Network Administration

1. Network Administration • Procedures • Tools • Ping • SNMP • Ethereal • Graphs • http://www.pcworld.com/news/article/0,aid,113175,00.asp • 10 commandments for PC security

2. Procedures • Failure detection • Network card locally or at the switch/router • Host monitoring • Traffic monitoring • Route flapping • Intrusion

3. Management Levels • Performance management • Utilization and throughput • Fault Management • What is broken • Configuration management • Track connections • Accounting management • Logging resource use • Security management

4. Infrastructure • Managing entity • Human, network manager at the NOC • Managed device • Switch, router, interface • Management Information Base • Network management agent • Network management protocol (SNMP)

5. Monitoring Protocol • http://www.snmp.org • Network Management Objects • MIB object • Data Definition language • Structure of Management Information (SMI) • Protocol (SNMP) • Security and Administration capabilities • Remote control

6. SMI constructs • Data types • INTEGER -231 to 231-1 • Integer32 -231 to 231-1 • Unsigned32 unsigned version of above • OCTET String 16 bit binary or text data • OBJECT IDENTIFIER MIB information • IPaddress 32 bit internet address • Counter32 32 bit counter, wrap around • Counter64 64 bit counter, wrap around • Gauge32 non wrapping counter • TimeTicks 1/100ths of a second since an event • Opaque string

7. MIB Information • Object Identifier tree

8. MIB information • Organizes protocol information (RFC 2578,2579,2580) • Sorta like the dewey decimal system for network monitoring. • Identification strings: • sysDescr • sysObjectID • sysUpTime • sysContact • sysName • sysLocation • sysServices

9. Protocol Data Unit (PDU) • Data string for SNMP information

10. SNMP Security • Read Community • Read data information from the remote system • Write Community • Write data to the remote system • Trap Community • Receive alarm information from the remote system.

11. SNMP Security • Encryption • SNMP transfers may be encrypted • Authentication • Hashed function secret keys • Playback protection • A hacker can’t hijack the PDU strings • Access Control • Remote host can limit SNMP access to certain objects

12. Tools at USU • http://statler.usu.edu • http://floyd.usu.edu • http://pomoxis.usu.edu • Interpreting the data

13. Windows Administration • User Accounts • Group Accounts • UPS • Fault Tolerance • Backups

14. System Administration • Users • Files, Rights, Groups • System • Security • Virus Protection • UPS • Fault Tolerance

15. System Admin • Virus Protection • Scans incoming data for viruses • Scans the disk for trojans or backdoors • Must be updated regularly, all versions do this automatically if set up. • Beware of back door access to the server • Viruses may not slow down the server • Viruses may propagate via users address books

16. UPS • Handles short duration power failures • Can alert the operator of power failure • Decide how long the UPS needs to power the system • Does the server display need to be on? • How much power does the server need? • Does the UPS have an RS232 control port? • Life of the UPS battery(ies)

17. Server Admin • Fault Tolerance • Multiple power supplies • Multiple CPU’s • Fault Tolerant Disk systems • RAID 0 (disk striping) • RAID 1 (disk mirroring) • RAID 5 (disk striping with parity) • BACKUP

18. Server Fault Tolerance • Dual Power supplies • Power supplies always fail first! • If one supply fails the other can take over • Dual CPU’s • Speed performance • The system can operate with only 1 CPU operating

19. RAID! • RAID 0 • Disk Striping • No fault tolerance • RAID 1 • Disk Mirroring • High Disk Overhead (2-2GB disks=2GB) • High Write overhead (write to both disks)

20. MORE RAID! • RAID 5 • disk striping • parity blocks • Requires at least 3 disk drives • Can improve disk performance • lose and replace 1 disk drive and no data is lost • overhead is 1/N n=number of disks, 5 10GB disks = 40 GB storage

21. Again Backups? • Even a fault tolerant disk system can fail • Always back up • Always have several copies of backups in case one is unreadable • Check the backups to see if they are readable • Store the tapes or removable media in a safe place

22. Server Admin • Watch Event Logs for errors • Log files grow rapidly, delete old logs • Audit Disk usage and resources • Decide when an upgrade is needed

23. Server Admin • Monitoring (Task Manager) • Resources: • Processor • Memory • Disk • Network • Baseline • To determine what is different week to week

24. Server Administration • Network • File Sharing • Printing • Mail

25. File Sharing • Howto • Set up networking, allow sharing • Who will access the files? • Do they need write access? • Is it secure? • Beware of instant messaging

26. Printing • Local or remote • Shared from PC or networked printer • What about security? • Gotchas

27. Mail • Exchange (Microsoft) • POP Mail (Post Office Protocol) • Downloads messages to the client • IMAP Mail (Internet Message Access Protocol) • Downloads headers (subject) to the client • Better Security • SMTP (Simple Mail Transfer Protocol) • Sends messages from the client to the Internet • Calendaring (collaboration)

28. Mail • Disk space • SPAMMING • Relaying

29. Network Administration