Comment by tptacek

15 hours ago

There's no uncertainty at all about what NAT was meant to do; you can just read Cisco's introduction to the PIX, or it's statement about the acquisition of NTI, which are online.

Network administrators (less so security engineers) don't want NAT to be a security feature, so they've retconned a principle of security engineering that doesn't exist. If people were honest about it and just said they'd prefer to work on networks where less distortive middlebox features provide the same security controls, I'd have nothing to argue about.

But this article makes the claim that "NAT isn’t actually a security feature". That's simply false. People need to stop rebroadcasting this canard.

14 comments

tptacek

zamadatix 15 hours ago

One could see the inlined, sourced, and dated references I placed above about the PIX rather than searching online from scratch or making assumptions of others reasons or intentions.

What some people do or don't want in the 2020s has no relevance to the reasoning in the 1990s, nor does it redefine the purpose or use of NAT the same. The above is clearly and directly stated from the sourced material of the era itself: NAT was introduced in the mid 90s due to concerns about address space depletion and the need to move to IPv6. The security features of said introductory appliance never came from or were supposed to come from implementing NAT, but from implementing stateful firewalling and blocking inbound connections. There is no personal opinion or retconning in any of this, they aren't even the postings of anyone from this century.

tptacek 14 hours ago

Your own sources confirm what I'm saying.

simoncion 13 hours ago

> Your own sources confirm what I'm saying.

I don't see where they do. I see them talking almost exclusively about working around address depletion.

Hell, look at Cisco's press release for its acquisition of Network Translation, Inc. [0] It's all about address depletion and resource efficiency; security is mentioned as an afterthought. I'll quote the relevant paragraphs (and leave in the line break mangling present in the original).

  SAN JOSE, Calif., October 27, 1995 - Cisco Systems Inc. today announced anagreement to purchase privately-held Network Translation, Inc. (NTI), anetworking manufacturer of cost-effective, low maintenance network addresstranslation (NAT) and Internet firewall equipment. The investment isintended to broaden Cisco's offerings for security conscious networkadministrators who want to dynamically map between reusable private networkaddresses and globally unique, registered Internet addresses. Through itsacquisition, Cisco will gain NTI's Private Internet Exchange (PIX) solutionwhich helps network administrators resolve their growing need forregistered IP address space. NTI's 10 employees and products will beincorporated into Cisco's Business Development efforts reporting to VicePresident Ed Kozel. The financial terms of the purchase are not beingdisclosed. The transaction is expected to close by the end of November andis not subject to the Hart-Scott-Rodino filing.
  
  The NTI investment is the second action by Cisco in recent months tostrengthen its expertise in resource-effective Internet access technology.NTI technology will interoperate with and integrate several functions ofthe Cisco Internetwork OperatingSystem(tm) (Cisco IOS) software,facilitating use throughout the enterprise. NTI addresses two of the morecompelling problems facing the IP Internet -- IP address depletion andInternet security. Customers using the NATalgorithm can take advantage ofa larger than assigned pool of addresses. NAT makes it possible to useeither your existing IP addresses or the addresses set aside in InternetAssigned Number Authority's (IANA) reserve pool (RFC 1597). Cisco's goal ofintegrating NTI's technology and personnel is to ease the complexity ofInternet access for applications including telecommuting and World Wide Webaccess.

[0] <https://newsroom.cisco.com/c/r/newsroom/en/us/a/y1995/m10/ci...>

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