_nmcfg Script

nmcfg

nmcfg is the configuration script that helps the configuration of the SNMP agent. It is particularly useful for the creation and management of SNMPv3 users of the User-based Security Model (USM) and the assignment of VACM (View-based Access Control Model) access rights to communities and users. The script interacts with the /var/netsnmp/snmpd.conf persistent data file, which maintains the USM user database and other SNMP agent persistent information. The script also performs snmpget commands to display the list of USM users, which is not available in a human readable form in any configuration file.

The script also reads and modifies the snmpd.conf configuration file to manage system parameters (contact, location), community-based (v1/v2c) security, and user access control. Used without parameters, it displays a summary of the SNMP agent configuration: system parameters, access control, and SNMPv3 USM users.

Following is an example of the nmcfg configuration script output:

BASH

# nmcfg
system parameter           value
-------------------------- --------------------------------------------------
engineid                   0x80001f88030050c2c611ad 
contact                    "john doe <jdoe@example.net>" 
location                   "QA lab"

model         perm/group        level          user/community       source
------------- ----------------- -------------- -------------------- ---------
usm           guest             auth           guest                -
usm           administrator     priv           johndoe              -
v2c           administrator     noauth         admin                localhost
v2c           administrator     noauth         admin                localnet
v2c           guest             noauth         public               localnet
v2c           rw                noauth         tech                 any

auth protocol 		   priv protocol          user
---------------------- ---------------------- -------------------------------
MD5                    DES                    admin
MD5                    nopriv                 guest
SHA                    AES                    johndoe

# nmcfg help 
usage: nmcfg
nmcfg help
nmcfg access help
nmcfg access usm permit <uname> {<group>|ro|rw} [{noauh|auth|priv}]
nmcfg access usm delete <uname> 
nmcfg community help
nmcfg community permit <community> {<group>|ro|rw} [<host>]
nmcfg community delete <community> [{<group>|ro|rw} [<host>]]
nmcfg system help
nmcfg system define <param> "<value>"
nmcfg system delete <param>
nmcfg user help
nmcfg user define <uname> [{MD5|SHA} "<apwd>" [{DES|AES} ["<ppwd>"]]]
nmcfg user delete <uname>