Chapter 6 The LAN Configuration Screens
User’s Guide
68
6.7.3 LAN TCP/IP
The WiMAX Modem has built-in DHCP server capability that assigns IP addresses and DNS
servers to systems that support DHCP client capability.
The LAN parameters of the WiMAX Modem are preset in the factory with the following
values:
• IP address of 192.168.100.1 with subnet mask of 255.255.255.0 (24 bits)
• DHCP server enabled with 32 client IP addresses starting from 192.168.1.33.
These parameters should work for the majority of installations. If your ISP gives you explicit
DNS server address(es), see
Section 6.3 on page 61.
6.7.4 DNS Server Address
DNS (Domain Name System) is for mapping a domain name to its corresponding IP address
and vice versa. The DNS server is extremely important because without it, you must know the
IP address of a machine before you can access it. The DNS server addresses that you enter in
the DHCP setup are passed to the client machines along with the assigned IP address and
subnet mask.
There are two ways that an ISP disseminates the DNS server addresses. The first is for an ISP
to tell a customer the DNS server addresses, usually in the form of an information sheet, when
s/he signs up. If your ISP gives you the DNS server addresses, enter them in the DNS Server
fields in DHCP Setup, otherwise, leave them blank.
Some ISPs choose to pass the DNS servers using the DNS server extensions of PPP IPCP (IP
Control Protocol) after the connection is up. If your ISP did not give you explicit DNS servers,
chances are the DNS servers are conveyed through IPCP negotiation. The WiMAX Modem
supports the IPCP DNS server extensions through the DNS proxy feature.
If the Primary and Secondary DNS Server fields in the LAN Setup screen are not specified,
for instance, left as 0.0.0.0, the WiMAX Modem tells the DHCP clients that it itself is the DNS
server. When a computer sends a DNS query to the WiMAX Modem, the WiMAX Modem
forwards the query to the real DNS server learned through IPCP and relays the response back
to the computer.
Please note that DNS proxy works only when the ISP uses the IPCP DNS server extensions. It
does not mean you can leave the DNS servers out of the DHCP setup under all circumstances.
If your ISP gives you explicit DNS servers, make sure that you enter their IP addresses in the
LAN Setup screen. This way, the WiMAX Modem can pass the DNS servers to the computers
and the computers can query the DNS server directly without the WiMAX Modem’s
intervention.
6.7.5 RIP Setup
RIP (Routing Information Protocol) allows a router to exchange routing information with
other routers. The RIP Direction field controls the sending and receiving of RIP packets.
When set to:
• Both - the WiMAX Modem will broadcast its routing table periodically and incorporate
the RIP information that it receives.
