I have a little (headless) ARM box running Debian with a built in clock module, but whose battery had died. On replacement the box failed to get an IP address via DHCP.
On investigation it appears that because the clock was "wrong" it couldn't perform DHCP queries ("Unable to setup timer"). I think "wrong" doesn't just mean inaccurate (it was claiming to be in 1928) but corrupt (hwclock reported corrupt registers).
The clock would get reset by a time server as soon as it got online, but without valid clock it couldn't get online to get the valid clock...
Anyone know any more about this or able to point to a general workaround for next time this happens?
All I have found (after the event) is here: http://www.solid-run.com/community/viewtopic.php?f=8&t=525 .. which confirms what I thought but doesn't really offer a solution (logging in to set the clock on a remote headless unit isn't particularly convenient!)
Mark