E-6 User’s Reference GuideThere are two schemes for distributing the remaining IP addresses: Manually give each computer an address Let the Netopia R3100 automatically distribute the addressesThese two methods are not mutually exclusive; you can manually issue some of the addresses while the restare 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 distributingthe addresses. This is particularly true if you have many addresses to distribute. You only need to enterinformation once, rather than having to repeatedly enter it on each host separately. This also reduces thepotential for misconfiguring hosts.Another reason to use the Netopia R3100 as an address server is that it will only distribute addresses to hoststhat need to use them.All Netopia R3100s come with an integrated Dynamic Host Control Protocol (DHCP) server. Some routers alsocome with a Macintosh Internet Protocol (MacIP) server. These servers provide a means of distributing IPaddresses 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 howworkstations lease, renew, and release their IP addresses. This information will be helpful in determiningdynamic address allocation for a network.The term “lease” describes the action of a workstation requesting and using an IP address. The address isdynamic 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, theworkstation talks to the DHCP or MacIP server and renews the lease on that IP address. This renewal allowsthe 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 hasbeen shut down. IP addresses can be manually released as well. The IP address goes back into the DHCP orMacIP address pool to be reassigned to another workstation as needed.Technical note on subnet maskingNote: The IP address supplied by the Netopia R3100 will be a unique number. You may wish to replace thisnumber with a number that your ISP supplies if you are configuring the router for a static IP address. Theautomatic IP mask supplied by SmartStart is a Class C address. However, the Netopia R3100 and all deviceson the same local network must have the same subnet mask. If you require a different class address, you mayedit the IP Mask field to enter the correct address. Refer to the table below.Number of Devices (other thanNetopia R3100) on Local NetworkLargest Possible Ethernet SubnetMask1 255.255.255.2522-5 255.255.255.2486-13 255.255.255.24014-29 255.255.255.224
