SMI (MIB and PIB) Paths in Wireshark

OID resolution and MIB and PIB parsing are both performed using LibSMI. If the libSMI feature is supported by your version of Wireshark, you can enter one or more paths to the MIB and PIB modules here.

Directory name:

A directory for modules, such as /usr/local/snmp/mibs. The default SMI path for your system is automatically used by Wireshark, so you typically don’t need to modify anything. Following are the steps for setting up the SMI (MIB and PIB) Path

1. Open Wireshark. The main window of the GUI Interface has menus.
2. Go to Edit menu → Preferences as shown below:

   

3. Now Select Name Resolution from the left panel as shown below:
   
4. When you select Name Resolution from the left panel then the right side will show the various settings including SMI (MIB and PIB) paths at the bottom as shown above.
5. Now Click on the Edit. button located after the SMI (MIB and PIB) Path. The following dialog box appears:
   
6. Click on “+” to add path from the folder stored in your local computer. The path is Program Files/ Wireshark/snmp/mibs copy it and paste as shown above.

   Functions of SMI:

   The following are the functions of Structure of Management Information (SMI) Numbers (MIB Module Registrations):-

   • The specification of one or more paths to the SMI modules leads to the management of hosts and Internet gateways.
   • A data structure is required for the management of hosts and Internet gateways. The information has a defined structure. Using this, the data structure should be utilized with any of the many potential management methods, including a “Simple Network Management Protocol” (SNMP) [RFC1157], or the [RFC1095] “Common Management Information Protocol over TCP” (CMOT).
   • The data structure is “Structure and Identification of Management TCP/IP-based Internet information “(SMI) [RFC1155], along with the “Management Information Base for TCP/IP-based Network Management Internets “MIB II (RFC 1213).
   • The SMI contains a clause that allows for parameters or codes to indicate data structures that are experimental or proprietary. Assigning these parameters a list of them is mentioned below.
   • A data format was also specified in the earlier “Simple Gateway Monitoring Protocol” (SGMP) [RFC1028]. For historical completeness, the parameter assignments used with SGMP are presented below.
   • The name space’s iso (1), org (3), dod (6), internet (1), or 1.3.6.1 branch contains the network management object identifiers.
   • According to RFC 1157, 1.3 is labelled as “org” in the following table. The ASN.1 notation for 1.3 is “identified-organization” in the OID standard, which is ITU-T guideline X.660.

   Sr. No.	Assignments	Parameters
   1.	1	iso
   2.	1.3	org
   3.	1.3.6	dod
   4.	1.3.6.1	internet
   5.	1.3.6.1.1	directory
   6.	1.3.6.1.2	mgmt
   7.	1.3.6.1.2.1	mib-2
   8.	1.3.6.1.2.1.2.2.1.3	ifType
   9.	1.3.6.1.2.1.10	transmission
   10.	1.3.6.1.2.1.10.23	transmissionppp
   11.	1.3.6.1.2.1.27	application
   12.	1.3.6.1.2.1.28	mta
   13.	1.3.6.1.2.2	pib
   14.	1.3.6.1.3	experimental
   15.	1.3.6.1.4	private
   16.	1.3.6.1.4.1	enterprise
   17.	1.3.6.1.5	security
   18.	1.3.6.1.6	SNMPv2
   19.	1.3.6.1.6.1	snmpDomains
   20.	1.3.6.1.6.2	snmpProxys
   21.	1.3.6.1.6.3	snmpModules
   22.	1.3.6.1.7	mail
   23.	1.3.6.1.8	features

   Conclusion: 

   SMI outlines the standards for describing management information (the MIB). The SMI displays the MIB database structure as a tree having conceptual tables, with each managed resource represented by an object. MIB Modules are the highest level structure in a MIB specification, likewise PIB Modules are the same. A typical SNMP or COPS device supports many modules, each of which contains related specifications for a subset of that device’s capability, which is frequently shared with other similar devices. Most SNMP devices, for example, support IF-MIB, which defines a collection of objects for managing network interfaces in the device. Moreover, Wireshark automatically picks the default SMI path for your system.