I have an ethernet microcontroller which I am trying to ping from my wireless (WLAN) side of my Linksys WRT54G to the wired side of it (LAN). I can ping the microcontroller when it is attached as a device to another router on my network, but I cannot, for the life of me, ping it when it is connected to my Linksys. Is there some kind of natural firewall between the wired and wireless side of this router? There shouldn't be since they are on the same subnet that is defined by the DHCP server in the Linksys. One other thing, I said that I was trying to ping my device... it has a static IP address (that I can set internally). I made sure that the static IP address was set to a number lower than the range used by the DHCP. Funny thing is it works, when I have it connected to another router that is hooked up higher in my network (the second router is at 192.168.15.1 while the problem router is at 192.168.1.1). In this instance, I have the device setup as 192.168.15.10 and it works fine pinging from the 192.168.1.1 side of the network. What doesn't work, is when I change the device to 192.168.1.10 (on the LAN) even though my computer is at 192.168.1.100 (on the WLAN). It should work but doesn't!