Re: Getting NM to re-try DHCP

[Dan Williams <dcbw redhat com>]

On Tue, 2011-04-05 at 11:37 -0400, Derek Atkins wrote:
> Hey all,
> 
> I have a strange issue.  I lost power last night and one of my systems
> came up before my DHCP server did (which is surprising, because my DHCP
> server usually comes up pretty quick!)  This "client" system was
> supposed to get itself on the network (it has an auto-logon system).
> However, NM didn't succeed because my DHCP server wasn't responding,
> yet.
> 
> This is a hard-wired system (not wireless).  Is there any way to get NM
> to periodically retry DHCP if at first it does not succeed?
> 
> I realize that DHCP has its own retry mechanism, but if the whole
> process times out, can I set NM to retry every, say, 5 minutes?

We'd need some code changes in NM; basically for wired connections if
the activation attempt fails a certain number of times (currently 3)
then the connection is marked "invalid".  What probably should happen is
that internally, in nm-policy.c, a timeout handler should be scheduled
for the connection (using g_timeout_add_seconds()) that triggers after 5
minutes or so and if the connection isn't currently active (ie check the
NMManager's active connection list) then the invalid flag is cleared
from the connection, which will let it be automatically retried.

It's pretty simple from a code perspective, just hasn't been done yet in
the run-up to 0.9 and 0.8.4.  Any takers?

Dan