ZyXEL Communications ZyWall 10W User Manual page 74

ZyWALL Series Internet Security Gateway
LABEL
Pool Size
DNS Servers Assigned by DHCP Server
The ZyWALL passes a DNS (Domain Name System) server IP address (in the order you specify here) to
the DHCP clients. The ZyWALL only passes this information to the LAN DHCP clients when you select the
DHCP Server check box. When you clear the DHCP Server check box, DHCP service is disabled and you
must have another DHCP sever on your LAN, or else the computers must have their DNS server
addresses manually configured.
First DNS Server
Second DNS
Server
Third DNS Server
LAN TCP/IP
IP Address
IP Subnet Mask
5-4
This field specifies the size, or count of the IP address pool.
Select From ISP if your ISP dynamically assigns DNS server information (and the
ZyWALL's WAN IP address). The field to the right displays the (read-only) DNS
server IP address that the ISP assigns.
Select User-Defined if you have the IP address of a DNS server. Enter the DNS
server's IP address in the field to the right. If you chose User-Defined, but leave the
IP address set to 0.0.0.0, User-Defined changes to None after you click Apply. If
you set a second choice to User-Defined, and enter the same IP address, the
second User-Defined changes to None after you click Apply.
Select DNS Relay to have the ZyWALL act as a DNS proxy. The ZyWALL's LAN IP
address displays in the field to the right (read-only). The ZyWALL tells the DHCP
clients on the LAN that the ZyWALL itself is the DNS server. When a computer on
the LAN sends a DNS query to the ZyWALL, the ZyWALL forwards the query to the
ZyWALL's system DNS server (configured in the SYSTEM General screen) and
relays the response back to the computer. You can only select DNS Relay for one of
the three servers; if you select DNS Relay for a second or third DNS server, that
choice changes to None after you click Apply.
Select None if you do not want to configure DNS servers. If you do not configure a
DNS server, you must know the IP address of a computer in order to access it.
Type the IP address of your ZyWALL in dotted decimal notation 192.168.1.1 (factory
default).
The subnet mask specifies the network number portion of an IP address. Your
ZyWALL will automatically calculate the subnet mask based on the IP address that
you assign. Unless you are implementing subnetting, use the subnet mask
computed by the ZyWALL 255.255.255.0.
Table 5-1 IP
DESCRIPTION
LAN Screens