I'm not quite sure what "Secure IOS" is, Google and Cisco.com don't yeild any promising results on that. However, there's no shortage of mention of "Cisco Secure IOS Firewalls", so perhaps it's a marketing wank-word?
Whether Cisco IOS itself is secure or not is a topic of discussion for another forum >:}.
However, to answer your question, when you talk about the IOS-varient that runs on the PIX, you're essentially describing an IP Forwarding engine with a different default set of security policies with a default "deny/block any/any" as defined by the "ASA" system (not to be confusecd with the ASA hardware line).
You're also talking about strong cryptography/ authentication/security features that may be optional addons on traditional IOS.
I was at a "Lunch&Learn" hosted by Cisco on Friday and the Cisco sales rep (Chris Oggerino) ? essentially portraited the ISR router as ideal for complementing entry-level switching gear in "Branch" offices where concepts like "Perimeter" router, "Inside Firewall" might not apply, and features like IDS, IPS, Redundancy, Voice might traditionall be independant hardware units, are features on the ISR. Of course, you still need two of everything for HSRP/BGP >:}
It's a question of budget and design. Do you want your firewall to be an autonomous device.
TIA,
~lava
~lava
