SNMP Operations

• SNMP GET

• SNMP GETNEXT

• SNMP GETBULK

• SNMP SET

MibBrowser allows the user to perform the typical SNMP operations. The operations are categorized as:

• Retrieving Data - GET, GETNEXT, GETBULK

• Altering Variables - SET

• Receiving Unsolicited Messages - Traps

To perform any basic operation as categorized above, it is essential to specify the Object ID, the instance, host name, and the community string. Changes can also be made to the parameters in the MibBrowser Settings dialog box. To get a vivid outlook on the MibBrowser settings, refer the Configuration topic.

Specifying the Index

To specify an object to an SNMP agent, both the Object ID (which defines the type of object) and the instance (the specific object of the given type) need to be provided. From the MIB you can get the Object ID, to which an instance needs to be added to completely identify the object of interest.

For non-tabular or scalar objects, the instance is 0. For example sysDescr is a scalar object under the system group in RFC1213-MIB and it should be specified as sysDescr.0 in Object ID field of MibBrowser. In MibBrowser, this need not be specified if the MIB is loaded. i.e. RFC1213-MIB. MibBrowser adds it to the selected node while performing the GET operation.

For tabular objects, the instance is defined in the MIB as index, and it is a sequence of one or more objects. For example, ifInOctets of ifTable defined in RFC1213-mib, the index is ifIndex (INTEGER) and may be specified as ifInOctets.1 provided that there exists a row with index 1 in the querying agent.

Another example tcpConnState of tcpConnTable under tcp group of RFC1213-MIB. The indexes of the tcpConnTable are tcpConnLocalAddress (IpAddress), tcpConnLocalPort (INTEGER), tcpConnRemAddress (IpAddress) , tcpConnRemPort (INTEGER) and may be specified as tcpConnState.179.74.15.126.1192.225.226.126.197.80 provided that there exists a row with Index 179.74.15.126.1192.225.226.126.197.80 in the querying agent where

• 179.74.15.126 represents the value of the first index tcpConnLocalAddress (IpAddress),

• 1192 represents the value of the second index tcpConnLocalPort (INTEGER),

• 225.226.126.197 represents the value of the third index tcpConnRemAddress (IpAddress)

• 80 represents the value of the fourth index tcpConnRemPort (INTEGER).

To get the information about the MIB Node in the MIB Tree, click the Description icon or choose View -->Description menu item or use a shortcut of Alt + R. This gives a list of all the vital characteristics of the node such as the Node, OID, Path, MibModule, Syntax, Status, etc.