LibreNMS update to Python 3

You may get the following alert in LibreNMS. Basically you need to install python 3 to keep things up to date.

Python 3 is required to run LibreNMS as of May, 2020. You need to install Python 3 to continue to receive updates. If you do not install Python 3 and required packages, LibreNMS will continue to function but stop receiving bug fixes and updates.

Install Python 3

Install Python 3 with yum, or apt if you are on a Debian based distro.

sudo yum install python3
sudo pip3 install -r /opt/librenms/requirements.txt

Verify LibreNMS is updated and working

Run the following commands to make sure that LibreNMS is working correctly and is up to date.

cd /opt/librenms
sudo ./validate.php
sudo ./

LibreNMS – failed

All the following commands are run from the “/opt/librenms” directory

$ sudo ./ 
Re-running /opt/librenms/ as librenms user
Updating to latest codebase                        FAIL
error: Your local changes to the following files would be overwritten by merge:
Please, commit your changes or stash them before you can merge.

Checking with validate.php shows that you can run githup-remove to fix it

$ sudo ./validate.php
[WARN]  Your install is over 24 hours out of date, last update: Mon, 23 Feb 2020 05:43:12 +0000
         Make sure your cron is running and run ./ by hand to see if there are any errors.
 [WARN]  Your local git contains modified files, this could prevent automatic updates.
         You can fix this with ./scripts/github-remove
         Modified Files:

Run “sudo ./scripts/github-remove -d”

$ sudo ./scripts/github-remove -d
Are you sure you want to delete all modified and untracked files? [y/N] y

You should also be able to remove the files individually if the above command does not work.

Run validate again to make sure it checks out good.

Now run ./

LibreNMS – Setting up Alerts to monitor Voltage on Mikrotik Routers

Create Alert Rule

Go to “Alerts -> Alert Rules” Then “Create rule from Collection”

Search for “Sensor under limit” and Select

Setup Sensor under limit

Configure Alert Rule

Add another rule to limit to just the Voltage Sensors by using the “sensors.sensor_class = Voltage”

Select your Groups and Transports and Save.

Modify Alert Rule

Disable Alerts for Unused Ports

You may get some alerts because there are some ports that do not have any any voltage on them. You can disable them on a per device basis by going to the “device -> Edit -> Health” and turning alerts off

Turn off voltage alerts on port that has no PoE

UNMS – Set user as Super Admin from command line

The following commands can be run from a ssh session to your UNMS instance.

Show Current Users

sudo ~unms/app/unms-cli set-superadmin

Should get something like the following

            UNMS Users
 │ (index) │ username  │           email           │     role     │ two-factor │
 │    0    │  'larry'  │  ''  │   'admin'    │   false    │
 │    1    │   'bob'   │   ''   │   'admin'    │   false    │

Change User to Super Admin

To change a user to a Super Admin, add “–username username” to the above command.


sudo ~unms/app/unms-cli set-superadmin --username bob
            UNMS Users
 │ (index) │ username  │           email           │     role     │ two-factor │
 │    0    │  'larry'  │  ''  │   'admin'    │   false    │
 │    1    │   'bob'   │   ''   │ 'superadmin' │   false    │

Note that there does not appear to be a way to

Raspberry Pi – Ping IP Address and Toggle LED

The following script is for monitoring if an IP address is reachable or not. If it becomes unavailable the script will turn on a LED that is plugged into one of the GPIO pins of the Raspberry Pi. View pinout here


# Script to ping ip address and turn on LED on if device is unreachable.
                                                                                                                                                                                                 nPin="18"  # Change if GPIO pin is different                                                                                                     
ledPin="gpio${nPin}"                                                                                                                                                                                                                            toPing=""  # Change to address you want to ping

echo "${nPin}" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/${ledPin}/direction

if ( fping -r1 $toPing | grep -v alive ); then
         echo "Internet unreachable"
         # Turn on LED
         echo "1" > /sys/class/gpio/${ledPin}/value
         # Turn off LED 
         echo "0" > /sys/class/gpio/${ledPin}/value

Save script as and make it executable.

chmod +x

and run the script.


Run script in crontab

You can setup the script to run every minute using a crontab

crontab -e

Add the following line

*/1 * * * * /home/pi/

Should now execute the script every minute and not need any human interaction.

LibreNMS manually adjust GPS coordinates for a Geo Location

The locations are stored in the LibreNMS locations table

mysql -u librenms -p librenms

To list all the locations

select * from locations;

Set the specific coordinates for a location using the following command.
Replace the lat and lng, also the id should match the line your wanting to update.

update locations set lat = "33.5140",lng = "-86.8178" where id=25;

LibreNMS dump devices in MySQL database

All the devices are stored in the librenms datebase devices table.

You can dump all of them with the following command from a shell prompt.

sudo mysql -u librenms  -p librenms -e "select hostname,sysName from devices"

Example output

[jim@localhost ~]$ sudo mysql -p librenms -e "select hostname,sysName from devices"
 Enter password:
 | hostname                               | sysName                        |
 |                            | linksys                        |
 |                            | wifi-unifi                     |

Install Oxidized on LibreNMS

Install Oxidized

Install Instructions from here

Install prerequisites

sudo yum -y install make cmake which sqlite-devel openssl-devel libssh2-devel ruby gcc ruby-devel libicu-devel gcc-c++

Install Ruby Gems

gem install oxidized
gem install oxidized-script oxidized-web

If you run into issues with installing the oxidized-web gem because of a ruby version, try installing ruby 2.6.1 via rvm the docs say install 2.1.2, but was having issues with it. 2.6.1 seems fine.

Install Oxidized

gem install oxidized 
gem install oxidized-script
gem install oxidized-web

Run Oxidized twice to generate the config


If you have issues running oxidized due to an invalid or self signed ssl cert, you can either fix the cert or ignore it in the oxidized config.

Modify the Oxidized config file in “/root/.config/oxidized/config” to look like this.

Modify the http portion of the config file to look like the following.

url: https://localhost/api/v0/oxidized
scheme: https
secure: false

Setup Config

vi .config/oxidized/config

Setup the config, Basic config below, edit as needed

username: admin
password: password
model: airos
resolve_dns: true
interval: 3600
use_syslog: false
debug: false
threads: 30
timeout: 20
retries: 3
prompt: !ruby/regexp /^([\w.@-]+[#>]\s?)$/
next_adds_job: false
vars: {}
username: ubnt
password: ubnt
username: admin
ssh_port: 2222
models: {}
pid: /home/incredigeek/.config/oxidized/pid
directory: /home/incredigeek/.config/oxidized/crashes
hostnames: false
history_size: 10
default: ssh, telnet
debug: false
secure: false
passive: true
utf8_encoded: true
default: file
directory: /home/incredigeek/.config/oxidized/configs
default: http
debug: false
secure: false
scheme: https
url: https://localhost/api/v0/oxidized
name: hostname
model: os
group: group
X-Auth-Token: '3wq2b87fj4e6fb5987b5812t6ej9709g'
cisco: ios
juniper: junos
mikrotik: routeros

Setup as system service

Find the “oxidized.service” file, should be in


and copy it to


Edit it and change the user and try to launch it

systemctl start oxidized

If it fails, you may need to substitute the ExecStart= variable to the following more info


Change the ruby number if yours is different.

Enable the service on system boot up and start

systemctl enable --now oxidized

Check that oxidized is running

systemctl status oxidized

LibreNMS config

Add the following to your /opt/librenms/config.php config file.

# Oxidized configuration
$config['oxidized']['enabled'] = TRUE;
$config['oxidized']['url'] = '';
$config['oxidized']['features']['versioning'] = true;
$config['oxidized']['group_support'] = true;
$config['oxidized']['default_group'] = 'default';
$config['oxidized']['reload_nodes'] = true;# Oxidized configuration
$config['oxidized']['enabled'] = TRUE;
$config['oxidized']['url'] = '';
$config['oxidized']['features']['versioning'] = true;
$config['oxidized']['group_support'] = true;
$config['oxidized']['default_group'] = 'default';
$config['oxidized']['reload_nodes'] = true;
$config['oxidized']['ignore_os'] = array('linux','windows');
$config['oxidized']['ignore_types'] = array('server','power');

LibreNMS should now feed Oxidized the devices.

You can check in the LibreNMS interface to see if it is getting the configs. https://librenms/oxidized

where librenms is your LibreNMS servers ip/hostname.