1. Network Hosts Analyzer Hadas Shumovitch shumoviz@t2 Elad Levi seladlvy@t2 Tal Katz sdew@t2

2. Presentation Layout  Background  Program outline  Cache refresh algorithm  User Interface  Points for Extension

3. Background  The Computer Science faculty has hundreds of computers and users.  There is a need for a program to monitor and supervise all of the computers.  There are programs available, but they are very expensive.

4. Background - continued  Our goal is to design a scalable, configurable monitoring system which answers the faculty needs and is easy to use.

5. Program outline  The program handles two threads.  One thread is responsible for interaction with the user, while the other is responsible for updating the system’s cache.

6. Program outline  In order to reduce the amount of communication through the faculty network, and reduce the program response time, we’ll maintain a cache.  The cache keeps the information about the faculty computers and floors switches.  The updating frequency of the cache is defined by the user.  Information requests from the user are answered by retrieving the information from the cache, except for “who is logged in right now”.

7. Cache refresh algorithm  Cache updating frequency can be changed by the user to any whole number of minutes. The program is loaded with a default updating frequency of one hour.  In addition, it is possible to perform immediate cache refresh.

8. Cache refresh algorithm for (every floor) { get floor’s router ARP table; for (every switch in the floor) { get switch's data; for (every MAC address connected to the switch) { convert MAC -> IP address; get end station local data; // UDP connection update the relevant entry in the cache; }}}

9. Example  Router Switch End Stations  Floor 7:  Floor 3:

10. Algorithms – Additional communication modules A telnet API:  The routers and switches in the faculty run Command Line Interface (CLI), through which we get their inner information.  In order to connect to the routers and switches we have implemented a Telnet API.  The implementation is especially suitable for the kind of routers and switches in the faculty.

11. Algorithms – Additional communication modules End Station Agent:  Every end station in the faculty, including Laptops, should run an agent.  When the agent starts to run, it reads from a configuration file the computer’s data.  The agent will listen for data requests on a pre defined port which is known by the analyzer main system.

12. Algorithms – Additional communication modules End Station Agent - continued:  The agent is single threaded.  We have implemented two versions of the agent. One for Unix, and one for Windows 2000 and up.

13. User Interface No GUI mode:

14. GUI mode Main Menu:

15. User Interface Switches Menu:

16. User Interface Ports Menu:

17. User Interface End Stations Menu:

18. User Interface End Station:

19. Points for Extension  Working from two different computers.  End station agent informing on inner problems.