ZyXEL Communications ZyWALL5UTM 4.0 User Manual

ZyWALL 5/35/70 Series User’s Guide

Chapter 7 WAN Screens

148

Enable NAT 

(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). 
Select this checkbox to enable NAT.
For more information about NAT see 

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 ZyWALL will broadcast its routing table 

periodically. 
When set to Both or In Only, the ZyWALL will incorporate RIP information that it 

receives.
When set to None, the ZyWALL 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 ZyWALL 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.

Enable Multicast

Select this check box to turn on IGMP (Internet Group Multicast Protocol). IGMP is 

a network-layer protocol used to establish membership in a Multicast group - it is 

not used to carry user data.

Multicast Version

Choose None (default), IGMP-V1 or IGMP-V2. IGMP (Internet Group Multicast 

Protocol) is a session-layer protocol used to establish membership in a Multicast 

group – it is not used to carry user data. IGMP version 2 (RFC 2236) is an 

improvement over version 1 (RFC 1112) but IGMP version 1 is still in wide use. If 

you would like to read more detailed information about interoperability between 

IGMP version 2 and version 1, please see sections 4 and 5 of RFC 2236.

Spoof WAN MAC 

Address

You can use the factory assigned default MAC Address or cloning the MAC 

address from a computer on your LAN. 
Otherwise, select the check box next to Spoof WAN MAC Address and enter the 

IP address of the computer on the LAN whose MAC you are cloning. Once it is 

successfully configured, the address will be copied to the rom file (ZyNOS 

configuration file). It will not change unless you change the setting or upload a 

different ROM file. 

Clone the 

computer’s MAC 

address – IP 

Address

Enter the IP address of the computer on the LAN whose MAC you are cloning.
It is recommended that you clone the MAC address prior to hooking up the WAN 

port.

Apply

Click Apply to save your changes back to the ZyWALL.

Reset

Click Reset to begin configuring this screen afresh.

Table 41   WAN: PPTP Encapsulation