The Utterances of a Peculiar Mindset

After my blog entry about Networking, I got a mail asking what exactly is DHCP and TCP/IP.
Here is the answer.

DHCP
Every computer system on a TCP/IP network is assigned a unique address known as IP address to identify a computer on the network. As the network grows, the network administrator has to keep track of the addresses given to the systems. This becomes even more complex when systems are added or removed from the network. Hence, DHCP is used to dynamically assign IP addresses to computers on a network. Instead of the network administrator, a DHCP server keeps track of the IP addresses assigned. Hence, a system joining a network is assigned an IP address from an IP pool. That IP address is retrieved back to the pool when the system is removed. The IP address assigned to a system changes every time it boots up and gets connected to the network.

http://www.dhcp.org

TCP/IP

TCP/IP stands for Transmission Control Protocol / Internet Protocol. It is the basic set of rules that is used in almost all networks present today. It has a two layer structure in which TCP forms the higher layer and IP forms the lower layer of the protocol. TCP handles the transmission of packets over the network and it makes sure that the original packet is reassembled properly at the destination node. The lower layer, Internet protocol, is closer to the actual network it handles the address part of the packet. This layer checks whether the packet reaches the right destination. TCP/IP communication is primarily point to point, which means that each communication is from one point or node in the network to another point or node. It uses a client/server model of communication. The address given to each node on a TCP/IP network is called an IP address. This address can be given manually to a system, or a network can be configured to give an IP address to a machine when it logs on to the network. When an IP is given manually it is called static IP allocation, and the second method is called dynamic IP allocation. For this a technique known as DHCP or Dynamic Host Configuration Protocol is used. This method of IP allocation is normally used when your system gets connected to the internet using a dial up modem. A DHCP server used by your ISP assigns an IP to your system dynamically. The address scheme that is presently used is called IPv4. In this method each system is given a unique number separated by four dots. An example is 162.122.111.67. Here each number separated by dots can take a value between 0 and 255. These numbers specify the node address, network address, IP class, etc. of a node on a network. In the future, a new addressing scheme known as IPv6 would be used to overcome some of the limitations of IPv4.

In our NL (Networking Laboratory) oral, some of us were asked to type command “ipconfig /all” at command prompt and explain the things visible in the output of the command.
The information displayed on the screen is described below.

Adapter address

This is a hexadecimal address, also called the MAC address, unique to every network adapter. It is hard coded into the card by the manufacturer, and consists of six 8-bit numbers. However remember that modems do not have this address-this is restricted to network adapters-the number for a modem or dial up adapter is set to a meaningless default number.

This is the current IP networking address. Depending on whether the DHCP is used, this may be static or dynamically allotted. The static value is entered in the TCP/IP network configuration menu.

This is used to mask a portion of the IP address, to determine the subnet where the computer is located-within the internal network. All computers running TCP/IP must have the subnet mask defined.

This is the IP address of the computer that provides the connection to a remote network. The gateway computer is the computer that TCP/IP will use to communicate and route data destined for computers on remote networks.

This entry indicates the IP address of the DHCP server. The DHCP server, when present, will dynamically assign an IP address to the machine upon connecting to the network. Clicking on the Release button will release the IP address, and the Renew button requests a new IP address from the DHCP server.

These settings specify the IP address of the Primary and Secondary WINS Server, if present. The WINS servers translate the NetBIOS names into the corresponding IP addresses.

These values show when the current IP address was obtained and when it is due to expire. You can use the Release and Renew buttons to release and renew your current IP address. In any case, the DHCP client automatically attempts to renew the lease, when 50 per cent of the lease time has expired.

Hello friends
These days I was li’l busy with practical exams.
All three pracs are over now.
Now preparing for Theory exams starting from 24th.
So guys, you can wish me all the best….