Network Monitor (NEMS)
[traduire]
In my day job, my company has vario network monitoring tools and a large support staff to ensure the network is secure and running properly.
My home network has 80+ devices, which includes multiple switches, APs and lots of smart home automation devices. I have no support staff to keep it running. I want to look at one tool, and quickly know if my network is having issues.
Other Networking:
Step 1. Install a torrent utility
I didn't have torrent on my laptop
Download and install utorrent from www.utorrent.com
Step 2. Download NEMS
Download the bittorrent file for NEMS Latest version of NEMS for the Raspberry Pi
Open Downloads and use utorrent to open the latest file NEMS_*.torrent
Use unarchiver to unzip NEMS_*.zip
Step 3. Setup Raspberry Pi
Follow the directions in the link above, but use the NEMS image from Step 2 instead of raspbian
Step 4. Login
On your laptop, open a terminal window and ssh into the NEMS server using
$ ssh nemsadmin@nems
password: nemsadmin
Run the following command just to see the file system was expanded
$ df -ha
Step 5. Setup NEMS
NEMS setup should start automatically, if it doesn't try:
$ sudo nems-init
Use tab, space and ENTER to make selections. Raspbian requires the UK selections be left. So, don't unselect those
Enter username and password
Record your NEMS Server IP address, or it can be accessed using https://nems.local, which is much easier to remember
Step 6. Check nemsadmin account
Logout and try to login using the default nemsadmin username and password. This shouldn't work
Login with your new username and password
Step 8. Edit the password file to prevent root and nemsadmin from logging in
As a precaution, software downloaded from the internet should have all default usernames disabled. nems comes with root and nemsadmin
Edit the password file and prevent root or admin
$ sudo nano /etc/passwd
and change
root:x:0:0:root:root:/bin/bash
to
root:x:0:0:root:root:/sbin/nologin
and do the same for nemsadmin
nemsadmin:x:1001:1001:,,,:/home/nemsadmin:/sbin/nologin
Step 9. Add all your devices
This is really annoying - auto-discover should be a required feature
Open a browser, and enter the URI https://nems.local, select CONFIGURATION, NMEMS Configurator (NConf). See image at the top of this page, and then a new NEMS Configurator tab should open in your browser
Under Basic Items, add each network element using Hosts Add and completing the required fields marked with *
For address use the hostname.local rather than the IP address
Select Monitored by: Default Nagios
Set "host template(s)" to linux-server
Set "contact groups" to admins
Step 10. Generate the config
Click on Generate Nagios config
If there are errors, click on the bar and fix the errors
If no errors, then click on Deploy
And the servers should be monitored
Go to the Browser window with NEMS Server, and the to Reporting, Nagios Core
Step 11. Add Host Groups
Add host groups.
As an example for my home network: I have 7 TVs. Each TV is smart, and has a Roku, and Kodi running on OSMC as client for TVheadend.
So, I would enter host groups for TV, Roku and OSMC or Kodi.
Step 12. Add NRPE to linux servers
By default, NEMS can ping servers. To get more detailed information, login to a Raspberry Pi or debian linux server (not the NEMS server) and run this command:
$ sudo apt-get install nagios-nrpe-server nagios-plugins -y
Edit this file
$ sudo nano /etc/nagios/nrpe.cfg
and change this line to (my home network range is 192.169.1.0/24 change this to match your network):
allowed_hosts=127.0.0.1,192.168.1.0/24
Restart the nrpe service
sudo systemctl restart nagios-nrpe-server
Step 13. You're done!
A lot can be done with NEMS. The best way is to navigate through the tool and try various features. Decide what you want to monitor and alert on.
Here are some examples:
Add notifications: Open https://nems.local,, go to NEMS System Settings Tool, Notifications
Use Adagios instead of Nagios: Open https://nems.local,, then go to NEMS, Reporting, Adagios
Step 14. Optional - NEMS, Reporting, Adagios
Adagios has a more modern look-and-feel than Nagios
Networking tools
These networking tools are useful:
$ sudo apt-get install snmp -y
$ sudo apt-get install nmap -y
To get hostname, ip address and mac address of everything on the network
$ arp -a