Iptables not blocking DHCP/UDP correctly?

["Larry Kelly" <Larry.Kelly@noaa.gov>]

Help!  Either iptables is not blocking DHCP requests or my understanding of
how to configure iptables to block is incorrect (probably the later).  

   Sys w/dual NIC cards
   Running Debian 3r2  
   dhcpd installed and running (listening on all interfaces).

   iptables configured to block incoming and outgoing udp traffic.

   A client on one of the interfaces makes a dhcp request.
   Gets an acknowledgement w/IP address from the server.

   From what I understand about iptables, shouldn't these packets get
dropped?  How is DHCP server seeing and responding?  Iptables config and
daemon log output follows.

   Thanks!
  
     -Larry
   
   Output from iptables -L:

Chain INPUT (policy ACCEPT)
target     prot opt source               destination
DROP       udp  --  anywhere             anywhere

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination
DROP       udp  --  anywhere             anywhere

   daemon.log output:

Oct 28 13:34:20 dhcpd-2.2.x: DHCPREQUEST for 10.0.0.10 via eth1
Oct 28 13:34:20 dhcpd-2.2.x: DHCPACK on 10.0.0.10 

~~~~~~~~~~~~~~~~~~~~~~~~~~
Larry Kelly