Network Monitoring Assignments

Transcription

1 Network Monitoring Assignments Cyril Soldani INFO th February

2 Outline 1 Introduction 2 Using SNMP Tools 3 Web-based SNMP Browser 4 Agenda 2

3 Network Management and Security Assignments There will be three practical assignments in this course. Network Management 1. Using SNMP Tools 1.1 Retrieving variables manually 1.2 Retrieving variables from a script 2. Developing a web-based SNMP browser 2.1 Detecting SNMP agents in a network 2.2 Retrieve MIB views during browsing Network Security 3. To be announced All info to appear at 3

4 Assignments Infrastructure You will do your assignments in groups of 2. Access to the networking lab To do the assignments, you will need SSH access to our networking lab. You will receive your credentials when you send me your group composition by . Submitting your assignments To submit your work, you will use the RUN submission platform at You will need to register individually if not already done for another course. You will use your lab credentials as group names when constituting groups for the projects. Questions to be asked on scinfo.be? Q&A sessions possible. 4

5 Outline 1 Introduction 2 Using SNMP Tools 3 Web-based SNMP Browser 4 Agenda 5

6 Retrieving Variables Manually Using the Net-SNMP tools installed on a lab machine, you will retrieve various data from a Cisco router. What is the system description (sysdescr)? How many interfaces? What kind of interfaces? Which interfaces are on? What is the MTU? What is the MAC address of Ethernet0/0? Is IP forwarding enabled? What is the default TTL? Try to change the MTU. Does it work? Why? In your (short) report, give both the answers and the commands you used to get them. 6

7 Retrieving Variables from a Script Write a script which runs every 5 minutes, and which writes into a log file the number of packets the router has received and emitted during those 5 minutes (one column for each). Pay attention to potential counter wrapping (discuss it). Once per day, the router sees an increase in traffic. Can you tell when? In your (short) report, plot the resulting file for 24 consecutive hours. 7

8 Outline 1 Introduction 2 Using SNMP Tools 3 Web-based SNMP Browser 4 Agenda 8

9 Web-based SNMP Browser You will develop a web application which allows browsing all SNMP agents in our network lab. Rough UI The user is first presented with a page listing all the detected SNMP agents. When he clicks an agent s link, the site shows the top-level content of the agent s MIB. When he clicks an OID link, that OID should either be expanded, or its value should be shown. You can refine/depart from that UI. It is just a starting point. Discuss the trade-offs (convenience, performance,... ) of your chosen approach. 9

10 Detecting the SNMP Agents To feed the machine list of the site, you will write a program which scans the given network for SNMP agents, and generate that index page. The range to scan and the different SNMP versions and authentication parameters to try will be given in a (simple) configuration file. Your program should use asynchronous requests so that the whole detection takes not much more than 3 SNMP timeouts for a whole /24 network. You will setup a CRON job to run that program every 15 minutes. You can write that program as a POSIX shell, a C program or a Python program. 10

11 MIB Browser The MIB views of the SNMP agents should not be retrieved in advance, but on demand, from a PHP script. There is a PHP binding to Net-SNMP. You can tweak the interface to your linking. By order of importance, criteria are: 1. Correct information 2. Reactive site, no devilishly long pauses 3. Efficient retrieval, avoid retrieving data which is not needed 4. Simplicity of the code 5. Sexiness of the UI You can play with fancy HTML5/CSS3/AJAX if you d like to experiment with it, but only is the rest is working good first. You can cache MIB structure if you like, two hours refresh should be OK (but it would be nice to plan a purge option). 11

12 Outline 1 Introduction 2 Using SNMP Tools 3 Web-based SNMP Browser 4 Agenda 12

13 Agenda 1. Using SNMP Tools: report due on the 2nd of March 2. Developing a Web-based SNMP Browser 2.1 Partial version (detection): (short) report and detection program due on the 16th of March. 2.2 Complete version: complete report, detection program and PHP site due on the 13th of April. 10% penalty by late day No last minute deadline postponing! If needed, ask in advance, but those are already quite late. I ll send feedback (not grades) as soon as possible. 13

14 Q & A? 14