Draytek VIGOR3220 SERIES, User Manual

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Vigor3220 Series User’s Guide 96
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.
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
Status:
If both the Primary IP and Secondary IP Address fields are left
empty, the router will assign its own IP address to local users
as a DNS proxy server and maintain a DNS cache.
If the IP address of a domain name is already in the DNS
cache, the router will resolve the domain name immediately.
Otherwise, the router forwards the DNS query packet to the
external DNS server by establishing a WAN (e.g. DSL/Cable)