ENS lab SNMP

Enterprise Network Systems

Laboratory Work - Simple Network Management Protocol (SNMP)
Assessment Value 0%

Introduction
SNMP Versions and Definitive Documents
Method
Writeup of the lab

Introduction

The object of today's laboratory work is to examine the operation of Simple Network Management Protocol (SNMP). The function of SNMP is to gather information from networked devices for the purpose of network management.

Follow the instructions below and use a pen and paper or wordprocessor to keep a record of your responses to the questions.

This work will be assessed informally during the lab period.

SNMP Versions and Definitive Documents

SNMP is defined by IETF (http://www.ietf.org ) through a group of RFCs shown below.

Reference:

rfc1155 : Structure and Identification of Management Information for TCP/IP based internets
rfc1156 : Management Information Base Network
rfc1157 : A Simple Network Management Protocol
rfc1441 : Introduction to SNMP v2
rfc2579 : Textual Conventions for SNMP v2
rfc2580 : Conformance Statements for SNMP v2
rfc2578 : Structure of Management Information for SNMP v2
rfc3416 : Protocol Operations for SNMP v2
rfc3417 : Transport Mappings for SNMP v2
rfc3418 : Management Information Base for SNMP v2
rfc3410 : Introduction and Applicability Statements for Internet Standard Management Framework
rfc3411 : Architecture for Describing SNMP Frameworks
rfc3412 : Message Processing and Dispatching for the SNMP
rfc3413 : SNMP Applications
rfc3414 : User-based Security Model (USM) for SNMP v3
rfc3415 : View-based Access Control Model for the SNMP
rfc3584 : Coexistence between SNMP v1, v2 and v3

Method
Open the Packet Tracer file using version 5.2 or above.

The medway-ME router is configured to serve an SNMP community medway-public for read-only access, and medway-private for read-write access.
Using SNMP it is possible to retrieve and set various configuration options.

Test SNMP Requests from medway-ME router

1. Start the MIB browser from the desktop on MIB_Browser PC. Click the Advanced button and use the following details:
     Address: 10.0.0.1
     Port: 161
     Read Community: medway-public
     Write Community: medway-private
     SNMP Version: v3

Select OK

2. Suppose we wanted to view the IOS version on the medway-ME router, we need to select this parameter from the MIB options.

Expand the MIB tree on the left side of the application to select the node with the name:

MIB Tree.router_std MIBs.iso.org.dod.internet.mgmt.mib-2.system.sysDescr

Make a note of the OID value.

3. Ensure that Get is selected in the Operations field of the MIB browser. Press the GO button to retrieve the value from the device.

Which version of IOS is running? Verify this directly on the router via the CLI - type show version at the priv exec prompt.

4. Now select the node with the name:

MIB Tree.router_std MIBs.iso.org.dod.internet.mgmt.mib-2.system.sysUpTime

Make a note of the OID value.

5. Ensure that Get is selected in the Operations field of the MIB browser. Press the GO button to retrieve the value from the device.

How long has the router been 'up'?

6. Now get the value of .sysName node.

What is its value? Make a note of the OID value.

Compare the OID values. What is their purpose?

Setting Variables

Some variables can be set from the management station. these have an Access value of read-write.

When a piece of managed hardware is installed onto a network, it may be necessary to add some information pertaining to your organization.

7. Select the .sysContact node and change the operation to Set.

Select the OctetString data option and enter your name.

Press GO.

8. Change the operation back to Get and press GO again to verify that the data was set correctly.

9. Set the .sysLocation node value to ME4 4TB and verify that it has been set correctly.

Using Get Bulk

The Get Bulk command can be used to request seversl parameters at once instead of requesting them singly.

10. Expand the MIB tree on the left side of the application to select the node with the name:

MIB Tree.router_std MIBs.iso.org.dod.internet.mgmt.mib-2.interfaces

Ensure that Get Bulk is selected in the Operations field of the MIB browser. Press the GO button to retrieve the values from the device.

Note that now you have received all of the data held under the interfaces branch of the MIB tree.

How many interfaces are there? Which of the three interfaces is administratively down?

Accessing other devices

Now click the Advanced button and use the following details:
     Address: 10.2.0.1
     Port: 161
     Read Community: medway-public
     Write Community: medway-private
     SNMP Version: v3

Select OK

You can now access the nelson-south router.

11. Access the .sysLocation node and give this an appropriate value. Remember to use the OctetString for the Type.

12. Access the .sysContact node and give this an appropriate value. Remember to use the OctetString for the Type.

13. How many interfaces does this router have in its MIB table under Tree.router_std MIBs.iso.org.dod.internet.mgmt.mib-2.interfaces

Check the exchange of PDUs via the Simulation tab on Packet Tracer. View the contents of a request PDU and a Response PDU.

How do they differ?

Optional Further Work

Add a layer 2 switch to your network. Enable SNMP via the CLI. Compare the interface information with that of one of the routers.

Writeup of the lab

You are expected to write an account of the work that you carried out in the lab. Show CLEARLY the answers that you have found and include printouts where necessary.

Make sure that it is easy to find the answers to the questions.

You should be sure to answer all questions that were posed and when you are finished be able to write a short explanation of the process that takes place when a management station requests details from a managed device.

Keep a record of this work in your log book. Show it to your lab demonstrator before you leave.

http://www.javvin.com/protocolSNMP.html