SNMP Community Table Overview

For SNMPv1/v2c, access to an SNMP server by an SNMP client is governed by a proprietary SNMP community table that identifies those communities that have read-only, read-write, or administrative permission to the SNMP MIB stored on a particular server.

When an SNMP server receives a request, the server extracts the client’s IP address and the community name. The SNMP community table is searched for a matching community. If a match is found, its access list name is used to validate the IP address. If the access list name is null, the IP address is accepted. A nonmatching community or an invalid IP address results in an SNMP authentication error.

Each entry in the community table identifies:

This section describes the following:

Community Name

The community name acts as a password and is used to authenticate messages sent between an SNMP client and a router containing an SNMP server. The community name is sent in every packet between the client and the server.

Privilege Levels

SNMP has three privilege levels:

IP Access List

The IP access list identifies those IP addresses of SNMP clients permitted to use a given SNMP community.

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