Table of Contents
Set up and use SNMP on the router
Goal
Setting up the SNMP function on the router so that you can then query OID. For this, all installation steps on the server and client side are shown. Node RED is used in the second step for a web-based display.
Prerequisites
For the implementation with Node RED in the second step
- NetModule Wireless Router with wireless connection
- NetModule Software 4.9.0.x or newer
- A license is required for the LXC container
- Not available for legacy products NB1600, NB2700, NB3700, NB3710
The wiki was tested with router software 4.9.0.102 and the LXC container with Debian armhf bookworn.
1. Set up SNMP on the router
Enable the SNMP function on the router.
You can add information to the two parameters “Contact” and “Location”.
For the “Operation mode” parameter, you can restrict the query options.
For the “Listening port” option, you can specify a port other than the standard port 161. It is important that you then always specify the port when making a request. Otherwise, a client would always use port 161 for the request if it is not specified.
Further settings can be stored under the “Authentication” tab.
If you need more than just reading rights and need to query deeper structures of the OID. Must be activated for the admin account to access.
The question of who can make a request can be restricted again using “Allowed host”. In this test, access was granted to everyone.
To access it, you have to make a change in the user administration.
Please select the pencil icon on the right.
Under this mask, you have to enable the “Store password unencrypted” option for the SNMP query.
The server side of SNMP would then be set up for the time being.
For more information, you can also refer to the manual.
- NetModule manual 4.6.0.108 Manual PDF or
- NetModule manual 4.8.0.103 Manual PDF
2. Setting up the SNMP client side for the query
The queries are carried out via a Linux client on the console.
To do this, you need to install a few programs and adjust a few settings. Debian is used as the Linux system.
The “snmp” package must be installed for the query. The command
“sudo apt-get install snmp” installs the program with all the necessary components.
Next, please install the standard MIB file for SNMP on the computer. This is set up with the command “sudo apt-get install snmp-mibs-downloader”.
Now you still need to customize settings and store the NetModule MIB file on the computer.
First create a subdirectory in the Linux user's home directory. It is important that the file name is .snmp. The dot before the name is important for the file.
Please change to the directory .snmp with the command “cd”
Now a subdirectory for the NetModule MIB file must be created with mkdir.
Next, a snmp.conf control file for the MIB file is still needed. This can be created using the “vi” program.
Output file contents :~/.snmp$ cat snmp.conf mibs +NB-MIB
This entry “mibs +NB-MIB” must then be stored in this config file so that the NetModule MIB can then be accessed during queries.
You can download the NetModule MIB directly from the router.
The MIB file that you have downloaded still has to be stored in the SNMP subdirectory. This can be done with this command.
:~/.snmp$ ls mibs snmp.conf
:~/.snmp$ ls mibs/ VENDOR-MIB.txt
3. Run some SNMP queries for testing and to see which queries are possible
For the first request a snmpwalk is used.
The second query is to test whether the NetModule MIB is stored and can be used.
If the OID is needed, you can cancel the resolution to the name or you can translate the name into an OID directly.
:~$ snmptranslate -On -IR serialNumber.0 .1.3.6.1.4.1.31496.10.40.3.0
If a query is to be carried out with SNMP v3
:~$ snmpget -v3 -l authNoPriv -u admin -a SHA -A admin2024 192.168.1.1/ serialNumber.0 NB-MIB::serialNumber.0 = STRING: 00112BFFDF16
4. Setting up an LXC container and then implementing Node RED
The link below takes you to a wiki that describes how to install and set up an LXC container on a NetModule router.
* Set up an LXC container / set-up-lxc
Once the LXC container has been installed, we can install Node-RED.
For further installation, we need the curl program and the npm package on the container. We will then deploy Node-RED on the router using a script.
Next, the Node-RED program is installed via a script file.
Further information on the installation script can be found at this link.
* Node-RED script information github link
Node-RED core is installed in version 4.0.9 and Node.js in version 18.19.0.
The script command for this:
bash <(curl -sL https://raw.githubusercontent.com/node-red/linux-installers/ master/deb/update-nodejs-and-nodered) --node18
The first question is whether the installation should be carried out under
the “root” user. We only have the “root” user in the container, so
the answer is yes.
Are you really sure you want to install as root ? (y/N) ? y
yes here
Are you really sure you want to do this ? [y/N] ? y
I don't have a Pi where I install Node-RED on it, so no here
Would you like to install the Pi-specific nodes ? [y/N] ? n
Stop Node-RED \u2714 Remove old version of Node-RED \u2714 Remove old version of Node.js \u2714 18.19.0+dfsg-6~deb12u2 Install Node 18.20.6-1nodesource1 \u2714 v18.20.8 Npm 10.8.2 Clean npm cache \u2714 Install Node-RED core \u2714 4.0.9 Move global nodes to local - Npm rebuild existing nodes \u2714 Install extra Pi nodes - Add shortcut commands \u2714 Update systemd script \u2714 Any errors will be logged to /var/log/nodered-install.log
All done.
Further settings for the Node-Red interface
The script command for this:
root@LXCNAME:~# /usr/bin/node-red admin init
User Security ============= ? Do you want to setup user security? … ▸ Yes ▸ No
? Add another user? … ▸ Yes ▸ No
✔ Do you want to enable the Projects feature? · Yes ? What project workflow do you want to use? … ▸ manual - you must manually commit changes ▸ auto - changes are automatically committed
Node settings ============= ? Allow Function nodes to load external modules? (functionExternalModules) … ▸ Yes ▸ No
If you want to test the whole thing first, you can start the Node-RED server manually by entering the command “node-red-start”.
If you want this to happen automatically when you start the LXC container, you have to set it up with the command “systemctl enable nodered.service”.
Once you have stored the systemctl for Node-RED, you still have to restart the container for the service to start.
You can access the Node-RED interface via a web browser. Simply enter the IP address of the container and port 1880.
The Node-RED interface will then be displayed.
5. Installing further app-nodes via palette management
For Node-RED, further “app nodes” need to be installed.