How to Configure SNMP on Cisco Devices (Routers, Switches)

Simple Network Management Protocol (SNMP), so “simple” yet so powerful.  SNMP delivers a standardized framework that can be used for the monitoring and management of network devices.

SNMP is one of the most powerful tools that can be used by today’s network administrators and engineers. 

SNMP allows admins to poll for data such as CPU usage, memory usage, bandwidth usage and many other items. 

SNMP polls network devices for this information using MIBs (Management Information Base).  These MIBs are nothing more than a standardized collection of objects that can be queried for information.

Network monitoring using SNMP can be a huge benefit to any network administrator.  Many applications can be used to collect this SNMP data and produce trending graphs and reports. 

Some of the following well-known applications can be found in and around many networking environments: Cisco Prime, PRTG, Solarwinds NPM, MRTG.

Lets take a closer look at the “simple” configuration of SNMP.

Configuration Tasks:

1. Create standard ACL to permit SNMP server.
2. Configure SNMP Community String for read-only or read-write access, and reference ACL.
3. Configure Optional identification information.
4. Configure SNMP traps to be sent to SNMP Management Server.

Commands:

1.       access-list 10 permit 172.16.5.45 0.0.0.0

Creates a standard access-list that permits host 172.16.5.45.

2.       snmp-server community MON!T0R RO 10

Configures a read-only community string called MON!T0R and uses access-list 10 to state who is allowed to use that community string, in this case only host 172.16.5.45.

Optional:

3.

snmp-server location 1370 NoWhere Ln, NC 28652
snmp-server contact Network Admin | 336-679-3444
snmp-server chassis-id IDF10-AS1

Configures optional SNMP information for device identification.  These identification settings state where the device is located and whom is responsible for the device.

4.       snmp-server enable traps %trap%

Configures SNMP traps to be sent to 172.16.5.45 when events occur.  By using the “?” where the %trap% is located you will be presented with a list of all traps that can be sent.

At this point you have created a basic SNMP community string and provided security by using an ACL to permit access to only devices needed.  Now you should be able to view information that is polled by your SNMP Server.

Below are some examples of the information that can be polled by an SNMP Management Server: