Device naming for wireless NICs...

Device naming for wireless NICs...

[James Ketrenos]

If this topic been hashed a lot already, please let me know the keywords I might 
search for in the archives to find the threads.

I've had a few requests by users of the IPW2100 wireless driver to switch the 
default interface name to be wlanX vs. ethX.  In my prior searches through the 
wireless drivers in the 2.6.3 kernel tree, I couldn't find any that changed from 
the default.

I don't mind adding a module parameter to change the default name (if that is 
the standard practice), but thought I'd see what others thing rather than just 
going off and doing something random.

Is there a technical or ease of use reason switching away from ethX?  My 
thinking in keeping it eth was that it then represents a greater chance of "just 
working" with most networking scripts and utilities that may assume ethX is the 
interface name.

Thanks,
James

Re: Device naming for wireless NICs...

[Tomasz Torcz]

On Thu, Mar 11, 2004 at 10:28:23AM -0600, James Ketrenos wrote:
> I don't mind adding a module parameter to change the default name (if that 
> is the standard practice), but thought I'd see what others thing rather 
> than just going off and doing something random.

 This could be handled by nameif in userspace.
 
> Is there a technical or ease of use reason switching away from ethX?  My 
> thinking in keeping it eth was that it then represents a greater chance of 
> "just working" with most networking scripts and utilities that may assume 
> ethX is the interface name.

 I personally find them broken. I had to remove checking the name from
ethtool to make it work. Ethtool checks for 'eth' or 'usb' in name,
which do not work with my e1000 renamed to 'ep0'.

-- 
Tomasz Torcz                Only gods can safely risk perfection,     
zdzichu@irc.-nie.spam-.pl     it's a dangerous thing for a man.  -- Alia

Re: Device naming for wireless NICs...

[Matthew Galgoci]

On Thu, 11 Mar 2004, James Ketrenos wrote:

> 
> If this topic been hashed a lot already, please let me know the keywords I might 
> search for in the archives to find the threads.
> 
> I've had a few requests by users of the IPW2100 wireless driver to switch the 
> default interface name to be wlanX vs. ethX.  In my prior searches through the 
> wireless drivers in the 2.6.3 kernel tree, I couldn't find any that changed from 
> the default.
> 
> I don't mind adding a module parameter to change the default name (if that is 
> the standard practice), but thought I'd see what others thing rather than just 
> going off and doing something random.
> 
> Is there a technical or ease of use reason switching away from ethX?  My 
> thinking in keeping it eth was that it then represents a greater chance of "just 
> working" with most networking scripts and utilities that may assume ethX is the 
> interface name.

TBH I don't think it much matters. I know that at least Red Hat's networking scripts 
(and possibly other distributions) did at one point assume that each interface would 
be named ethX, but I don't think that is the case anymore.

Some drivers even present both a wlanX and an ethX interface, which I think is an atavism
that goes back to networking scripts breaking horribly on non-ethX interface names.

Going forward it might be worth while to standardize all wireless interface names, just
to show at a glance that an interface is 802.11x, and also to differentiate the fact that
eventually 802.11 will be its own network stack.

-- 
Matthew Galgoci
System Administrator
Red Hat, Inc
919.754.3700 x44155

Re: Device naming for wireless NICs...

[Jean Tourrilhes]

James Ketrenos wrote :
> 
> If this topic been hashed a lot already, please let me know the
> keywords I might search for in the archives to find the threads.
> 
> I've had a few requests by users of the IPW2100 wireless driver to
> switch the default interface name to be wlanX vs. ethX.  In my prior
> searches through the wireless drivers in the 2.6.3 kernel tree, I
> couldn't find any that changed from the default.

	This is my personal rule of thumb :
	o if the interface use Ethernet frames (i.e. offer Ethernet
emulation), then it should be name 'ethX'.
	o if the interface use 802.11 frames (rawe/native), it should
use 'wifiX'.

	The Aironet driver is a good example of this, for each
hardware it offers two interfaces, 'ethX' and 'wifiY'.
	Personally, I've been converting a few drivers to use 'ethX'
and removing 'wlanX' hacks where I saw them..

> I don't mind adding a module parameter to change the default name
> (if that is the standard practice), but thought I'd see what others
> thing rather than just going off and doing something random.

	Just point them to :
http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux/HOTPLUG.txt

> Is there a technical or ease of use reason switching away from ethX?
> My thinking in keeping it eth was that it then represents a greater
> chance of "just working" with most networking scripts and utilities
> that may assume ethX is the interface name.

	Note that the RedHat graphical configuration tool (neat) seems
to insist on only using 'ethX' names. Yes, only using 'ethX' is
generally safer (principle of least surprise).

	Have fun...

	Jean

Re: Device naming for wireless NICs...

[Jeff Garzik]

James Ketrenos wrote:
> 
> If this topic been hashed a lot already, please let me know the keywords 
> I might search for in the archives to find the threads.
> 
> I've had a few requests by users of the IPW2100 wireless driver to 
> switch the default interface name to be wlanX vs. ethX.  In my prior 
> searches through the wireless drivers in the 2.6.3 kernel tree, I 
> couldn't find any that changed from the default.

I lean towards wlan%d, but until we have the generic 802.11 stack going 
it's really up to the driver maintainer (you, in this case).

Like Matthew said, any code that assumes a specific interface prefix, be 
it eth%d or wlan%d, is buggy.  Users are allowed to choose random 
interface names for their interfaces, often via nameif(8) program.  My 
own ethtool program is broken in this regard...

	Jeff

Re: Device naming for wireless NICs...

[Jeff Garzik]

Matthew Galgoci wrote:
> Going forward it might be worth while to standardize all wireless interface names, just
> to show at a glance that an interface is 802.11x, and also to differentiate the fact that
> eventually 802.11 will be its own network stack.

I definitely want to standardize on something like wlan%d.  We should 
get that for free when a generic 802.11 stack is in place, which implies 
that there will be a common wireless helper as a peer to ether_setup() 
in the current tree.

	Jeff

Re: Device naming for wireless NICs...

[Matthew Galgoci]

> 	Note that the RedHat graphical configuration tool (neat) seems
> to insist on only using 'ethX' names. Yes, only using 'ethX' is
> generally safer (principle of least surprise).

neat is old and outdated :)

Have a look at the redhat-config-network tools in Red Hat Linux or in Fedora,
the system-config-network tools.

I am sure the author of the tools would appreciate feedback :)
 
-- 
Matthew Galgoci
System Administrator
Red Hat, Inc
919.754.3700 x44155

Re: Device naming for wireless NICs...

[Jean Tourrilhes]

On Thu, Mar 11, 2004 at 02:33:58PM -0500, Matthew Galgoci wrote:
> > 	Note that the RedHat graphical configuration tool (neat) seems
> > to insist on only using 'ethX' names. Yes, only using 'ethX' is
> > generally safer (principle of least surprise).
> 
> neat is old and outdated :)
> 
> Have a look at the redhat-config-network tools in Red Hat Linux or in Fedora,
> the system-config-network tools.

	I don't use Red-Hat, it's just that people here complain to me
when their Red-Hat doesn't work. The joy of being the "Linux expert".

> I am sure the author of the tools would appreciate feedback :)

	My approach has always been 'edit the darn text file', so I
may not be the most qualified on the subject of graphical tools. I
kept using the original Pcmcia scripts up to one month ago.
	Anyway, I write enough documentation on what I believe is "the
right way", but it's funny, the Red-Hat people never send me feedback
on those docs.
	But, somehow, life goes on and everything works ;-)

> Matthew Galgoci

	Jean

Re: Device naming for wireless NICs...

[P]

Jeff Garzik wrote:
> James Ketrenos wrote:
> 
> Like Matthew said, any code that assumes a specific interface prefix, be 
> it eth%d or wlan%d, is buggy.  Users are allowed to choose random 
> interface names for their interfaces, often via nameif(8) program.  My 
> own ethtool program is broken in this regard...

My trivial patch fixes that.
http://sourceforge.net/tracker/index.php?func=detail&aid=780937&group_id=3242&atid=303242

Just wondering about the release schedule for ethtool?

Pádraig.