1. Computer Network Sritrusta Sukaridhoto

2. Why Computer Network ??? Stand alone Computer …. FOR WHAT ???

3. Something interesting from Computer Network ??? Easiness No distance Mobility Efficient

4. Network Administrator,… Advantages  Good salary  Control other peoples  Faster than others  Relax Disadvantages  ERROR, then people want to kill YOU !!!

5. Study… Basic network theory  OSI Layer  Network devices  Routing  Network security  Programming

6. Study… Network Skill  Operating system  Server – Client  Router, Switch, Cabling, etc (network devices)  Hacking not Cracking  Certificate Experience  Time can answer ???

7. Open System Interconnection (OSI) A model defines the stages or tasks of a protocol as it prepares to send data  Open meaning standards available to all. The model is devided into seven distinct layers Each subsequent layer should perform a well- defined function and the layer boundaries are designed to minimize the information flow across the interfaces

8. OSI Model Layers Application Layer  Provides a user interface (examples: HTTP, SMTP)  Includes file, print, database, app. Services Presentation Layer  Presents the data (example: JPEG)  Includes encryption, compression and translation services Session Layer  Keeps different applications data separate

9. OSI Model Layers Transport Layer  Provides reliable delivery  Performs error detection  Includes end to end connection Network Layer  Provides logical addressing  Routing layer

10. OSI Model Layers Data Link Layer  Combines packets into bytes then into frames  Performs error detection (not correction)  Provides Media access addressing (point-to- point)  Media Access Control and Data Link Control Physical Layer  Moves bits between devices

11. Keys Layers of the OSI Model

12. OSI Model and Protocols

13. Network Devices Wired Wireless

14. Router, Switch, Hub, Modem, …

15. TCP/IP

17. Operating Systems

19. Network Security Firewall

20. Hacking NOT cracking

21. Programming /* ** server.c -- a stream socket server demo */ #include #define MYPORT 3490 // the port users will be connecting to #define BACKLOG 10 // how many pending connections queue will hold void sigchld_handler(int s) { while(wait(NULL) > 0); } int main(void) { int sockfd, new_fd; // listen on sock_fd, new connection on new_fd struct sockaddr_in my_addr; // my address information struct sockaddr_in their_addr; // connector's address information int sin_size; struct sigaction sa; int yes=1; if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) { perror("socket"); exit(1); } if (setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(int)) == -1) { perror("setsockopt"); exit(1); } my_addr.sin_family = AF_INET; // host byte order my_addr.sin_port = htons(MYPORT); // short, network byte order my_addr.sin_addr.s_addr = INADDR_ANY; // automatically fill with my IP memset(&(my_addr.sin_zero), '\0', 8); // zero the rest of the struct if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1) { perror("bind"); exit(1); } if (listen(sockfd, BACKLOG) == -1) { perror("listen"); exit(1); } sa.sa_handler = sigchld_handler; // reap all dead processes sigemptyset(&sa.sa_mask); sa.sa_flags = SA_RESTART; if (sigaction(SIGCHLD, &sa, NULL) == -1) { perror("sigaction"); exit(1); } while(1) { // main accept() loop sin_size = sizeof(struct sockaddr_in); if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size)) == -1) { perror("accept"); continue; } printf("server: got connection from %s\n", inet_ntoa(their_addr.sin_addr)); if (!fork()) { // this is the child process close(sockfd); // child doesn't need the listener if (send(new_fd, "Hello, world!\n", 14, 0) == -1) perror("send"); close(new_fd); exit(0); } close(new_fd); // parent doesn't need this } return 0; }

22. Server - Client

23. Certificate

24. EEPIS Computer Network Lab Jaringan Komputer  Ka. Lab: Sritrusta Sukaridhoto  Gedung D4 lt. 3 UPT Jaringan Komputer  Ka. UPT: Nonot H  Network Admin: Sukaridhoto, Amang  Webmaster: Udinharun  Gedung IT lt. 2

25. Thank You…