has similar functionality on all platforms. If you're going to deprecate a command, make running the old one either: 1. Not exist, and thus have the shell throw an "command not found" error 2. Print a useful message like "Use instead" 3. Work, but do #2 as well. The curre…

I agree wholeheartedly that the old tools should be hidden away, and I assume that they haven't been, because that will break more things than the actual renaming of devices. I bet even adding deprecation warnings could cause a ruckus, seeing how many times I've come across `ifconfig | something` both in scripts and people shelling out from other languages. I do wish the distros would just make a clean break, and let people fix their crappy code.

Re: Eth0 no more?

#39

Post by [deleted] »

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 .

[deleted]

Re: Eth0 no more?

#40

Post by nl »

_b8r0 wrote: post #32

I can understand why people will resist this, thinking that somehow renaming eth0 to em0 or similar will break stuff, but here's the rub: It'll only break stuff that's badly written. There's a right way to enumerate network interfaces and a wrong way (which is dependent on the language you're using for enumeration - the wrong way is assuming that eth0 is the only network device). Bear in mind that the new convention…

Documentation that references eth0 isn't badly written.
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