Re: Specifying names for tap interfaces

[Darren Reed <darrenr%netbsd.org@localhost>]

On 24/06/2012 12:09 AM, Manuel Bouyer wrote:
> On Sat, Jun 23, 2012 at 11:51:51PM +1000, Darren Reed wrote:
>> Not really.
>>
>> If the type of network interface card changes then the
>> configuration that specifies the label needs to be updated.
> 
> Yes.
> 
>>
>> The goal here is to have the system probe cards and assign
>> them a name that is independent of the card/driver. This
>> then allows the card to be changed with no action required
>> by the owner of the system to update the configuration.
> 
> And how is the name assigned ? 

You can do it any number of ways.

In the first, you might do it in the kernel, with autoconf.

Another is that you have an application or daemon that is
run when the system boots and applies either a rule or set
of already decided upon naming assignments, such that by
the time the system gets to single user mode, the interfaces
have already picked up their new name.

Another might involve writing device naming state into a
file that is opened and parsed by the kernel at boot.

>> Linux's method associates names by driver type (eth0, eth1, etc).
> 
> Yes, and it's also associated with the hardware. On a system with a
> add-on PCI ethernet called eth0, if you replace it by another PCI ethernet
> (even if it's the same model, as the name is actually attached to the
> ethernet address) it'll be called eth1. You have to edit sysconfig files
> to have it named eth0 again.

That's an implementation issue.
Or possibly even a naming policy issue.

Solaris 11 doesn't suffer from that.

There's no reason why NetBSD would have to suffer like that.

Darren