If the PIX had previously been upgraded from a PIX Version 6.3 version, the 4-tuple activation key is stored in Flash and does not need to be re-entered. Even if the PIX Version 7.0 code license had been subsequently updated using a 5-tuple activation key, the 4-tuple key is still saved. The downgrade command verifies and uses the 4-tuple key, if it exists. Otherwise, the activation key needs to be input in the CLI for the command to succeed.
