On 02/14/2011 11:17 AM, Florin Iucha wrote: > On Mon, Feb 14, 2011 at 10:45:39AM -0600, Justin Krejci wrote: >> Explain how NAT does this? NAT simply mangles the IP headers. >> A stateful firewall can protect you from port scans and other baddies >> without NAT. > > If an attacker can't know your IP address, they can't connect to it. Is that a motive to postpone IPv6 deployment? If so, see RFC 3041 (Privacy Extensions). However, using security-by-obscurity as an argument on this list is almost as pointless as Godwinning the thread... ;-) >> It is bad because it has broken protocols, applications, and end-to-end >> communications and caused much grief and likely loss of functionality in >> various applications because of it, unseen loss of functionality. > > Facebook? Google? Flickr? Netflix? Actually, yes, possibly. LSN/CGN (large-scale/carrier-grade NAT) has the potential to wreak havoc on AJAX-happy implementations, simply due to port exhaustion (as you later mentioned). IIRC Google (particularly Maps) and Facebook are pretty AJAX-heavy; I imagine the others might be. >> I maintain NAT is evil. And even "extending the life of IPv4" is >> debatable as a plus for the overall picture. > > I do not maintain that NAT is beautiful for everybody all the time. > But 'evil' is a loaded term that should be reserved for special occasions. I can agree with your position on the word "evil." The word is tossed around far too casually -- I'm guilty of that, too. The pro/anti NAT discussion has been played out many times before, probably most frequently on the NANOG list. Jima