Operation Manual

Vigor2120 Series User’s Guide
148
request to.
 DHCP Server IP Address – It is available when
Enable Relay Agent is checked. Set the IP address of
the DHCP server you are going to use so the Relay
Agent can help to forward the DHCP request to the
DHCP server.
Enable Server - Let the router assign IP address to every
host in the LAN.
 Start IP Address - Enter a value of the IP address
pool for the DHCP server to start with when issuing IP
addresses. If the 1st IP address of your router is
192.168.1.1, the starting IP address must be
192.168.1.2 or greater, but smaller than
192.168.1.254.
 IP Pool Counts - Enter the maximum number of PCs
that you want the DHCP server to assign IP addresses
to. The default is 50 and the maximum is 253.
 Gateway IP Address - Enter a value of the gateway
IP address for the DHCP server. The value is usually
as same as the 1st IP address of the router, which
means the router is the default gateway.
 Lease Time - Enter the time to determine how long
the IP address assigned by DHCP server can be used.
 Clear DHCP lease for inactive clients periodically -
Whenever a DHCP client requests an IP address from
the LAN DHCP server, the server will give out an IP
to this client for a certain amount of time (e.g., 1 day).
However, even if this client only uses the IP for say 5
minutes, the server still "reserves" 1 day for that
client. Because a DHCP server only has a limited
number of IPs to lease to its DHCP clients, soon
enough all the IPs will be used out and then no one
will be able to get any IPs from this server anymore.
Therefore, this feature is used to get the IP back from
inactive clients (i.e. doesn't use the IP but the server
still reserves the IP for him).
DNS Server IP Address
DNS stands for Domain Name System. Every Internet host
must have a unique IP address, also they may have a
human-friendly, easy to remember name such as
www.yahoo.com. The DNS server converts the
user-friendly name into its equivalent IP address.
Primary IP Address -You must specify a DNS server IP
address here because your ISP should provide you with
usually more than one DNS Server. If your ISP does not
provide it, the router will automatically apply default DNS
Server IP address: 194.109.6.66 to this field.
Secondary IP Address - You can specify secondary DNS
server IP address here because your ISP often provides you
more than one DNS Server. If your ISP does not provide it,
the router will automatically apply default secondary DNS
Server IP address: 194.98.0.1 to this field.
The default DNS Server IP address can be found via Online