The "security" you attribute to NAT does not come from NAT, it comes from using "private" addresses.
Im pretty sure thats what I said, and no one is arguing that point. You're just insisting on being pedantic and condescending.
Your original statement was that NAT is not security. This post of yours agrees that it is security in some shape. If we're agreeing there, then I dont think theres any reason to keep arguing. If youre disagreeing with that, Id ask you to take it up with the links I provided and with stackexchange. I dont have the time to try to make Cisco and SANS' cases on their behalf, if you are unwilling to take their word on it.\
. Besides, why do you trust your ISP not to snoop around on your network?
Because it is an unusual attack scenario, and it would be illegal. It does happen, sure, and defending against a malicious ISP is far beyond the scope of most home security. Luckily for us every consumer OS made in the last 10 years has a stateful firewall, and every consumer router built in the last 10 years has a firewall, so its not an issue.
I mean good grief, 99% of home users are using the ISP provided DNS, and you're worried about probing through NAT in violation of the RFCs? DNS snooping is something that actually happens, and is actually legal. Risk assessment 101: focus on the probable threats.
Without mentioning the need to filter incoming packets, that tutorial concludes: "A computer located in the internet is not able to establish a connection to a local computer, all he can do is address (a port of) the router and hope the best."
Wrong, and leaves anyone who follows the tutorial vulnerable.
As mentioned already, it is impossible in the absence of a published route to your network for someone to reliably send packets directly into a dynamically natted network. The fact that someone could splice onto your cable network is irrelevant, because at that level of effort they could probably climb in through your window and just steal all of your equipment. You're talking about extremely esoteric attacks.
You're really doing people a disservice by perpetuating the myth that NAT adds security.
Im perpetuating the stance of major infrastructure vendors. Argue with them. I imagine you could contact support@cisco.com and explain why their statement that NAT fulfills a security role is incorrect.
In the meantime I would suggest you cut the condescending attitude.