In message <200511081722.jA8HMq7h002129@lothlorien.nfbcal.org>, Brian Buhrow wr
ites:
>	I believe the dhcp spec says you must renew after half of your lease
>time has expired.  So, if your lease is 7 minutes, your client will have to
>renew after 3.5 minutes.  This is a fairly short time frame, it's possible
>not all the network glue that dhclient pastes into your configuration gets
>completely settled between renew cycles.  Typical lease times are between
>15 minutes and 24 hours.  For really stable environments, lease times of a
>week are quite common.  A week is what I use on my home systems, and that
>just works for everything I've ever connected, laptops running Windows,
>WIFI IP phones, Tivo boxes, other strange stuff.
>So, try upping the lease time, and see if that changes the behavior you
>get.  I'm not sure why Steven's suggestion works, but it does hint at a bug
>somewhere, either in dhclient, or our routing code.

The problem occurs when the address changes; if it stays the same, you 
don't see any trouble. 

As for lease time -- it can be (and generally is) capped by the server, 
too.

		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb