This guide describes the implementation of the Simple Network Management Protocol (SNMP) applicable to the Cisco 4000 Series Integrated Services Router (ISR) SNMP provides a set of commands for setting and retrieving the values of operating parameters on the Cisco 4000 Series ISR. Router information is stored in a virtual storage area called a Management Information Base (MIB), which contains many MIB objects that describe router components and provides information about the status of these components.
This preface provides an overview of this guide, and contains the following sections:
This guide is intended for system and network administrators who must configure the Cisco 4000 Series ISR for operation and monitor its performance in the network.
This guide may also be useful for application developers who are developing management applications for the Cisco 4000 Series ISR.
This guide contains the following chapters:
“Overview,” provides background information about SNMP and its implementation on the Cisco 4000 Series ISR and a feature history table describing new features implemented since the last Cisco software release.
This section discusses conventions and terminology used in this guide.
Alarm—In SNMP, the word alarm is commonly misused to mean the same as a Trap (see Trap definition). Alarm represents a condition which causes a trap to be generated.
Note Many commands use the word traps in the command syntax. Unless there is an option in the command to select either traps or informs, the keyword traps refers to either traps, informs, or both. Use the command, snmp-server enable <notification>, where notification is either trap or inform, to specify whether to send SNMP notifications as traps or informs.
Element Management System (EMS)—An EMS manages a specific portion of the network. For example, the SunNet Manager, an SNMP management application, is used to manage SNMP manageable elements. Element Managers may manage asynchronous lines, multiplexers, PABX, proprietary systems, or an application.
Informs—Reliable SNMP notifications which are stored in memory until the SNMP manager issues a response. Informs use more system resources than traps.
Management Information Base (MIB)—The objects that are available in an SNMP managed device. The information is represented in Abstract Syntax Notation 1 (ASN.1). It is a way of logically grouping data so that it is easily understood by all.
MIB-II—The enhancements to MIB-I which was the original standard SNMP MIB.
Multiprotocol Label Switching (MPLS)—MPLS is the standardized version of the Cisco original tag-switching proposal. It uses a label forwarding paradigm (forward packets based on labels).
Remote Network Monitoring (RMON) MIB—SNMP MIB for remote management of networks. While other MIBs are usually created to support a network device whose primary function is other than management, RMON was created to provide management of a network. RMON is one of the many SNMP based MIBs that are IETF Standards.
Simple Network Management Protocol (SNMP)—An application layer protocol that allows you to remotely manage networked devices. The word "simple" in SNMP is only in contrast to protocols which are thought to be even more complex than SNMP. SNMP consists of the following components: a management protocol, a definition of management information and events, a core set of management information and events, and a mechanism and approach used to manage the use of the protocol including security and access control.
Synchronous Optical Network (SONET)—A physical layer interface standard for fiber optic transmission.
Trap—SNMP trap is an unsolicited (device initiated) message. The contents of the message might be simply informational, but it is mostly used to report real-time trap information. Traps are used in conjunction with other SNMP mechanisms, as in trap-directed polling, or the SNMP inform mechanism can be used when a reliable fault reporting system is required.
User Datagram Protocol (UDP)—A connectionless, non-reliable IP-based transport protocol.
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