IP Addressing
IP
Address is short for Internet Protocol Address.
- It is a unique address assigned to each computing device in an IP network.
- ISP assigns IP Address to all the devices present on its network.
- Computing devices use IP Address to identify and communicate with other devices in the IP network.
Types
of IP Address
IP Addresses may be of the following two types
1.
Static IP Address-
- Static IP Address is an IP Address that once assigned to a network element Always remains the same.
- They are configured manually.
- Some ISPs do not provide static IP addresses.
- Static IP Addresses are more costly than dynamic IP Addresses
2. Dynamic IP Address
Dynamic IP Address is a temporarily assigned IP Address to a
network element.
- It can be assigned to a different device if it is not in use.
- DHCP or PPPoE assigns dynamic IP addresses.
IP
Address Format
IP
Address is a 32 bit binary address written as 4 numbers separated by dots.
The
4 numbers are called as octets where each octet has 8 bits.
The
octets are divided into 2 components- Net ID and Host ID.
Rules for assigning Host ID:
The Host ID is used to determine the host within any network. The Host ID is assigned based on the following rules:
- The Host ID must be unique within any network.
- The Host ID in which all the bits are set to 0 cannot be assigned as it is used to represent the network ID of the IP address.
- The Host ID in which all the bits are set to 1 cannot be assigned as it is reserved for the multicast address.
Rules for assigning Network ID:
If the hosts are located within the same local network, then they are assigned with the same network ID. The following are the rules for assigning Network ID:
- The network ID cannot start with 127 as 127 is used by Class A.
- The Network ID in which all the bits are set to 0 cannot be assigned as it is used to specify a particular host on the local network.
- The Network ID in which all the bits are set to 1 cannot be assigned as it is reserved for the multicast address.
Classes of IP Address-
All the classes of IP Address are summarized in the following table
