62 CHAPTER 4: BASIC SETTINGS OF THE F IREWALLSubnet MaskEnter the Subnet mask for your network. This value will be given out bythe DHCP server and will be used by client devices to determine theextent of your network.Domain NameType the registered domain name for the network in the Domain Namebox, for example: 3com.com. If you do not have a Domain Name leavethis blank.DNS ServersA DNS Server translates human readable host names into the numeric IPaddresses used by computers to route information to the correctmachine. You can use multiple DNS servers to improve performance andreliability. To specify these manually select the Specify Manually radio boxand type the IP address of the DNS Server(s) in these boxes.Alternatively, if you are using NAT with DHCP client you can select the SetDNS Servers by Internet Firewalls DHCP Client to have these fields setautomatically.Dynamic Ranges When a client makes a request for an IP address, the Firewall’s DHCPserver leases an address from the Dynamic Ranges.Prior to offering an address from the Dynamic Range to a requestingclient, the Firewall first verifies that the address is not already in use byanother machine on the LAN.To create a range of dynamic IP addresses to be assigned to requestingclients, type the starting number in the Range Start box, the endingaddress in the Range End box and then click Update.Allow BootP clients to use rangeClick this check box to have Dynamic BootP clients configured when theyboot. Dynamic BootP clients are BootP clients that do not have an IPaddress assigned to their MAC address. They are similar to DHCP clientswith the exception that leases are not supported.DUA1611-0AAA02.book Page 62 Thursday, August 2, 2001 4:01 PM
