when my pix failed I switch over rapidly to a asa 5505
two of my external ip address say 1.1.1.x and 1.1.1.y are replying to ping replies from the internet. one address is used in my outside interface and the other is used in my route outside command
interface Vlan2
nameif outside
security-level 0
ip address 1.1.1.x 255.255.x.y
te outside 0.0.0.0 0.0.0.0 1.1.1.y 1