This may be obvious to many of you, but for me it was a half a day of futzing followed by a dope slap. Perhaps this will save time for someone else. I will post it to my web pages soon.
I bought one of the Linksys BEFW11S4's from the sale at Bestbuy, to make sure they worked as well as I remembered and to experiment a bit. I set IP addresses and names and WEP and, as Nigel's least favorite relatives might say, "Bob's your uncle..."
I have a pre-existing internal network, with DHCP on the firewall recognizing the MAC numbers of my laptop ethernet interfaces. It assigns fixed IP numbers to them. This helps with automated backups, ssh logins, etc.
A BEFW11S4 out-of-the-box setup performs its own NAT, and its own DHCP, so the laptops are undiscoverable when connected through the Wifi or the 4 router ports of the BEFW11S4. Bummer.
I tried a number of things that did not work. What worked was to treat the "Internet" port of the BEFW11S4 as irrelevant, turn off the NAT and DHCP, assign the BEFW11S4 setup a fixed IP address within my inside address space ( 192.168.100.### rather than 192.168.1.1 ), then connect one of the 4 router ports with a **crossover cable** to my inside ethernet router. I then entered the MAC address of my senao card into the DHCP tables, as an alternative entry for the laptop name.
Now, if I connect my laptop with ethernet to one of the three remaining ethernet ports on the BEFW11S4, and turn on eth0, it DHCP requests to the inside network and finds the correct address for the laptop. The same thing happens when I turn off the ethernet and turn on the wireless. I guess the only thing left is to make my incoming modem ppp find the same address for the laptop, and make a VPN work that way for road trips.
One mystery remains: Though I have turned off NAT, Kismet reports an IP range of 192.168.1.100, the default dhcp for the untwiddled BEFW11S4. No big deal for me, but those believing in truth-in-advertising might want their WAP reporting the real DHCP address range.
last revision May 7, 2004