DHCP without network access

[maze at cela.pl (Maciej Żenczykowski)]

Hi,

I've got a box with CentOS 4.2 x86_64 which had no DHCP access for a few 
hours, now I can't ping it (I'm pretty sure the box is still up).  I 
expect the DHCP lease has timed out and the box has lost it's IP, I was 
expecting it to reacquire it once the DHCP came back up (configuration 
problem) - but no luck.  Is this a known problem? Any solution/workaround?
(for now or for the future...)

Cheers,
MaZe.