9-6 User’s Reference GuideWhen using numbered interfaces, the Netopia Router will use its local WAN IP address and subnet mask tosend packets to the remote router. Both routers have WAN IP addresses and subnet masks associatedwith the connection.6. If your ISP uses unnumbered (system-based) routing, select Remote IP Address and enter the IP addressyour ISP gave you. Then select Remote IP Mask and enter the IP subnet mask of the remote site you willconnect to.Note: When using unnumbered interfaces, the Netopia Router will use either its local Ethernet IP addressor its NAT (Network Address Translation) address (if so configured) and subnet mask to send packets to theremote router. Neither router has a WAN IP address or subnet mask associated with this connection. Thesedefault addresses will request that the remote router dynamically assign an address at the time theconnection is made.7. When your Netopia R7100 connects to the ISP, the remote router assigns your Netopia R7100 an IPaddress that external users use to communicate with your network.The following Quick View screen shows an example in which 192.168.100.6 is assigned to the NetopiaR7100. “NAT” indicates that the address was assigned dynamically by Network Address Translation.Internal users can access the Internet as they always do; the external Internet, however, views all traffic fromthe internal network as originating from 192.168.100.6 and all traffic your network receives is addressed to192.168.100.6.Associating port numbers with nodesWhen an IP client such as a Netscape Navigator or Microsoft Internet Explorer, wants to establish a sessionwith an IP server such as a Web server, the client machine must know the IP address to use and the TCPservice port where the traffic is to be directed.For example, a Web browser locates a Web server by using a combination of the IP address and TCP port thatthe client machine has set up.Quick View 12/11/1998 12:45:44 PMDefault IP Gateway: 0.0.0.0 CPU Load: 2% Unused Memory: 952 KBDomain Name Server: 0.0.0.0Domain Name: None Provided LocalTalk Address: 34448:149----------------MAC Address--------IP Address-------IPX Address---EtherTalk---Ethernet Hub: 00-00-c5-70-03-48 192.168.1.1 34449:150SDSL WAN1: 00-00-c5-70-03-4a 0.0.0.0Current DSL StatusProfile Name----------Rate--%Use-Remote Address-----Est.-More Info------------ISP P1 10% IP 92.163.4.1 Lcl NAT 192.168.100.6LED StatusPWR-+-----WAN1------+--CON--AUX--+-----WAN2------+--EN--+--------LEDS---------LNK RDY CH1 CH2 LNK LNK LNK RDY CH1 CH2 DATA | '-'= Off 'G'= Green
