snmp_vacm3

Library

(begemotSnmpdModulePath."vacm" = /usr/lib/snmp_vacm.so)

Overview

The snmp_vacm module implements SNMPv3 View-based Access Control Model MIB as defined in RFC 3415. The module is used to manage the internal lists of SNMPv1, v2c and v3 user names and groups and their access rights to fetch or modify the values of the MIB objects maintained by bsnmpd and the modules loaded in the daemon. The module must be loaded for bsnmpd to implement proper view-based access control. If the module is not loaded, access is granted to all configured SNMPv1 & SNMPv2c communities and SNMPv3 USM users.

Implementation notes

An entry in any table implemented by this MIB may be created by setting the relevant RowStatus column to createAndGo (4) - in fact, any other value for those columns in a SET operation will cause an error. When an entry is created, any of its columns that is not used as index, is set to the default value as specified in the SNMP-VIEW-BASED-ACM-MIB. All entries maintained by the module are persistent after reboot if created via bsnmpd 's config file, otherwise entries created via SNMP are lost after reboot. A short description of the objects in the MIB follows.

vacmContextTable

A read-only table that consists of a list of SNMP contexts available in bsnmpd.

vacmSecurityToGroupTable

The table contains a list of SNMPv1, v2c and v3 user names and the groups they belong to.

vacmAccessTable

The table contains a list of SNMP contexts to groups mappings and respectively the names of the SNMP views under those contexts, to which users in the group are granted read-only, read-write access or receive notifications for the objects under the subtree in the relevant view.

vacmViewTreeFamilyTable

The table contains a list of SNMP views, i.e. entries specifying the OID of a MIB subtree and whether access to the objects under this subtree is to be allowed or forbidden.

Files

/usr/share/snmp/defs/vacm_tree.def

The description of the MIB tree implemented by snmp_vacm.