On Tuesday 28 April 2009 07:51, Nifty Fedora Mitch wrote: > On Sun, Apr 26, 2009 at 05:51:52PM +0200, Marko Vojinovic wrote: > > In short, what is the difference? Are there any (dis)advantages of > > using one over the other? > > Put your subject line in a search engine like Google. > > http://www.dcs.gla.ac.uk/~lewis/networkpages/m05s09NAT.htm > > For most "mortals" NAT is just fine. > NAPT may be needed on a large private network but > the hardware/ software has to work harder and thus > may cost more. Well, I was already beginning to worry if my post made it to the list at all. :-) Of course, I did do some research on the subject, but all that I found was described in a very general way, and consequently vague. So I was hoping to start a conversation with someone knowledgeable, in order to get more concrete answers. My setup consists of three to five computers and a small wireless router, with an adsl uplink utilizing a dynamic public IP address (just a single one, the m=1 case in the article you quoted). What I would like to understand better is the following: * Why does my ISP's router manual insists on using NAPT over NAT? The ISP tech support admitted to not understand why and have no explanation, but nevertheless they suggested that I set up the router as the manual says. Is there a general well-known reason for insisting on such a setup? * Is there a performance penalty in using NAPT over NAT? Packets have to be altered and reassembled in both cases, so should I really expect any notable time difference here? * Given my setup from above, is there a serious need to use NAPT over NAT? If yes, why? If not, why not? (note: I consider muself just a simple mortal with a small home network, nothing too fancy) * I understood that NAT is about mangling the source IP address of the packet so one could push more local IP addresses through less public ones. I fail to understand the further gain of mangling tcp/udp port numbers? Can you provide an example situation where NAPT works and NAT doesn't, so I can visualize the difference in packet travel? * Is it probable that the NAT setups I have created in the past (typically on Linux machines playing as routers, using mostly firestarter built-in NAT support) were actually NAPT setups, while I wasn't explicitly aware of the difference? IOW, is it maybe usual to say/write NAT in software manuals while actually meaning NAPT instead? I tried to do my homework here, but these questions somehow just weren't quite answered in any NAT vs NAPT articles I could find on the net. I would appreciate any hints in understanding all this a bit better. Thanks, :-) Marko -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines
