CMPE 151: Network Administration

1. CMPE 151: Network Administration Spring 2004

2. Class Description • Focus: system and network administration. • Sequence of exercises. • E.g., installing/configuring client machines (including kernel), servers (FTP, Web, file server, mail, DNS, etc.), network gateways (firewalls, NAT), etc. • Final project.

3. Class Format • Lectures. • Meet in BE 168. • Typically, 2 lectures on each topic: • A more “theoretical” lecture on background material. • A more “practical” lecture to get projects started. • Lab time. • Students expected to spend ~10 hr/week in the lab.

4. More class information • Grading: • Weekly projects: 75%. • Final project: 25%. • Academic Integrity Policies: • Will be strictly enforced. • Come talk to us if questions.

5. Class Web Page • www.cse.ucsc.edu/classes/cmpe151/Spring04. • One of the main course resources. • It will be constantly updated. • Students are responsible for keeping track of updates (e.g., syllabus, project due dates, links to project descriptions, etc.).

6. Projects • Current list and due dates on Web page. • Project description. • Should have all information required for each project, • Including how to submit project. • They will be added as we go.

7. Readings and Documentation • List of recommended books on the Web page. • Links to on-line documentation. • Documentation provided on the Web page as starting point. • Seeking further documentation to complete an assignment is considered part of the assignment.

8. Lab Usage Policies • Very important! • This is our lab and we must keep it in working condition!

9. Lab Usage Policies (cont’d) • Access: • Only to registered students! • No food or drinks! • Equipment: • All equipment must remain in the lab at all times. • Students are responsible ($$$) for faulty, stolen, vandalized equipment. • Students must report immediately any problems. • Lab Fee: • Used for printing and some “non-permanent”equipment.

10. Lab Setup • LAN of workstations. • Connected to outside world through netlab.cse.ucsc.edu. • All students will get an account on netlab.cse.ucsc.edu. • Students will have root access on all other machines. • After finished using a machine for the day, students must restore them to their original state.

11. UNIX Basics

12. Brief history • Originally developed at AT&T Labs in the late 60’s. • In the mid 70’s, UNIX was made available to universities and research centers free of charge. • In 1977, Berkeley’s UNIX distribution became available: BSD (Berkeley Software Distribution). • Final release: 4.4BSD-Lite. • FreeBSD originates from this release.

13. UNIX structure Utilities: editors, compilers, etc. Shell UNIX Kernel Hardware

14. Shell • Command interpreter. • Interface between user and OS. • Several shells: bourne shell, C shell, bash, etc.

15. File structure • Unix file systems are organized as hierarchies of files and directories.

16. File structure: example Server 2 /root Server 1 /root Client /root nfs export usr vmunix users staff users students ann eve joe bob

17. Files and directories • Files are leaf nodes in the file structure tree and directories are intermediate nodes. • File names: up to 255 characters. • Upper and lower case letters. • Numbers. • Some special characters. • File name extensions (preceded by “.”). • Describes file content.

18. Pathname • Concatenation of directory names from root to file name using “/” as delimiters. • Example: /export/users/bob • /cse/faculty/katia • Absolute versus relative pathnames.

19. Special directories • Working directory (or “current” directory): “.” • Home directory (“~”). • Parent directory: “..”

20. Navigating… • pwd. • cd. • ls.

21. Creating and removing directories • mkdir. • rmdir.

22. Moving and copying • mv. • cp. • Example: $ pwd /home/katia $ mv summary.txt documents/.

23. Access permissions • Types of permissions: • Read, write, execute. • Who can do it? • Owner, member of owner’s group, anyone else. • ls –l (long) displays access permissions, file owner and group, size, last modified data and time, file name.

24. Changing access permissions • chmod • Example: chmod a+rw summary.txt

25. Listing file contents • More, cat, less.

26. Shell • Command interpreter. • Command line. • Shell script.

27. Command line • Syntax • <command> arg1 arg2 … argn [cr] • Execution: • If shell finds file with same name as command, a new process is started to execute that file. • Shell is sleeping while command executes. • Shell returns to active and issues prompt.

28. Standard input and output • Default places where input info is read and output info is sent. • By default, stdio and stdout is the terminal.

29. Redirection • Redirect stdin and stdout. • <command> [arguments] > filename • <command> [arguments] < filename • Example: • $ cat summary.txt • $ cat summary.txt > summary2.txt • $ cat > sample.txt

30. Pipes • stdout of one command “piped” to stdin of anther command. • Example: • cat summary.txt | more • who | grep “katia”

31. Running program on background • OS runs program while you can do other things. • “&”.