Security Server

Log in to Security Server via SSH, using the root credentials or another user with administrative privileges, if set.

Make sure no SNMP daemon process is running, and if it is, you must terminate it by using the following command:

root@bitdefender-sva:~# service snmpd stop

Create backup for the /etc/snmp/snmpd.conf file using the following command:

cp /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.bak$

Open the /etc/snmp/snmpd.conf file using a text editor and configure the SNMP daemon to listen on both a local host and an interface IP. By default, the SNMP agent on is set to allow connections originating only from the local host. Search for the line containing the agentaddress and configure it as follows:

sudo nano /etc/snmp/snmp.conf
#agentaddress  127.0.0.1,[::1]
agentAddress udp:127.0.0.1:161,udp:your_interface_IP:161

To create the SNMP v3 user, add the following line in the /etc/snmp/snmpd.conf file :

createUser snmpadmin SHA "your_auth_pass" AES "your_privacy_pass"

Only the following authentication types can be used:

Add the user directive, rouser or rwuser, to allow read-only or read-write access, by adding the following line in the /etc/snmp/snmpd.conf file :

rouser snmpadmin authpriv

The SNMP v3 agent supports the following set of security levels as defined in the official The RFC Series USM MIB (RFC 2574) documentation:

Start the SNMP daemon and check if the user was added in the /var/lib/snmp/snmpd.conf file by using the following command:

root@bitdefender-sva:~#service snmpd start

This is a sample of the snmpd.conf file:

root@bitdefender-sva:~# pgrep snmpd
202826
root@bitdefender-sva:~# service snmpd status
● snmpd.service - Simple Network Management Protocol (SNMP) Daemon.
     Loaded: loaded (/lib/systemd/system/snmpd.service; disabled; vendor preset: enabled)
     Active: active (running) since Mon 2024-01-15 22:09:27 UTC; 11h ago
    Process: 202815 ExecStartPre=/bin/mkdir -p /var/run/agentx (code=exited, status=0/SUCCESS)
   Main PID: 202826 (snmpd)
      Tasks: 1 (limit: 2258)
     Memory: 3.7M
     CGroup: /system.slice/snmpd.service
             └─202826 /usr/sbin/snmpd -LOw -u Debian-snmp -g Debian-snmp -I -smux mteTrigger mteTriggerConf -f -p /run/snmpd.pid
root@bitdefender-sva:~# netstat -nlpu | grep snmp
udp        0      0 10.18.139.1:161         0.0.0.0:*                           202826/snmpd        
udp        0      0 127.0.0.1:161           0.0.0.0:*                           202826/snmpd        
#
# net-snmp (or ucd-snmp) persistent data file.
#
############################################################################
# STOP STOP STOP STOP STOP STOP STOP STOP STOP 
#
#          **** DO NOT EDIT THIS FILE ****
#
# STOP STOP STOP STOP STOP STOP STOP STOP STOP 
############################################################################
#
# DO NOT STORE CONFIGURATION ENTRIES HERE.
# Please save normal configuration tokens for snmpd in SNMPCONFPATH/snmpd.conf.
# Only "createUser" tokens should be placed here by snmpd administrators.
# (Did I mention: do not edit this file?)
#

usmUser 1 3 0x80001f88805b165469ceee666500000000 "snmpadmin" "snmpadmin" NULL .1.3.6.1.6.3.10.1.1.7 0x40b337c3ce06edf6b4fd0ebbbdac5dee06fd4fc67c0b1372b9f76a94ed5cc31234d09edc9c03b59a5b8e89676e501ba6a59f>
usmUser 1 3 0x80001f88805b165469ceee666500000000 "snmpadmin2" "snmpadmin2" NULL .1.3.6.1.6.3.10.1.1.3 0x4707b03a201c155bfabeedce29b16a3e11351661 .1.3.6.1.6.3.10.1.2.4 0x4707b03a201c155bfabeedce29b16a3e >
usmUser 1 3 0x80001f88805b165469ceee666500000000 "snmpadmin3" "snmpadmin3" NULL .1.3.6.1.6.3.10.1.1.3 0x4707b03a201c155bfabeedce29b16a3e11351661 .1.3.6.1.6.3.10.1.2.4 0x4707b03a201c155bfabeedce29b16a3e >
usmUser 1 3 0x80001f88805b165469ceee666500000000 "snmpadmin4" "snmpadmin4" NULL .1.3.6.1.6.3.10.1.1.7 0xa1b0e4c0c34c8af1a395d65a71578468f18bfadd2b5cac1477a0f0817925e01d9178bc4b74b3ad7e91c3f9ef6600176221>
setserialno 582543615

Install SNMPwalk, using the apt install snmp command to test the connection. Make sure there are no other network access related issues while checking if the feature works.

You can now test if the SNMP v3 feature is working by connecting to it from a different machine.

The following are examples of connection tests when the password is correct or incorrect:

Some SNMP packages and network monitoring tools have restrictions related to the use of special characters in passwords. The most common list is: (, ), ;, !, |, $, <, >, ', ", `, \, {, }.

The following is an example of an error displayed by the SNMPwalk feature installed on an Ubuntu machine:

root@administrator-virtual-machine:/home/administrator# snmpwalk -v3 -a SHA -A "!@#4QWEr" -x AES -X "!@#4QWEr" -l authPriv -u snmpadmin SVA_IP | head
bash: !@#4QWEr: event not found

(Optional) To install to install the Management Information Base (MIB) modules for Ubuntu 20.04, you must first uncomment the following repositories, found in the /etc/apt/sources.list.d/ubuntu.list file:

Run the following commands commands to install the modules:

apt-get update
apt -y install snmp-mibs-downloader

Terminate the SNMP daemon process by running the following command:

root@bitdefender-sva:~# service snmpd stop

Add the Security Server into your network monitoring tool and enable it.

Comment the mibs line from the /etc/snmp/snmp.conf file, like in the following example:

root@bitdefender-sva:/etc/snmp# cat snmp.conf
# As the snmp packages come without MIB files due to license reasons, loading
# of MIBs is disabled by default. If you added the MIBs you can reenable
# loading them by commenting out the following line.
#mibs :

# If you want to globally change where snmp libraries, commands and daemons
# look for MIBS, change the line below. Note you can set this for individual
# tools with the -M option or MIBDIRS environment variable.
#
# mibdirs /usr/share/snmp/mibs:/usr/share/snmp/mibs/iana:/usr/share/snmp/mibs/ietf

Start the SNMDP agent using the following command:

root@bitdefender-sva:~#service snmpd start