Why a Computer Network??? Stand alone Computer. For What?

Transcription

1 Computer Network Josua M Sinambela, CCNP, CCNA, CEH, CompTIA Security+ Computer Network & Security Consultant RootBrain IT Training & Consulting josh@rootbrain.com Website: 1

2 Why a Computer Network??? Stand alone Computer. For What? IT Training & Consulting 2

3 Distribute computation among nodes Coordination between processes running on different nodes Remote I/O Devices Remote Data/File Access Personal communications ( , chat, A/V) World Wide Web... and many other uses IT Training & Consulting 3

4 Many types of connection media : telephone lines, optical fibers, cables, radios, etc. Many different types of machines and operating systems Many different network applications need for a STANDARD in communication technology: O S I IT Training & Consulting 4

5 Something interesting from Computer Network??? Easiness No distance Mobility Efficient IT Training & Consulting 5

6 Network Administrator, Advantages Good salary Control other peoples Faster than others Relax Disadvantages ERROR, then people want to kill YOU!!! Indonesian Salary Guide 2008/ IT Training & Consulting 6

7 Study Basic network theory OSI Layer Network devices Routing Network security Programming IT Training & Consulting 7

8 Study Network Skill Operating system Server Client Router, Switch, Cabling, etc (network devices) Network Technology Hacking not Cracking Certification Real Experience Time can answer??? IT Training & Consulting 8

9 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 IT Training & Consulting 9

10 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 IT Training & Consulting 10

11 OSI Model Layers Transport Layer Provides reliable delivery Performs error detection Includes end to end connection Network Layer Provides logical addressing Routing layer IT Training & Consulting 11

12 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 IT Training & Consulting 12

13 Keys Layers of the OSI Model IT Training & Consulting 13

14 OSI Model and Protocols IT Training & Consulting 14

15 Network Devices Wired Wireless IT Training & Consulting 15

16 Router, Switch, Hub, Modem, IT Training & Consulting 16

17 TCP/IP IT Training & Consulting 17

18 TCP/IP IT Training & Consulting 18

19 Operating Systems IT Training & Consulting 19

20 IT Training & Consulting 20

21 Network Security Network Security Firewall IT Training & Consulting 21

22 Hacking NOT cracking IT Training & Consulting 22

23 Programming #include <string.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <sys/wait.h> #include <signal.h> #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,size of(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); IT Training & Consulting 23

24 Server - Client IT Training & Consulting 24

25 Certificate IT Training & Consulting 25

26 Selesai.. Thanks IT Training & Consulting 26