IP Address

The IPID is the Identification field of the IP protocol packet header which a;long with the source address uniquely identifies the packet. The IPID is used to reassemble the packet should it be fragmented. Every fragement of the packet will then have the same IPID for the destination device identify them all to be a simgle packet.

The IPID is primarily used in the Idle Port Scanning by a hacker where he spoofs a victims IP address to then use it to scan a target network or system. Various Operating Systems generate these IPIDs in different ways.

Static IP is also called as permanent address assigned to each device in a network, whereas Dynamic IP, a temporary address assigned to the device via DHCP software. IP address assigned to your service by your cable or DSL Internet provider is typically dynamic IP. In routers and operating systems, the default configuration for clients is dynamic IP

IP address or Internet Protocol address is the address of a device attached to an IP network (TCP/IP network). It is a must for every client, server and network device to have a unique IP address for each network connection (network interface). Every IP packet contains a source IP address and a destination IP address. As a device moves from one network to another, its IP address changes.

Private address: these IP addresses are used exclusively within a private network and not for public to see.

Public Address: these are registered IP addresses used for public.

Each IP address has a network address and a host address. IP addresses are expressed in four sets of three numbers, separated with dots. Each set is called as an octet because when converted to binary; it denotes eight binary.

Network Address Translation acts as an agent between the Internet and a local network. It is a dynamic method which is used to minimize Internet connectivity needs. Network address translation describes the rewriting of the Internet Protocol (IP) addresses of data packets so that multiple transmissions require only one IP address.

Subnet adds one level to the way IP address is represented. It logically organizes the network. For instance, it can logically group computers belongs to the finance department.

A public IP address allows equipment accessible to everyone on the internet. A private IP address is for private use within the network and allows many more PCs to be connected. If you are using a private IP and wants VOIP, you need to change to a public IP address.

IP multicast technology reduces traffic by sending stream of information to many recipients at one go. Video conferencing, stock quotas are the examples based on IP multicast.

MTU specifies the largest amount of data that can be transferred across a network.

Address Resolution Protocol ARP, is responsible for mapping an IP address to its corresponding physical network address. It is mostly seen on Ethernet network.

Routing protocol specifies how the routers communicate, disseminating the information which enables the routers to be selected between two nodes in a network.

Routing protocol interacts and informs the hardware that is needed to transmit the data between transmitter and the receiver for transmission over network.

Each IP address is 32 bit long. In human language the IP addresses are written in dotted decimal notation. These are then converted to binary by the computer. Each IP address has two parts: Network identifier or a network ID and host ID. The current internet protocol standard is IPV4. The IP addresses are divided into three classes: a class A network, a class B network, and a class C network. Class A being the largest. The four digit numbers in an IPV4 address, each network of class A will have different first number, and then its network will be addressed by the rest of the three numbers, or three bytes. The IP addresses identify a machine to deliver packets and load web pages.

When a source sends a packet to a destination, this packet has a specific path or route it follows. Different routing protocols are used to find the shortest path to the destination. The protocols maintain routing tables. Routing tables consist of a set of rules used to determine where these packets will travel. When a packet is received, a network device examines the packet and matches it to the routing table entry providing the best match for its destination. The packet keeps hopping until it reaches its destination.

A Domain Name system is used to convert the names of the website on the internet to IP addresses. The domain names for each IP addresses are stored in a database that is distributed across different servers. A domain name space consists of a tree of domain names. The tree has zones. Zones consist of a collection of connected nodes. These nodes are served by a name server. A domain name is usually in the form of mydomain.com. Here, .com is the top level domain. Where as mydomain is the sub domain or subdivision. A host name is a domain name that has one or more IP addresses associated with it.

ipconfig