what is the story on if_index allocation ?

[Harti Brandt]

On Wed, 21 Apr 2004, Petri Helenius wrote:

> Luigi Rizzo wrote:
>
> >Can someone explain what is the goal ? Reuse a number if an
> >interface has the same name of a previously existing one and
> >the index is free ? And does it make sense, anyways, or
> >we could just simplify that code and just reuse the first
> >available entry in ifindex_table[] ?
> >
> >
> The optimal course of action (from management software point of view) is
> to retain as static ifName to ifIndex mapping. If the index changes for
> the same interface, you're supposed to have lower sysUpTime than on
> previous query.

That mapping certainly has problems with interface renaming. Currently
there is no way of getting at the driver's name of the interface.

harti