JoaoBR <jo...@matik.com.br> wrote:

Changing the behaviour of tools always involves a certain danegr of breaking existing script. That's especially true for symstem administration commands such as ifconfig that are running in automated scripts, and people depend on them for booting their machines remotely.

I'm not saying that people are intentionally using that syntax ... Maybe they are, maybe not. But you also should take into accounts that there might be scripts that use the syntax inadvertantly and happen to work correctly because of the current behaviour.

I'm also _not_ saying that the behaviour must not be changed at all. But it should be done carefully, i.e. first to -current, with proper "heads up" warnings. Don't change it in RELENG_6 without warning and expect evrybody to be happy.

It might be confusing to you. Personally I think that the current behaviour isn't that far off.

First you need to be aware that there is no distinction between a primary IP and alias IPs (such a distinction existed historically, but it's gone). All of the IPs on an interface are equal, just like hardlinks on a file. Maybe the manual page should be clearer about that.

The "-alias" parameter simply removes an address from an interface. The term "alias" should really be avoided because it is misleading. You can use "delete" or "remove" which do the same thing. I think "-alias" should really be regarded to exist for backwards compatibility only. Personally I always use "delete".

If no IP address is specified, then it's not completely nonsensical to remove the first address. In fact I've used that short-cut to quickly remove the only address from an interface. I've used "ifconfig xyz0 delete" quite a lot.

That's the same as "ifconfig nic add". If you don't tell it anything to add, then it won't add anything, of course. Remember that UNIX always tries to do exactly what you tell it to dao. ;-)

That error corresponds to EADDRNOTAVAIL, which is the correct errno to return, because there's no address left on the interface. However, I agree that the message is a bit confusing to the unfamiliar.

Best regards Oliver

I suggested holding a "Python Object Oriented Programming Seminar", but the acronym was unpopular. -- Joseph Strout