ZyXEL Communications ZyWALL 1000 Network Router User Manual


 
Chapter 10 Interface
ZyWALL USG 1000 User’s Guide
183
The ZyWALL cannot assign the first address (network address) or the last address
(broadcast address) in the subnet defined by the interface’s IP address and subnet mask.
For example, in the first entry, if the subnet mask is 255.255.255.0, the ZyWALL cannot
assign 50.50.50.0 or 50.50.50.255. If the subnet mask is 255.255.0.0, the ZyWALL cannot
assign 50.50.0.0 or 50.50.255.255. Otherwise, it can assign every IP address in the range,
except the interface’s IP address.
If you do not specify the starting address or the pool size, the interface the maximum range
of IP addresses allowed by the interface’s IP address and subnet mask. For example, if the
interface’s IP address is 9.9.9.1 and subnet mask is 255.255.255.0, the starting IP address
in the pool is 9.9.9.2, and the pool size is 253.
Subnet mask - The interface provides the same subnet mask you specify for the interface.
See Section 10.1.2 on page 180.
Gateway - The interface provides the same gateway you specify for the interface. See
Section 10.1.2 on page 180.
DNS servers - The interface provides IP addresses for up to three DNS servers that
provide DNS services for DHCP clients. You can specify each IP address manually (for
example, a company’s own DNS server), or you can refer to DNS servers that other
interfaces received from DHCP servers (for example, a DNS server at an ISP). These other
interfaces have to be DHCP clients.
It is not possible for an interface to be the DHCP server and a DHCP client simultaneously.
10.1.4.1 WINS
WINS (Windows Internet Naming Service) is a Windows implementation of NetBIOS Name
Server (NBNS) on Windows. It keeps track of NetBIOS computer names. It stores a mapping
table of your network’s computer names and IP addresses. The table is dynamically updated
for IP addresses assigned by DHCP. This helps reduce broadcast traffic since computers can
query the server instead of broadcasting a request for a computer name’s IP address. In this
way WINS is similar to DNS, although WINS does not use a hierarchy (unlike DNS). A
network can have more than one WINS server. Samba can also serve as a WINS server.
10.1.5 Ping Check Settings
The interface can regularly ping the gateway you specified (see Section 10.1.2 on page 180) to
make sure it is still available. You specify how often the interface pings the gateway, how long
to wait for a response before the attempt is a failure, and how many consecutive failures are
required before the ZyWALL stops routing to the gateway. The ZyWALL resumes routing to
the gateway the first time the gateway acknowledges the ping.
99.99.1.1 1023 99.99.1.1 - 99.99.4.255
120.120.120.100 100 120.120.120.100 - 120.120.120.199
Table 46 Example: Assigning IP Addresses from a Pool (continued)
START IP ADDRESS POOL SIZE RANGE OF ASSIGNED IP ADDRESS