I21st, Thanks for the reply. The perimeter router is DSL. Does the pix require the PPPoE client to be enabled? If you have DHCP enabled on the outside interface, the Pix will automatically disable the PPPoE client you require - and vice versa if you have the PPPoE client enabled.
I still have not found the right config to connect a 501 behind a Linksys DHL router. The following does not work.
PIX(config )# interface ethernet0 10baset
interface ethernet1 10full
ip address outside dhcp setroute
global (outside) 1 interface
nat (inside) 1 0.0.0.0 0.0.0.0
ip address inside 10.10.1.1 255.255.255.0
Config on PC
Ip address 10.10.1.2/24
default gateway 10.10.1.1