Date: Jan 12 2001 06:24:56 EST
From: Hugo Caye <[EMAIL PROTECTED]>
Subject: Re: [redewan] NAT x Proxy


Sugest�o? Use os dois (Win2K Srvr e sob ele o MSP), mais seguro, mais
recursos, mais desempenho, melhor e mais capacidade de gerenciamento.

Apertado de grana? Use apenas o NAT do Win2K.


"--------------------------------
What's the Difference Between 
a NAT Server and a Proxy Server?
--------------------------------
That's a good question. A Proxy Server is a device that 
can forward and receive packets on the behalf of another 
computer. So, when a computer on your internal network makes 
a request for resources on the Internet, the Proxy Server 
will intercept this request and forward it to the Internet 
server on your internal computer's behalf. When the Proxy 
Server receives the response from the Internet server, it 
forwards the response back to the internal computer who 
initiated the conversation.

How is this different from a NAT Server? This is a 
conversation and argument I've had many times with students 
and colleagues. They tell me that a Proxy Server is not a 
NAT Server, and that they do very different things. When I 
ask them how they are different, I get a blank face and the 
answer that "someone told me that was so". Don't try 
supporting your arguments this way in a job interview!

A NAT Server translates packets so that machines on a 
private network, using private network addressing, can 
access resources on the Internet. The source IP address 
on the internal client's request is replaced with the IP 
address of the external interface of the NAT Server. The 
Internet server responds to the request from the NAT 
Server's external interface and the NAT Server forwards 
the response to the internal client.

A Proxy Server does that same thing, but is able to access 
application layer information and make decisions on what to 
do with a packet based on that information as well as 
information provided by the lower level protocols. Although 
NAT Servers can have "NAT Editors" installed on them, they 
are relatively rudimentary and do not have the same 
capabilities of a Proxy Server's suite of application 
filters.

More important than the minor differences on how address and 
application filters work between a NAT Server and a Proxy 
Server, is that a Proxy Server is able to make decisions on 
whether or not to allow a packet to pass based on rules you 
have configured on the Proxy Server. The Proxy Server 
compares the information contained in the packets with the 
rules set up on the server and then makes a determination 
on whether the packet will be passed or dropped."

-----Original Message-----
From: Andr� Roberto Steffens
[mailto:[EMAIL PROTECTED]]
Sent: ter�a-feira, 9 de janeiro de 2001 11:44
To: Lista de Discuss�o Rede Wan
Subject: [redewan] NAT x Proxy
Importance: High


Lista de Discuss�o Rede Wan - http://www.networkdesigners.com.br


	Pessoal,

	Estou pensando em usar o NAT do Windows 2000 Server ou o MS
Proxy Server
2.0 em uma rede com umas 30 esta��es (no m�ximo).
	Acesso discado (Multilink - 128kbps com a AT&T).
	O que voc�s sugerem ?! Algu�m tem algo contra um dos dois ?!
	Sei que um � um pouco mais r�pido pois s� traduz os endere�os,
mas o outro
tem cache. E quanto a seguran�a ?! Posso implementar algo com o NAT,
preciso
de um Firewall ?!


	Andr� Roberto Steffens
	Microservice Tecnonlogia Digital
	(11) 3959 1281


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