Netopia 4000 Series, Руководство пользователя программного обеспечения

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Multiple Network Address Translation 3-35
To make these changes, first limit the range of remapped addresses on the Static Map and then edit the
default ser ver list called Easy-Ser vers.
■ First, navigate to the Show/Change Map List screen, select Easy-PAT List and then Show/Change Maps .
Choose the Static Map you created and change the First Private Address from 192.168.1.1 to
192.168.1.4. Now the router, Web, and Mail ser vers’ IP addresses are no longer included in the range of
static mappings and are therefore no longer accessible to the outside world. Users on the Internet will not
be able to Telnet, Web, SNMP, or ping to them. It is best also to navigate to the public range screen and
change the
Static Range to go from 206.1.1.5.
■ Next, navigate to Show/Change Server List and select Easy-Servers and then Add Server . You should
expor t both the Web (www-http) and Mail (smtp) por ts to one of the now free public addresses. Select
Service... and from the resulting pop-up menu select www-http . In the resulting screen enter your Web
ser ver's address, 192.168.1.2, and the public address, for example, 206.1.1.2, and then select ADD NAT
SERVER . Now return to Add Server , choose the smtp por t and enter 192.168.1.3, your Mail ser ver's IP
address for the Server Private IP Address . You can decide if you want to present both your Web and Mail
ser vices as being on the same public address, 206.1.1.2, or if you prefer to have your Mail ser ver appear
to be at a different IP address, 206.1.1.3. For the sake of this example, alias both ser vices to 206.1.1.2.
Now, as before, the PAT configuration will allow any user on the Netopia Router's LAN with an IP address in the
range of 192.168.1.6 through 192.168.1.254 to initiate traffic flow to the Internet. Someone at the FTP ser ver
can access the Internet and the Internet can access all ser vices of the FTP machine as if it were at 206.1.1.5.
The router cannot directly communicate with the outside world. The only communication between the Web
ser ver and the Internet is through por t 80, the Web por t, as if the ser ver were located on a machine at IP
address 206.1.1.2. Similarly, the only communication with the Mail ser ver is through por t 25, the SMTP por t,
as if it were located at IP address 206.1.1.2