Problems with OpenBSD dhclient

[Eric Anderson]

Brooks Davis wrote:
> On Thu, Jul 14, 2005 at 12:08:45PM -0700, Frank Mayhar wrote:
> 
>>On Thu, 2005-07-14 at 11:58 -0700, Brooks Davis wrote:
>>
>>>I'm seeing this as well.  I think we're going to need to handle wireless
>>>and wired interfaces differently since their links work differently.
>>
>>I tend to disagree with this view.  In general, while wired connections
>>may often be more persistent than wireless connections, that's not
>>necessarily always true.  It's certainly possible to move a system
>>between wired connections as well
>>
>>I think that it makes more sense for the configuration of the two types
>>to be the same, anyway, just for consistency.  It's the same basic
>>problem that is being solved, and if the solution for wireless
>>interfaces is reasonably robust, it should work just fine for wired ones
>>as well.
> 
> 
> The problem with attemping to keep them looking the same is that
> wireless interfaces have more complex state.  We're currently trying to
> paper over that, but it isn't really working.  With wired interfaces, you
> either have a cable with something on it plugged in or you don't (at
> least until we get 802.1x support).  With wireless interfaces, you can
> change association relativly seamlessly so mapping associate/deassociate
> to linkup/linkdown as we do now is bogus.  In the end, from the user
> perspective, there should be no visiable difference between wired and
> wireless interfaces unless you try mucking with the devd config or need
> to use WPA.

Here's what I think would work well in most situations:

if an interface (A) changes from down->up, and was not previously 
configured with dhclient, dhclient should run on it (if set in rc.conf). 
  If another interface (B) is currently down, that has dhclient running 
on it, then when interface (A) comes up with a valid ip, it should 
remove the ip info from interface (B).

if an interface (A) changes from up->down, and dhclient is running on 
it, it should not do anything.

if an interface (A) changes from down->up, and dhclient is running on 
it, and no other interfaces are up, it should try to get it's lease, 
without changing it's current IP setup until it has the new information.

If an interface (A) changes from down->up has conflicting IP information 
with an interface (B) that is down, that dhclient manages, it should 
remove the IP setup from interface (B), and set routes according to the 
newly upped interface.

If an interface (A) changes from down->up, and there is another 
interface (B) that is up that dhclient manages, then configure interface 
(A) only if it will not conflict with the other interface's (B) network. 
  This could be an rc.conf option - to force newly brought up interfaces 
to override currently up interfaces.

Anything I missed?

Eric




-- 
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Eric Anderson        Sr. Systems Administrator        Centaur Technology
A lost ounce of gold may be found, a lost moment of time never.
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