Our ADSL service goes to a Linux box running Shorewall firewall and
contains a public server (web, IMAP, SMTP, VPN etc). We have static
IP's from our ADSL provider, but still require DHCP to obtain them.
We cannot hard-code them.
Anyway,there is a second ethernet card in the Linux box
(192.168.121.x) that is connected to a switch that goes to our
internal network. There are other servers and a few local machines
conected to the switch. We also have a BEFW11S4 connected to the
switch via one of the BEFWssS4's LAN ports.
We previously had the BEFW11S4 setup as a bridge and using WPA-PSK.
All of our laptops had static IP's. No problems. We don't want this to
be the case anymore as we use our laptops in other locations that use
DHCP. We decided to switch the BEFW11S4 to use DHCP for all the
wireless clients.
We left the "Internet Connection Type" as "Heart Beat Signal" as we
don't have anything connected to the WAN port. This worked for us
previously. We have given the router an IP of 192.168.121.30, enabled
DHCP, and set the start address to 192.168.121.100 with 5 addresses
available for clients. The lease time is set to 0 (max lease time) and
the DNS servers are set to our internal nameserver. We have also
restricted access to specific MAC addresses as well. Our routing table
has one entry:
Dest: 192.168.121.0 Subnet: 255.255.255.0 GW: 0.0.0.0 Hops: 1
Inteface: LAN
When a client connects (eg a laptop with an Intel Pro/Wireless
2200BG), it connects to the wireless router (so our WPA-PSK it set up
correctly), but it obtains an IP address from our ADSL provider. Even
if we disconnect all the cables to the wireless router, it does not
give out IP addresses at all.
The laptops work perfectly with other wireless systems obtaining an IP
as it should. For some reason, our will not. We have tried rebooting,
reset to defaults, updating the firmware, but nothing! I know we have
used DHCP on this unit before.
DHCP, BEFW11S4, internal network 
Linear Mode
