Eric,
The many answers to your questions are in RFC 2993 and in
http://www.ietf.org/internet-drafts/draft-ietf-nat-protocol-complications-06.txt
(which will soon be an RFC).
Brian
TOMSON ERIC wrote:
>
> <EXAMPLES>
>
> <EXAMPLE 1> I have a CATV connection at home. I get only 1 dynamic public IP
>address. However, I have a small internal network (some couple of computers). How can
>I guarantee a full Internet access to each one of these computers? => By installing
>W2K A.S. with NAT on a PC having 2 NICs (1 NIC connected to the CATV modem, 1 NIC
>connected to a switch), allowing a full transparent Internet access to an
>undetermined number of PC on my private LAN (depending on the range of private
>addresses I use). </EXAMPLE 1>
>
> <EXAMPLE 2> A company has a LAN composed of hundreds of computers and wants to give
>some limited access to the Internet, to its internal network. They subscribe to an
>ISP and ask for 10 fixed addresses. They install a router and configure it with NAT
>in such a way that any 10 internal hosts can have concurrent connections to the Net
>by dynamically getting a temporary map between their internal address and one of the
>10 public addresses. As soon as a PC disconnects, its mapped address can be assigned
>to someone else. </EXAMPLE 2>
>
> </EXAMPLES>
>
> <QUESTIONS>
> * What is the problem using NAT in any of these 2 examples?
> * Since routers only work on network addresses and not on host addresses, what is
>the problem - for any routing table - of using NAT in any of these 2 examples (in
>case 1, only the network ID of the unique official address has to be known by the Net
>; in case 2, most probably 1 unique network ID will be used by the 10 official
>addresses)?
> </QUESTIONS>
>
> <COMMENT>
> By the way, IPv6 brings much more answers than just a solution to the address space
>(which is not simply 4 times wider - which could be achieved but simply adding 2 bits
>to the 32 bits of IPv4 - but actually 2*2*2*...[128-32=96 times]...*2 times wider,
>i.e. 2^96 times wider) : [host, routing and network] autoconfiguration, quality of
>service, better and more efficient IP headers, security, performance, mobility,...
> </COMMENT>
>
> E.T.
