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Showing posts from August, 2015

DHCP & DNS

                What is DHCP and DNS ?? DHCP: Dynamic Host Control Protocol It's a protocol used to assign IP addresses dynamically instead of assigning static ip's to each. The process involves a process called DORA process. D - Discover O - Offer R - Request A - Acknowledgement D - Discover: Host (PC, printer, laptop, Access systems..etc, IOT) sends a UDP broadcast to the server. Packet from Host --> server O - Offer: The server offers a Unique IP address to the host in response to the Broadcast. Packet from server --> Host R - Request: The host requests for the IP address offered by the server. Packet from Host --> server A - Acknowledgement: The server sends a acknowledgement packet along with details of IP address, Subnet mask, gateway, Dns server1 and Dns server 2. Packet from Server --> Host DNS: Domain Name Server. As we humans are uniquely identified by our names, Every website is uniquely accessed by it's domain a

How to calculate Subnets

            CALCULATING NETWORK ID ON FINGERTIPS This is a very simple technique which you will never find in any other sites or books, While attempting any exams we are asked to Calculate the Network id of the given IP. It's not a recommended way to use pen, book and calculations to find out the Ans. SO, Here come's a simple Formula to calculate that within seconds. *********************************************************************************************************** *As the General subnets we can do easily, But this process is very useful in calculating subnets such as   192.168.2.181/30      * *  ==> The network ID of the subnet is 192.168.2.180 we can calculate that in less than 7 seconds with this method                  * *********************************************************************************************************** Follow the steps below: 1) Identify the CIDR value (number of network bits). 2) Identify the near by Round of value for tha