Documento interessant�ssimo Hugo - de onde voc� tirou ?! (se n�o se importar
em responder)
-----Original Message-----
From: Hugo Caye [mailto:[EMAIL PROTECTED]]
Sent: sexta-feira, 12 de janeiro de 2001 00:18
To: Lista de Discuss�o Rede Wan
Subject: RE: [redewan] NAT x Proxy
Compras com facilidade e seguran�a?
ShoppingBOL
http://shopping.bol.com.br
Lista de Discuss�o Rede Wan - http://www.networkdesigners.com.br
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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