SNMP is an application-layer protocol that facilitates the exchange of management information between network devices and is part of the TCP/IP protocol suite. The Firepower Threat Defense provides support for network monitoring using SNMP Versions 1, 2c, and 3, and support the use of all three versions simultaneously. The SNMP agent running on the Firepower Threat Defense interface lets you monitor the network devices through network management systems (NMSes), such as HP OpenView. The Firepower Threat Defense supports SNMP read-only access through issuance of a GET request. SNMP write access is not allowed, so you cannot make changes with SNMP. In addition, the SNMP SET request is not supported.

You can configure the Firepower Threat Defense to send traps, which are unsolicited messages from the managed device to the management station for certain events (event notifications) to an NMS, or you can use the NMS to browse the Management Information Bases (MIBs) on the security devices. MIBs are a collection of definitions, and the Firepower Threat Defense maintain a database of values for each definition. Browsing a MIB means issuing a series of GET-NEXT or GET-BULK requests of the MIB tree from the NMS to determine values.

An SNMP agent notifies the designated management stations if events occur that are predefined to require a notification, for example, when a link in the network goes up or down. The notification it sends includes an SNMP OID, which identifies itself to the management stations. The agent also replies when a management station asks for information.

The following table lists the terms that are commonly used when working with SNMP.

MIBs are either standard or enterprise-specific. Standard MIBs are created by the IETF and documented in various RFCs. A trap reports significant events occurring on a network device, most often errors or failures. SNMP traps are defined in either standard or enterprise-specific MIBs. Standard traps are created by the IETF and documented in various RFCs. SNMP traps are compiled into the ASA software.

If needed, you can also download RFCs, standard MIBs, and standard traps from the following locations:

http://www.ietf.org/

Browse the SNMP Object Navigator to look up Cisco MIBs, traps, and OIDs from the following location:

https://snmp.cloudapps.cisco.com/Support/SNMP/do/BrowseOID.do?local=en

In addition, download Cisco OIDs by FTP from the following location:

ftp://ftp.cisco.com/pub/mibs/oid/oid.tar.gz