Understanding Snmp; Snmp Versions - Cisco CISCO1401 - 1401 Router - EN Software Manual

Understanding SNMP

Understanding SNMP
SNMP is an application-layer protocol that provides a message format for communication between
SNMP managers and agents. The SNMP manager can be part of a network management system (NMS)
such as CiscoWorks. The agent and management information base (MIB) reside on the bridge. To
configure SNMP on the bridge, you define the relationship between the manager and the agent.
The SNMP agent contains MIB variables whose values the SNMP manager can request or change. A
manager can get a value from an agent or store a value into the agent. The agent gathers data from the
MIB, the repository for information about device parameters and network data. The agent can also
respond to a manager's requests to get or set data.
An agent can send unsolicited traps to the manager. Traps are messages alerting the SNMP manager to
a condition on the network. Traps can mean improper user authentication, restarts, link status (up or
down), MAC address tracking, closing of a TCP connection, loss of connection to a neighbor, or other
significant events.
This section includes these concepts:
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SNMP Versions

This software release supports these SNMP versions:
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SNMPv2C replaces the Party-based Administrative and Security Framework of SNMPv2Classic with
the Community-based Administrative Framework of SNMPv2C while retaining the bulk retrieval and
improved error handling of SNMPv2Classic.
Both SNMPv1 and SNMPv2C use a community-based form of security. The community of managers
able to access the agent's MIB is defined by an IP address access control list and password.
SNMPv2C includes a bulk retrieval mechanism and more detailed error message reporting to
management stations. The bulk retrieval mechanism retrieves tables and large quantities of information,
minimizing the number of round-trips required. The SNMPv2C improved error-handling includes
expanded error codes that distinguish different kinds of error conditions; these conditions are reported
through a single error code in SNMPv1. Error return codes now report the error type.
Cisco Aironet 1400 Series Wireless Bridges Software Configuration Guide
16-2
SNMP Versions, page 16-2
SNMP Manager Functions, page 16-3
SNMP Agent Functions, page 16-3
SNMP Community Strings, page 16-3
Using SNMP to Access MIB Variables, page 16-4
SNMPv1—The Simple Network Management Protocol, a full Internet standard, defined in
RFC 1157.
SNMPv2C, which has these features:
SNMPv2—Version 2 of the Simple Network Management Protocol, a draft Internet standard,
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defined in RFCs 1902 through 1907.
SNMPv2C—The Community-based Administrative Framework for SNMPv2, an experimental
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Internet protocol defined in RFC 1901.
Chapter 16 Configuring SNMP
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