ZyXEL Communications ZyWall USG 50-H Series, Руководство пользователя

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Chapter 8 Interface
ZyWALL USG 50-H User’s Guide
159
MTU Maximum Transmission Unit. Type the maximum size of each data packet, in
bytes, that can move through this interface. If a larger packet arrives, the
ZyWALL divides it into smaller fragments. Allowed values are 576 - 1500.
Usually, this value is 1500.
DHCP Settings The DHCP settings are available for the LAN and DMZ interfaces.
DHCP Select what type of DHCP service the ZyWALL provides to the network.
Choices are:
None - the ZyWALL does not provide any DHCP services. There is already a
DHCP server on the network.
DHCP Relay - the ZyWALL routes DHCP requests to one or more DHCP
servers you specify. The DHCP server(s) may be on another network.
DHCP Server - the ZyWALL assigns IP addresses and provides subnet mask,
gateway, and DNS server information to the network. The ZyWALL is the DHCP
server for the network.
These fields appear if the ZyWALL is a DHCP Relay .
Relay Server 1 Enter the IP address of a DHCP server for the network.
Relay Server 2 This field is optional. Enter the IP address of another DHCP server for the
network.
These fields appear if the ZyWALL is a DHCP Server .
IP Pool Start
Address Enter the IP address from which the ZyWALL begins allocating IP addresses. If
you want to assign a static IP address to a specific computer, click
Add Static
DHCP .
If this field is blank, the Pool Size must also be blank. In this case, the ZyWALL
can assign every IP address allowed by the interface’s IP address and subnet
mask, except for the first address (network address), last address (broadcast
address) and the interface’s IP address.
Pool Size Enter the number of IP addresses to allocate. This number must be at least one
and is limited by the interface’s
Subnet Mask . For example, if the Subnet Mask
is 255.255.255.0 and IP Pool Start Address is 10.10.10.10, the ZyWALL can
allocate 10.10.10.10 to 10.10.10.254, or 245 IP addresses.
If this field is blank, the
IP Pool Start Address must also be blank. In this case,
the ZyWALL can assign every IP address allowed by the interface’s IP address
and subnet mask, except for the first address (network address), last address
(broadcast address) and the interface’s IP address.
First DNS Server
Second DNS
Server
Third DNS
Server Specify the IP addresses of a maximum of three DNS servers that the network
can use. The ZyWALL provides these IP addresses to DHCP clients. Use one of
the following ways to specify these IP addresses.
Custom Defined - enter a static IP address.
From ISP - select the DNS server that another interface received from its DHCP
server.
ZyWALL - the ZyWALL uses the IP address of this interface and works as a
DNS relay.
First WINS
Server, Second
WINS Server Type the IP address of the WINS (Windows Internet Naming Service) server
that you want to send to the DHCP clients. The WINS server keeps a mapping
table of the computer names on your network and the IP addresses that they
are currently using.
Lease time Specify how long each computer can use the information (especially the IP
address) before it has to request the information again. Choices are:
infinite - select this if IP addresses never expire.
days, hours, and minutes - select this to enter how long IP addresses are
valid.
Table 45 Network > Interface > Ethernet > Edit
LABEL DESCRIPTION