<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.
