Netopia 4541 User Manual
Page 59
IP Setup 8-3
The Netopia 4541/4542 suppor ts multiple IP subnets on the Ethernet inter face. You may want to
configure multiple IP subnets to ser vice more hosts than are possible with your primar y subnet. It is not
always possible to obtain a larger subnet from your ISP. For example, if you already have a full Class C
subnet, your only option is multiple Class C subnets, since it is vir tually impossible to justify a Class A or
Class B assignment.
If you are using NAT, you can use the reser ved Class A or Class B subnet.
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Select Default IP Gateway and enter the IP address for a default gateway. This can be the address of any
major router accessible to the Netopia 4541/4542.
A default gateway should be able to successfully route packets when the Netopia 4541/4542 doesn’t
know how to route to the intended recipient’s IP address. Typically, a default gateway is the ISP’s router.
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Select Primary Domain Name Server and enter the IP address for a domain name ser ver. The domain
name ser ver matches the alphabetic addresses favored by people (for example, robin.hood.com) to the IP
addresses actually used by IP routers (for example, 163.7.8.202).
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If a secondar y DNS ser ver is available, select Secondary Domain Name Server and enter its IP address.
The secondar y DNS ser ver is used by the Netopia 4541/4542 when the primar y DNS ser ver is
inaccessible. Entering a secondar y DNS is useful but not necessar y.
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Select Domain Name and enter your network’s domain name (for example, netopia.com). Netopia strongly
recommends that you enter a domain name.
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Routing Information Protocol (RIP) is needed if there are IP routers on other segments of your Ethernet
network that the Netopia 4541/4542 needs to recognize. If this is the case select Receive RIP and select
v1, v2, or Both from the pop-up menu. With Receive RIP set to v1, the Netopia 4541/4542’s Ethernet por t
will accept routing information provided by RIP packets from other routers that use the same subnet mask.
Set to v2, the Netopia 4541/4542 will accept routing information provided by RIP packets from other
routers that use different subnet masks. Set to Both, the Netopia 4541/4542 will accept information from
either RIP v1 or v2 routers.
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If you want the Netopia 4541/4542 to adver tise its routing table to other routers via RIP, select Transmit
RIP and select v1, v2 (broadcast), or v2 (multicast) from the pop-up menu. With Transmit RIP v1 selected,
the Netopia 4541/4542 will generate RIP packets only to other RIP v1 routers. With Transmit RIP v2
(broadcast) selected, the Netopia 4541/4542 will generate RIP packets to all other hosts on the network.
With Transmit RIP v2 (multicast) selected, the Netopia 4541/4542 will generate RIP packets only to other
routers capable of recognizing RIP v2 packets.
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Select Static Routes to manually configure IP routes. See the section
below.
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Select Network Address Translation to configure advanced MultiNAT features. See
.
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If you select IP Address Serving you will be taken to the IP Address Ser ving screen (see
). Since no two hosts can use the same IP address at the same time, make sure
that the addresses distributed by the Netopia 4541/4542 and those that are manually configured are not
the same. Each method of distribution must have its own exclusive range of addresses to draw from.