E-6 User’s Reference Guide

There are two schemes for distributing the remaining IP addresses:

Manually give each computer an address

Let the Netopia R3100 automatically distribute the addresses

These two methods are not mutually exclusive; you can manually issue some of the addresses while the rest are distributed by the Netopia R3100. Using the Router in this way allows it to function as an address server.

One reason to use the Netopia R3100 as an address server is that it takes less time than manually distributing the addresses. This is particularly true if you have many addresses to distribute. You only need to enter information once, rather than having to repeatedly enter it on each host separately. This also reduces the potential for misconfiguring hosts.

Another reason to use the Netopia R3100 as an address server is that it will only distribute addresses to hosts that need to use them.

All Netopia R3100s come with an integrated Dynamic Host Control Protocol (DHCP) server. Some routers also come with a Macintosh Internet Protocol (MacIP) server. These servers provide a means of distributing IP addresses to either a Mac or PC workstation as needed.

When setting up the DHCP or MacIP servers in the Netopia R3100, it is necessary to understand how workstations lease, renew, and release their IP addresses. This information will be helpful in determining dynamic address allocation for a network.

The term “lease” describes the action of a workstation requesting and using an IP address. The address is dynamic and can be returned to the address pool at a later time.

The term “renew” refers to what the workstations do to keep their leased IP address. At certain intervals, the workstation talks to the DHCP or MacIP server and renews the lease on that IP address. This renewal allows the workstation to keep and use the assigned IP address until the next renewal period.

The term “release” refers to a situation where the workstation is no longer using its assigned IP address or has been shut down. IP addresses can be manually released as well. The IP address goes back into the DHCP or MacIP address pool to be reassigned to another workstation as needed.

Technical note on subnet masking

Note: The IP address supplied by the Netopia R3100 will be a unique number. You may wish to replace this number with a number that your ISP supplies if you are configuring the router for a static IP address. The automatic IP mask supplied by SmartStart is a Class C address. However, the Netopia R3100 and all devices on the same local network must have the same subnet mask. If you require a different class address, you may edit the IP Mask field to enter the correct address. Refer to the table below.

Number of Devices (other than

Netopia R3100) on Local Network

Largest Possible Ethernet Subnet

Mask

 

1

255.255.255.252

 

 

 

 

2-5

255.255.255.248

 

 

 

 

6-13

255.255.255.240

 

 

 

 

14-29

255.255.255.224

 

 

 

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Netopia R3100 manual Technical note on subnet masking