SNMP Lab

CT320: Network and Systems Administration

Description

For this lab, we will execute SNMP commands with several different options. You will create a document with answers to the questions that follow. Number each question part.question, e.g., 4.3 for Part 4, Question 3. Show it to the TA when you’re done.                 

Hosts

Here are the hosts that we will use. They are not workstations or laptops, but they are devices on the net:                 

Host	Community String
10.1.44.62	public tuba, HP printer, CSB 120
10.1.44.66	public guitar, HP printer, CSB 3rd floor
10.1.44.63	public copier-1, Xerox copier/printer/scanner
129.82.44.10	this4now some kind of switch

They all speak both version 1 and version 2c of the SNMP protocol.                 

Part 1 — SNMP Package Installation

Ensure that the following packages are installed:

• snmp
• snmp-mibs-downloader

See the Installation lab if you’ve forgotten how to install packages.                 

Ensure that the line “mibs :” in /etc/snmp/snmp.conf is commented out.                 

Part 2 — Using snmpget

Use snmpget to retrieve some information about 10.1.44.62:                 

    snmpget -v2c -c public 10.1.44.62 sysDescr.0
    snmpget -v2c -c public 10.1.44.62 sysUpTimeInstance

That’s correct: sysDescr.0 ends with .0, but sysUpTimeInstance doesn’t.                 

Execute the second command several times; note that the time increases.                 

1. What does -v2c mean?
2. What does -c public mean?
3. What is the system description?
4. How long has 10.1.44.62 been up?

Part 3 — Identification

Using snmpget, identify all four hosts. What sort of device is each one? Write it down.                 

Part 4 — Using snmpwalk

The snmpwalk command retrieves a bunch of information:                 

    snmpwalk -v2c -c public 10.1.44.63

It’s quite a lot—send it to a file, and view the file in an editor.                 

1. What is the system description?
2. Who is the system contact?
3. How many network interfaces are there?
   (Look at the lines starting with IF-MIB:: for network interface information.)
4. What are the interface types?
5. What is the MTU of each interface?
6. What is the physical address (alias MAC address) of the Ethernet interface?

Part 5 — Using snmpset

Use snmpget to retrieve just the contact information for 10.1.44.63:                 

    snmpget -v2c -c public 10.1.44.63 sysContact.0

Now, use snmpset to change that contact information:                 

    snmpset -v2c -c public 10.1.44.63 sysContact.0 string "The Dread Pirate Roberts"

1. How did that work out?
2. Why?

Part 6 — Printer MIB

We will now focus on one particular MIB, the Printer MIB.                 

Execute this command, which will display all the information defined in the Printer MIB, which is in /var/lib/snmp/mibs/ietf/Printer-MIB.                 

    snmpwalk -mPrinter-MIB -v1 -c public 10.1.44.66 printmib

Send it to a file; view it in an editor.                 

1. Why did we specify -mPrinter-MIB?
2. Find the capacity of the paper trays, by looking in the output for prtInputMaxCapacity. There are two values, one for each paper tray. What are the values?
3. Find prtInputCapacityUnit in the output, which is the units used for prtInputMaxCapacity. That is, it says whether prtInputMaxCapacity is in sheets of paper, inches of paper, meters of paper, etc. Which one is it?
4. See prtInputCurrentLevel, which is how much paper is actually in the tray right now. What are the values?
5. Read the prtInputCurrentLevel entry in the MIB. What do the values from the previous question really mean?

Part 7 — Color Printers

1. For each printer, fetch the values for prtMarkerColorantValue using snmpwalk. Which printers can print what colors?
   • Curiously, the colors may show as hexadecimal bytes instead of printable ASCII characters. Use this ASCII table to translate.
2. Do the same for non-printers. What happens?

Part 8 — Cleanup

1. Remove the SNMP tools:

    sudo apt purge snmp snmp-mibs-downloader

Part 9 — Credit

Show your work to the TA for credit.