Re: Debian box listening on UDP port 68

[Greg Norris <haphazard@kc.rr.com>]

I suppose you could "kill -9" the dhclient process, once the interface 
has been configured.  You run the risk, however, of the DHCP server 
reassigning your IP address to someone else, with no way for your 
system to react.  I wouldn't even consider doing this unless you also 
control the DHCP server, and can ensure an appropriately long lease 
time... even then, it's almost certainly a (very) bad idea.

In short, what you're seeing is perfectly normal behaviour for a box 
which obtains it's IP address via DHCP.  I strongly recommend that you 
leave it alone.