ZyXEL Communications ZyWALL5UTM 4.0 User Manual

ZyWALL 5/35/70 Series User’s Guide

Chapter 5 LAN Screens

110

Multicast

Select IGMP V-1 or IGMP V-2 or None. IGMP (Internet Group Multicast Protocol) is 

a network-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.

DHCP Setup

DHCP 

DHCP (Dynamic Host Configuration Protocol, RFC 2131 and RFC 2132) allows 

individual clients (workstations) to obtain TCP/IP configuration at startup from a 

server. Unless you are instructed by your ISP, leave this field set to Server. When 

configured as a server, the ZyWALL provides TCP/IP configuration for the clients. 

When set as a server, fill in the IP Pool Starting Address and Pool Size fields.
Select Relay to have the ZyWALL forward DHCP requests to another DHCP 

server. When set to Relay, fill in the DHCP Server Address field.
Select None to stop the ZyWALL from acting as a DHCP server. When you select 

None, you must have another DHCP server on your LAN, or else the computers 

must be manually configured. 

IP Pool Starting 

Address

This field specifies the first of the contiguous addresses in the IP address pool.

Pool Size

This field specifies the size, or count of the IP address pool.

DHCP Server 

Address

Type the IP address of the DHCP server to which you want the ZyWALL to relay 

DHCP requests. Use dotted decimal notation. Alternatively, click the right mouse 

button to copy and/or paste the IP address.

Windows 

Networking 

(NetBIOS over 

TCP/IP)

NetBIOS (Network Basic Input/Output System) are TCP or UDP packets that 

enable a computer to connect to and communicate with a LAN. For some dial-up 

services such as PPPoE or PPTP, NetBIOS packets cause unwanted calls. 

However it may sometimes be necessary to allow NetBIOS packets to pass 

through to the WAN in order to find a computer on the WAN.

Allow between 

LAN and WAN

Select this check box to forward NetBIOS packets from the LAN to the WAN and 

from the WAN to the LAN. If your firewall is enabled with the default policy set to 

block WAN to LAN traffic, you also need to enable the default WAN to LAN firewall 

rule that forwards NetBIOS traffic.
Clear this check box to block all NetBIOS packets going from the LAN to the WAN 

and from the WAN to the LAN.

Allow between 

LAN and DMZ

Select this check box to forward NetBIOS packets from the LAN to the DMZ and 

from the DMZ to the LAN. If your firewall is enabled with the default policy set to 

block DMZ to LAN traffic, you also need to enable the default DMZ to LAN firewall 

rule that forwards NetBIOS traffic.
Clear this check box to block all NetBIOS packets going from the LAN to the DMZ 

and from the DMZ to the LAN.

Allow between 

LAN and WLAN

Select this check box to forward NetBIOS packets from the LAN to the WLAN and 

from the WLAN to the LAN. 
Clear this check box to block all NetBIOS packets going from the LAN to the WLAN 

and from the WLAN to the LAN.

Apply

Click Apply to save your changes back to the ZyWALL.

Reset

Click Reset to begin configuring this screen afresh.

Table 22   LAN  (continued)