IP address planning in corporate intranet, you should master these 6 points!

Intranet is the implementation of Internet technology within an enterprise or a closed user group. Its basic communication protocol is the TCP/IP protocol, in which TCP enables orderly and reliable transmission of data on the intranet, and IP interconnects the various subnets in the intranet.

Each device in the intranet is identified by an IP address.

Therefore, before setting up an intranet, a unique IP address must be assigned to all devices on the network, including servers, clients, print servers, etc.

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Taking into account future expansion, maintenance and other issues, the IP address of the intranet should not only comply with popular international standards, but also be regular, easy to remember, and reflect the characteristics of the intranet.

The intranets of different units have their own characteristics, and the planning of IP addresses also needs to consider different factors.

Assume that an intranet consists of two subnets located in different geographical locations.

When planning the IP address of this intranet, the following aspects were considered:

1. Determine the type of intranet IP address

An IP address consists of 32 binary digits, 8 bits per group, divided into 4 groups, separated by ".".

Each IP address has two parts, namely the network identifier and the host identifier. The difference in the length of these two identifiers divides IP addresses into five categories. The commonly used categories are A, B, and C. The corresponding address ranges are (where X represents any number between 0 and 255)

• Class A: 1.XXX ~ 126.XXX
• Category B: 128.XXX ~ 191.XXX
• Category C: 192.XXX to 223.XXX

It is not difficult to see that

• Class A IP means there are many hosts on a few networks;
• Class B IP means that the network and host distribution are moderate;
• Class C IP means a small number of hosts on many networks.

When choosing an IP address type for an intranet, you should choose based on the number of subnets in the intranet and the size of each subnet.

Class C is selected here. The first three segments identify different networks, and the fourth segment identifies different hosts in a network.

In order to make the IP address reflect the characteristics of the intranet, we give practical meaning to each segment.

• The first segment is used to distinguish between backbone and non-backbone networks. The backbone network takes 192, and the non-backbone network takes 196;
• The second section distinguishes subnets in different geographical locations, with location A taking 1 and location B taking 2.

In this way, when the intranet is expanded and new subnets are added, the IP address planning is very easy to implement.

The subnet mask of all devices in the intranet uses the default value 255.255.255.0, and the mask is no longer used to divide subnets.

2. Plan the IP addresses of each switch port

The servers and clients in the network are directly or indirectly connected to the ports of the switch.

In each subnet, each port of the switch acts as a gateway.

In order to make the gateway IP address regular, the host identifier of the switch port IP address is all "1".

3. Plan the FDDI port IP address

In each subnet, FDDI is the backbone network.

There are two switches at site A, each with two FDDI ports, forming three FDDI dual rings.

The IP addresses of the FDDI ports of the two switches are set to 192.1.1.1, 192.1.2.1, 192.1.2.2, and 192.1.3.1 respectively.

Two of the FDDI ports in the same network segment are used to connect the two switches. Switch B has one FDDI port with the address set to 192.2.1.1.

4. Plan the Ethernet port IP address

The clients are connected to the Ethernet ports of the switch through the hub. If the clients on a hub share 10M bandwidth.

Which clients share the 10M bandwidth should be determined based on the specific applications of the intranet.

If the client has no special bandwidth requirements, bandwidth can be allocated according to the administrative unit or floor to which the client belongs.

Assuming that the clients are evenly distributed on each floor and have no special bandwidth requirements, the latter method is adopted, connecting the clients on the same floor to a hub.

The third segment of the Ethernet port IP address is used to pick up the mail server and print server, and ports 3 to 8 are connected to the clients on the corresponding floors respectively.

For example, the client on the third floor is connected to the third port of Ethernet through a hub.

The clients at site B are distributed on layers 2 to 6, and the IP addresses of the switch's eight Ethernet ports are set to 196.2.1.1 to 196.2.8.1 respectively.

5. Plan the server IP address

The server can be connected to the backbone network FDDI, monopolizing or sharing 100M bandwidth, or it can be connected to the Internet port of the switch, monopolizing 10M bandwidth.

The specific port to which the server is connected and the bandwidth it occupies are determined by the tasks the server performs in the intranet.

But no matter which port it is connected to, the server is in the same network as the switch port it is connected to.

That is, the network identifier of the server IP address is the same as the network identifier of the connected port.

Therefore, planning of the server IP address only requires planning of the host ID.

In this example, different host IDs are planned according to the types of servers in the intranet. The host ID of the database server is 20, the WEB server is 30, the mail server is 40, and the print server is 50.

For example, the database server connected to the FDDI port at site A has an IP address of 192.1.1.20; the mail server and print server connected to the first and second Ethernet ports have IP addresses of 196.1.1.40 and 196.1.2.50 respectively.

6. Plan client IP addresses

The client and the port of the connected switch are in the same network, and the planning of its IP address only requires planning of its host ID.

When making specific plans, you should try to make the host identifier reflect certain characteristics of the client in the intranet, such as the administrative unit to which it belongs or the specific physical location.

In the latter approach, the host ID directly references the room number in which it is located, because most clients have a one-to-one correspondence with room numbers.

For example, if a client computer at location A is located in Room 30 on the 3rd floor, its IP address is set to 196.1.3.30.

There are two points to note when choosing this method:

• First, when the room number is greater than 255, the host ID cannot be directly referenced, and other corresponding relationships should be considered.
• Second, the IP addresses of the clients are not continuous, because some rooms may have no clients, while other rooms may have more than one client. In order to facilitate the allocation of new client IP addresses in the future, the IP addresses of existing clients should be organized and recorded.
• In addition, if the intranet is to be connected to the Internet, before planning the intranet IP address, you should go to the relevant department to apply for the Internet IP address.

Since IP addresses on the Internet are relatively limited, the IP addresses applied for may not be enough to be allocated to every device on the intranet. In this case, it is still necessary to plan the IP addresses of the intranet.

The connection between the intranet and the Internet can be achieved through proxy servers and other means.