Re: Problems with OpenBSD dhclient

On Thu, 14 Jul 2005, 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.

I reported a similar problem a year or so ago shortly after changes were 
committed to the old dhclient so that it dropped the IP address on an 
interface when the link went down.  The problematic behavior had to do 
with a loose ethernet cable, which would have to be re-inserted.  If the 
IP is left on the interface, connections will hang and recover.  If the IP 
is removed, then applications will get socket errors due to using an IP 
address that is no longer available, closing TCP connections.  One failure 
mode is clearly more desirable than the other in the environment I was 
using the system in (sitting on a couch).

Robert N M Watson