We're in the process of migrating over to an ASA 5520 from a Pix 515. We've made several attempts and so far none have been successful.
I've used the pix to asa migration too and combed thoroughly through the resultant config and everything looks good, however the cutover never works. We're using the exact same IP's and simply moving the inside and outside cables to the new inside and outside ports on the ASA - and then restarting our router.
From the ASA I cannot ping to the internet if I specify to use the inside interface. I can ping both inside and outside addresses normally however.
Any help on where to start looking for an answer would be appreciated. I'm not sure how to debug the traffic going across the ASA.