Hypertec ISDN 10T Router Internet and Intranet Connection Profiles, IP Address and Subnet Mask

Concepts and Principles of Operation

Internet and Intranet Connection Profiles

Hypertec ISDN 10T Router maintains two connection profiles one for Internet and the other for Intranet. The Internet connection by definition is for users to reach Internet, the Intranet connection is made between two offices. The Internet profile contains the configuration parameters required by the Internet connection. The categories available under Internet profile are : ISDN, PPP, IP, and NAT. The Intranet profile contains the configuration parameters required by the Intranet connection. The categories available under the Intranet profile are ISDN, PPP, IP, IPX, and Bridge. NAT is intended for Internet only where security and ISP monthly charge is of concerned. The IPX and Bridging functions are intended for Intranet where protocols other than IP may be required. Users should make sure not to configure conflicting information between these two profiles, such as setting the same remote IP address or ISDN dialing number to both profiles. These two types of connections are shown in Figure 0-1, Internet and Intranet Connections.

Figure 0-1, Internet and Intranet Connections

IP Address and Subnet Mask

The address used for IP routing is the IP address. An IP Address is a 32-bit address which must be assigned to every host that wants to use IP to communicate across the Internet. If you are connecting to the Internet, in general the IP addresses of the computers and router are assigned from your Internet service provider unless Network Address Translation (NAT) is used which we will discuss later.

The IP address are specified in a.b.c.d where a,b,c,d are each decimal numbers between 0 and 255 with some restrictions applied. The Hypertec Router Ethernet IP address must be on the same network as your PCs on the LAN. A network can be subnetted into one or more physical networks which form a subset of the main network. The Subnet Mask is a number identifying a subnet within a network.

Routing Table

In order to move data from port to port, the router has to make routing decision based on the routing table. Each routing entry describes what network can be reached through which interface via a certain gateway.

Some routing entries are system created based on the router interface configuration. Some routing entries may be created by users & classified as static routes, and other may be created based on the information learned from the router protocol (eg. RIP). Static Routes are a cost-saving feature which avoids running RIP over WAN links. The active route is advertised by Hypertec Router via RIP (if enabled) on its LAN interface. For the Hypertec ISDN router, the default route created by the system is automatically set toward Internet remote router. Users need to enter static route entries only when there are multiple subnets at the Intranet remote end.

IP Address, Un-Numbered, or Numbered

9