COMPUTER NETWORKS
Reg.no : 22BRS1303
Name : Nisha Dipak gote
Course Code : BCSE308P
Course Title : COMPUTER NETWORKS
LAB Slot : L5+L6
Faculty Name : DR.A.SWAMINATHAN
QUESTION: Using the given components and devices, such as routers, switches and cat6 cables,
create a of any topology. Configure the router and configure the IP for all n nodes connected in the
network using dynamic DHCP. Write a UDP Client Server program to perform a
multiuser chat program.
SERVER CODE:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#define PORT 12345
#define BUFFER_SIZE 1024
int main() {
int sockfd;
struct sockaddr_in server_addr, client_addr;
socklen_t client_len;
char buffer[BUFFER_SIZE];
// Create UDP socket
sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if (sockfd < 0) {
perror("Socket creation failed")
exit(EXIT_FAILURE);
}
// Initialize server address structure
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
server_addr.sin_port = htons(PORT);
// Bind the socket to the server address
if (bind(sockfd, (const struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
perror("Bind failed");
exit(EXIT_FAILURE);
printf("Server started. Waiting for messages...\n");
while (1) {
// Receive message from client
memset(buffer, 0, BUFFER_SIZE);
int recv_len = recvfrom(sockfd, buffer, BUFFER_SIZE, 0, (struct sockaddr *)&client_addr, &client_len);
if (recv_len < 0) {
perror("Error in receiving message");
exit(EXIT_FAILURE);
printf("Received message from %s:%d: %s\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port), buffer);
close(sockfd);
return 0;
CLIENT CODE:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#define PORT 12345
#define BUFFER_SIZE 1024
int main() {
int sockfd;
struct sockaddr_in server_addr;
char buffer[BUFFER_SIZE];
// Create UDP socket
sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if (sockfd < 0) {
perror("Socket creation failed");
exit(EXIT_FAILURE);
// Initialize server address structure
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = inet_addr("192.168.1.1"); // Replace with the server's IP address
server_addr.sin_port = htons(PORT);
while (1) {
// Input message from user
printf("Enter your message: ");
fgets(buffer, BUFFER_SIZE, stdin);
// Send message to server
if (sendto(sockfd, buffer, strlen(buffer), 0, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
perror("Error in sending message");
exit(EXIT_FAILURE);
close(sockfd);
return 0;
}
OUTPUT:
:
