ZyXEL Communications Prestige 623 series User Manual page 89

Step 3. In the Local Address From and Local Address To fields, type the starting and ending IP
addresses that identify the range of private addresses you want to be translated. Or, type the
same address in both fields.
If you specify a range, each address will be translated in sequence to a corresponding address in
a range of global addresses (which you specify in step 4).
The address (or range of addresses) should correspond to a private addresses (or addresses)
already in use on your network. These may be assigned statically to your computers or assigned
dynamically using DHCP, as discussed in the previous chapter.
Step 4. In the Global Address From and Global Address To fields, type the starting and ending
addresses that identify the range of public IP addresses to translate your private addresses to. Or,
type the same address in both fields (if you also specified a single address in step 3).
Step 5. Specify a destination address or addresses, destination port (or ports), or both. You can specify a
single value by entering that value in both fields.
•
Specify a destination address (or range) if you want this rule to apply only to outbound
traffic to the address (or range).
If you enter only the network ID portion of the destination address, then the rule will apply
to outbound traffic to all computers on the network.
•
Specify a destination port (or range) if you want this rule to apply to any outbound traffic to
the types of servers identified by that port number.
For example, if you do not specify a destination address, but specify a destination port
from/to of 21, then this translation will occur on all accesses by your LAN to all external
FTP servers (that is, when one of your LAN computers communicates with an external FTP
server, the source IP address in the packet headers is changed to the public address, not the
initiator's private IP address).
Common port numbers include:
20, 21—FTP (file transfer protocol) server
25—SMTP (simple mail transfer protocol) server
80—HTTP (World Wide Web) server
•
Specify both a destination address (or range) and a destination port (or range) if you want
this translation rule to apply to accesses to the specified server type at the specified
location.
After making the changes, click Submit to confirm your changes. Refer to the section on Committing Your
Changes and Rebooting the Prestige to save your changes to permanent memory and make your changes
take effect.
Configuring Network Address Translation
Prestige 623 Series Dual-link ADSL Router
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