Computer Network Manual

Socket Programming for TCP in Python Sockets and the socket API are used to send messages across a network. They provide a form of interprocess communication (IPC). The network can be logical, a local network to the computer or physically connected to an external network, with its own connection to the other networks. The obvious example is the internet. Sockets have a long history. Their use originated with ARPANET in 1971 & later become an API in the Berkley Software Distribution (BSD) operating system released in 1983 called Berkely sockets. The most common type of socket applications is client-server applications where one side acts as the server & waits for the connections from the clients. TCP Sockets: We will create a socket object using socket .socket() and specify the socket type as socket.SOCK_STREAM. When we do that the default protocol that used is the transmission control protocol (TCP).

Socket Programming using UDP in Python What is Socket Programming? Socket programming is a way of connecting two nodes a network to communicate with each other. One socket (mode) listens on a particular port an IP, while other socket reaches out to the other to form a connection, server forms the listens to socket while client reaches out to the server. UDP: UDP or user datagram protocol is connectionless protocol/ which is suitable for applications that require efficient communication that doesn't have to carry about packet loss. For gaming applications, this tends to the perfect protocol due to the lower overhead in current as opposed to TCP. Steps to implement UDP using Socket programming: import socket library create a socket object reserve a port on computer and bind to port. put the socket into listening mode. establish a connection with the client. start server (after importing and creating socket ) open the terminal and connect to the server with t

Configuring Static NAT in Cisco Packet Tracer NAT: There are several situations where we need address translation such as a network which don't have sufficient public IP addresses want to connect with the internet , two networks which have save IP addresses want to merge or due to security reason a network want to hide its internal IP structure from the external world. NAT is the process which translates IP addresses. NAT can be performed at firewall , server and router. Our network is built with private IP addresses and we want to connect it with the internet .As we know to connect with internet we require public IP addresses. In this situation we can use NAT which will map private IP with public IP. Two networks which are using same IP addresses scheme want two merge. In this situation NAT device is used to avoid overlapping issue. We want to connect multiple  computers with internet through the single public IP addresses.In this situation NAT is used to map the mult

IMPLEMENTATION OF DHCP IN CISCO PACKET TRACER: What is DHCP? Dynamic Host Configuration Protocol (DHCP) is a networking management protocol used to dynamically assign an IP address to any new node or device entering the network. DHCP permits a node to be configured automatically, thereby avoiding the necessity to involvement by a network administrator. DHCP can be implemented on small local networks as well as large enterprises  networks.DHCP  runs at the application layer of the transmission control protocol/IP (TCP/IP) protocol stack to dynamically assign IP addresses to connected  devices.It  is a client-server protocol in which server manage a pool of unique IP addresses, as well as information about client configuration parameters, and assign addresses out of those address pools. How to IMPLEMENT DHCP : - 1)  Select  PCs ,  Routers and  Switches.  2)  Make all the necessary connections.  3)  Assign IP addresses , subnets and gateways. COMMANDS:  ROUTE

Configuring Open Shortest Path First Protocol: What is OSPF? The OSPF (Open Shortest Path First) protocol is one of a family of IP Routing protocols, and is an Interior Gateway Protocol (IGP) for the Internet, used to distribute IP routing information throughout a single Autonomous System (AS) in an IP network. The OSPF protocol is a link-state routing protocol, which means that the routers exchange topology information with their nearest neighbours. The topology information is flooded throughout the AS so that every router within the AS has a complete picture of the topology of the AS. This picture is then used to calculate end-to-end paths through the AS, normally using a variant of the Dijkstra algorithm. Therefore, in a link-state routing protocol, the next hop address to which data is forwarded is determined by choosing the best end-to-end path to the eventual destination. CONFIGURATION: STEPS: 1)  Select  3PCs  and connect them with  Routers  and Switches . T hen