Interface start-up ordering sequence, multiple passes?

[Pekka Savola]

On Tue, 16 Sep 2003, Paul Jakma wrote:
> > Have I missed something, or is this impossible at the moment
> > (without gluing more stuff in init.d/network)?  Would such
> > mechanisms be useful in other contexts as well?
> 
> yes, definitely.
> 
> either a file to specify interface order, or else something like a 
> generic DEPENDSON parameter to specify dependencies. File to define 
> interface order is probably by far easiest to implement,

This is a good idea, but with more consideration, it may not be entirely 
trivial in the case that DEPENDSON would have to list more than one 
interface, or something generic like, "the interface the default route 
points to".

The more I think of this, the more interesting this 
DEPENDSON="<one-interface>"|"default" sounds; the latter would be a 
general term to look up a default route (or something like that).
 
> > (This could be achieved, it seems, at least by using an '/sbin/ifup
> > xxx 2ndpass' argument, and only specified commands would be run
> > when doing the second pass.)
> > 
> > Thoughts, ideas, comments?
> 
> i'd go with a file a la:
> 
> cipcb9
> cipcb?
> eth2
> eth1
> eth?
> 
> and have the network scripts look for init scripts in the specified 
> order in that file.

The ordering may not always be so trivial, like "VPN interfaces" and 
"regular interfaces".  Eth0 could be upstream while eth1 would be intranet 
interface (and one could require the other), for example.

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings