Zhone 2000 ユーザーガイド

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NAT Local Server Configuration
A NAT Local Server entry is used when the local device shares its IP address 
with the WAN port of the IAD. Only the configured protocol and port will be 
visible from the Internet. When the Local Server is configured, the following 
information must be entered:
Translated IP address 
− local IP address, as seen from the LAN.
Protocol 
− TCP, UDP, AH, ESP, or both UDP and TCP.
Translated Port Number 
− port number on which the local server sees the 
service (UDP and TCP only).
Standard Port Number 
− port number on which the Internet sees the service 
(UDP and TCP only).
For current port number assignments, please see http://www.iana.org/
assignments/port-numbers.
Note that TCP port 1723 is used to select Point-to-Point Tunneling Protocol 
(PPTP) and TCP port 1720 is used to select ViaVideo. When using ViaVideo 
units through NAT, the following limitations apply.
Only one Via Video inside of NAT may accept calls.
All ViaVideo units in the network must be configured to use fixed ports 3230 
− 3235.
All ViaVideo units inside of NAT must be configured to use NAT and must 
have the IAD’s WAN address configured.
If Internet access of a local Telnet server at TCP port 23 is desired, it will be 
necessary to reconfigure the Telnet server port of the IAD. Refer to 
“Configure Port IP Address” on page 4-82 for further information.
NAT Alias Configuration
A NAT Alias entry is used when the local device is assigned a unique IP 
address from the WAN port of the IAD. The local device will be totally 
accessible from the Internet. When the Alias entry is configured, the 
following information must be entered:
Local IP Address
 − the local IP address as seen from the LAN.
Internet IP Address 
− the IP address of the device as seen from the Internet.
When configuring a NAT Alias entry, the alias’s Internet IP address must also 
be configured on the WAN port. This must be configured with an IP mask of 
255.255.255.255 if the alias’s Internet IP address is on the same subnet as the 
IAD’s WAN IP address. If the alias’s Internet IP address is on a subnet 
different from the IAD’s WAN IP address, the proper subnet mask should be 
used. Refer to “Configure Port IP Address” on page 4-82 for further 
information.
IP Filtering
IP Filtering controls IP traffic traveling through an interface by selectively 
passing or discarding IP packets based on criteria expressed in the form of a