ZyXEL g-2000 plusv2 ユーザーガイド

ZyXEL G-2000 Plus v2 User’s Guide

Chapter 7 WAN

109

Network Address 

Translation

Network Address Translation (NAT) allows the translation of an Internet 

protocol address used within one network (for example a private IP address 

used in a local network) to a different IP address known within another network 

(for example a public IP address used on the Internet). 
Choose None to disable NAT.
Choose SUA Only if you have a single public IP address. SUA (Single User 

Account) is a subset of NAT that supports two types of mapping: Many-to-One 

and Server. 
Choose Full Feature if you have multiple public IP addresses. Full Feature 

mapping types include: One-to-One, Many-to-One (SUA/PAT), Many-to-

Many Overload, Many- One-to-One and Server. When you select Full 

Feature you must configure at least one address mapping set!
For more information about NAT refer to the NAT chapter in this User's Guide.

Max NAT/Firewall 

Session Per User 

Type a number ranging from 1 to 2048 to limit the number of NAT/firewall 

sessions that a host can create.

Metric (PPPoE and 

PPTP only)

This field sets this route's priority among the routes the ZyXEL device uses. 
The metric represents the "cost of transmission". A router determines the best 

route for transmission by choosing a path with the lowest "cost". RIP routing 

uses hop count as the measurement of cost, with a minimum of "1" for directly 

connected networks. The number must be between "1" and "15"; a number 

greater than "15" means the link is down. The smaller the number, the lower 

the "cost".

Max NAT/Firewall 

Session Per User

Type a number ranging from 1 to 2048 to limit the number of NAT/firewall 

sessions that a host can create.

Private (PPPoE and 

PPTP only)

This parameter determines if the ZyXEL device will include the route to this 

remote node in its RIP broadcasts. If set to Yes, this route is kept private and 

not included in RIP broadcast. If No, the route to this remote node will be 

propagated to other hosts through RIP broadcasts.

RIP Direction

RIP (Routing Information Protocol) allows a router to exchange routing 

information with other routers. The RIP Direction field controls the sending 

and receiving of RIP packets. 
Choose Both, None, In Only or Out Only.
When set to Both or Out Only, the ZyXEL device will broadcast its routing 

table periodically. 
When set to Both or In Only, the ZyXEL device will incorporate RIP 

information that it receives.
When set to None, the ZyXEL device will not send any RIP packets and will 

ignore any RIP packets received. 
By default, RIP Direction is set to Both.

RIP Version

The RIP Version field controls the format and the broadcasting method of the 

RIP packets that the ZyXEL device sends (it recognizes both formats when 

receiving). 
Choose RIP-1, RIP-2B or RIP-2M.
RIP-1 is universally supported; but RIP-2 carries more information. RIP-1 is 

probably adequate for most networks, unless you have an unusual network 

topology. Both RIP-2B and RIP-2M sends the routing data in RIP-2 format; the 

difference being that RIP-2B uses subnet broadcasting while RIP-2M uses 

multicasting. Multicasting can reduce the load on non-router machines since 

they generally do not listen to the RIP multicast address and so will not receive 

the RIP packets. However, if one router uses multicasting, then all routers on 

your network must use multicasting, also. By default, the RIP Version field is 

set to RIP-1.

Table 37   WAN: IP