Network Address Planning

The Internet Protocol especially IPv4 is now in used almost for all business and personal digital communications as well as data centers, telephones network, and industrial control systems. Now, the Internet protocols have adopted for 3G, 4G, and 4G LTE mobile systems and are a serious enabler for the Internet of Things. The world using billions of IP addresses currently.

The network administrator and network engineers make IP address planning documentation. The document shows the distribution of IP addresses between the network devices. The IP address distribution is also based on network architecture or topology in a way that supports the required services. There are multiple levels of network address planning.

Setting up network subnet requires a check of both the needs of an organization’s network usage and how the subnet will organize. Performing a network address planning, a study is in fact, the starting point. As soon as you effectively carry out an IP network infrastructure, you have to find your IP addressing requirements. The address plan includes determining the needs of each subnet. Some of the things that you need to consider include:

  • Will you need a public or private IP address range on the internal network?

  • Does the network need multiple subnets?

  • How many hosts per subnet?

  • How host addresses will be assigned, static or automatic?

  • Which hosts will need static IP addresses?

  • Which hosts can use DHCP for obtaining their addressing information?

The subnet size involves planning the number of hosts that will need IP host addresses in each subnet of the subdivided private network.  For example, in an organization network design, you may consider how many hosts needed in the Management LAN, Finance LAN, Sales LAN, HR LAN, and Engineer department LAN. In a home network, a consideration may done by the number of hosts.

We already discussed the private IP address range in previous lessons. The use of private addresses on a LAN is the selection of the network administrator and desires careful to sure that enough host addresses will available for the now known hosts and for future expansion. The ranges of private IP address for different classes are the following:

Class-A – with a subnet mask of or /8

Class-B – with a subnet mask of or /12

Class-C – with a subnet mask of or /16

You should know the IP address requirements will decide the range or ranges of host addresses you carry out. Knowing IP address need is also necessary for the network administrator to decide the host addresses. Subnetting the chosen private IP address space will give the host addresses to cover your network needs. Typically, the service provider allocates public addresses. For subnetting of public IP address the same principles would apply, this is the responsibility of the service provider.

network address planning

Planning to Address the Network

The four primary segments for planning address allocation are Management LAN, Finance LAN, Sales LAN, HR LAN and Engineer department LAN in our example. To Preventing the IP address conflict required each host in an internetwork must have a unique address. An IP address conflict resulting in access issues for both hosts. Without the proper network address planning and documentation, an address could be assigned to more than one host.

Some hosts like servers provide and share a resource with other hosts. The IP address assigned to a server can control access to the server. If the address is randomly assigned and not static, controlling access is more difficult.  Monitoring performance and security of hosts means network traffic examined for source IP addresses that are generating or receiving too many packets. The proper network address planning of network addressing, problematic network devices also can easily troubleshoot.

Assigning Addresses to Network Devices

There are different types of devices we can find in the network that requires IP addresses including:

  • End-user clients– Many network administrators allocate addresses automatically using DHCP to their end-user clients. The automatic IP address assignment reduces the load on network support staff and also eliminates the IP address assignment errors. The DHCP has only leased the IP addresses for a time. Changing the subnetting scheme is easy and the administrator just needs to reconfigure the DHCP server, and the clients must renew their IP addresses.
  • Servers and peripherals– The servers give service and share resource to other hosts inside the network and outside the network. The IP address assigned to a server can be used also to control access to that server. So the address must be static to give service and share the resources. Also, use a consistent numbering system for these devices.
  • Servers that are accessible from the Internet–Some servers must be made available to the remote users from the internet. In the major cases, these servers are assigned private IP addresses internally, and the router at the edge of the network must be configured to translate the internal address into a public IP address.
  • Intermediary network devices– These network devices have assigned addresses for network management, as well as for monitoring and security. These devices should have statically assigned IP addresses.
  • Gateway– Routers have an IP address assigned to every interface which serves as the gateway for the hosts in that network. Typically, the router interface uses both the lowest or highest address in the network.