I did a bunch of 6.3(5) to 7.2(x) upgrades, but I did them differently than how you want to. I backed up my 6.3 config then installed a fresh image of 7.2 code. After that, I copied/pasted the old config section by section into the newly upgraded PIX. This might take a little longer (how long depends on the complexity of your current config), but in the end, you have a cleaner migration.
There are some instances where you can't simply copy/paste, so you will have to enter some commands such as the following:
conduits should be converted to ACL's
no more fixup commands
and vpn tunnel groups.
I believe if you copy/paste in existing vpn configs, the 7.2 code will automagically convert them to the new syntax for you...i think.
activation keys handle the upgrade just fine. as a precaution, copy down the key just in case. I once did a downgrade (albeit incorrectly) from 7.x to 6.x and it completely wiped out the activation key - which of course i hadn't thought of backing up.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...