FAQ

How to reinstall an opkg package?

To reinstall an opkg package use the following command:

opkg install <package_name> --force_reinstall

Being the <package_name>, the name of the package that you want to reinstall.

How to start/stop/restart Node-RED?

Start the Node-RED service with
```
systemctl start node-red
```
Stop the Node-RED service with
```
systemctl stop node-red
```
Restart the Node-RED service with
```
systemctl restart node-red
```
Check Node-RED service status with
```
systemctl status node-red
```

Where to store my projects in the eManager?

If you have an eManager Pro you can access to the /data partition.

Otherwise, if your eManager is not the Pro version, you can use the following directory:

/usr/etc/<your_project_dir>

Being <your_project_dir>the desired directory where the user wants to save their data and projects.

How to configure port forwarding?

See this section.

How to check the coverage level of the modem?

See this section.

How to change the journald logs from volatile to persistent?

The use of persistent logs should be limited in time. Revert the changes to avoid running out of flash.

If our eManager is configured with volatile logs and we want to change it to persistent logs, the following steps must be followed:

Update your eManager with
```
opkg update
opkg upgrade
```
Edit the /etc/systemd/journald.conf.d/journald.conf file by appending the following lines
```
Storage=persistent
ForwardToSyslog=yes
```

Execute the following commands:

systemctl stop systemd-journald.service
rm /var/log
mkdir /var/log
cp -R /var/volatile/log/* /var/log
sync
systemctl start systemd-journald.service

In order to turn the persistent journald logs into volatile again follow these steps:

Edit the /etc/systemd/journald.conf.d/journald.conf file by deleting the lines
```
Storage=persistent
ForwardToSyslog=yes
```

Execute the following commands:

systemctl stop systemd-journald.service
cd /var/
cp -R log/* volatile/log/
rm -fr log
ln -s volatile/log/ log
sync
systemctl restart systemd-journald.service

If you want more information about using journalctl commands to view and manipulate systemd logs, please check here.

How to install an opkg package in the eManager?

First of all, you can check which packages are already installed in your eManager using:

opkg list_installed

The list of packages that can be opkg-installed is here. You can also run:

opkg update
opkg list

in your eManager.

To install a new package execute:

opkg update
opkg install <package_name>

where <package_name> is the name of the desired package obtained from the list of available packages.

How to reinstall the original version of npm?

eManager images support very specific versions of npm. Updating npm without the official opkg package manager can lead to unstable behaviour.

In order to reinstall the npm version supported by the eManager execute the following commands in the eManager console with Internet connection:

opkg update && opkg upgrade
opkg install nodejs-npm --force-reinstall
systemctl restart node-red

How to access the eCore/eManager without knowing the IP?

eCore/eManager is designed to be managed via local Wifi/Ethernet network, hence IP addresses are crucial. Nevertheless, if the IP is not known one can still use the [HOSTNAME].local instead.

eCore/eMananager hostnames follow the pattern

[MODEL]-[MAC_ADDRESS_SIX_LAST_DIGITS]

where MODEL is one of:

eCore
eManager
eManager-Pro

and MAC_ADDRESS_SIX_LAST_DIGITS is a string consisting of the six last digits in the eCore/eManager MAC address.

The hostname can be used as a URL (the path in a web browser) to access the eCore/eManager by adding .local.

Accessing Node-RED (eManager only)

An eManager-Pro with MAC address F8DC7A313CE8 has hostname eManager-Pro-313CE8. In order to access the Node-RED editor of this eManager one can use the URL:

eManager-Pro-313CE8.local:1880

Accessing OTA Firmware Update (eCore only)

In order to access the OTA Firmware Update of an eCore with MAC address F8DC7A2CEFC7 you can use the URL:

http://eCore-2CEFC7.local/ota

How to install SQLite Node-RED node in the eManager?

To install the SQLite node in the eManager, the following steps must be followed:

Update eManager packages using:
```
opkg update
```

Install core-buildessentials package using:

opkg install packagegroup-core-buildessential

Install SQLite package using:
```
opkg install sqlite3
```

Install SQLite node in Node-RED using:

This step may take around 20 minutes.

systemctl stop node-red
cd /var/lib/node-red/
npm install node-red-node-sqlite
systemctl start node-red

How to include certificates in the eManager?

You can find the system certificates in the following path:

/usr/share/ca-certificates/mozilla

To add certificates in Linux, you must copy the certificate in the /usr/local/share/ca-certificates/cert.crt path and run:

sudo update-ca-certificates

To add certificates to Node-RED you must set an enviromental variable called NODE_EXTRA_CA_CERTS to the certificate path as follows:

NODE_EXTRA_CA_CERTS=/usr/local/share/ca-certificates/cert.crt

How to install a Node-RED node without using palette manager?

In order to install new nodes through the console (without using palette manager graphical interface) use the following command:

npm install --no-audit --no-update-notifier --save --save-prefix="~" --production <NODE_NAME> --prefix /var/lib/node-red

where <NODE_NAME> is the name of the Node-RED node to be installed.

For example, in order to install the dashboard-evi@1.0.2 node, execute:

npm install --no-audit --no-update-notifier --save --save-prefix="~" --production dashboard-evi@1.0.2 --prefix /var/lib/node-red

How to access an eManager from the Internet?

An eManager will typically be configured with a private IP, within one of the following ranges:

Class A: 10.0.0.0 to 10.255.255.255 (10/8 prefix)
Class B: 172.16.0.0 to 172.31.255.255 (172.16/12 prefix)
Class C: 192.168.0.0 to 192.168.255.255 (192.168/16 prefix)

To be able to access an eManager from the Internet it should have a public IP. The problem that must be taken into account when assigning a public IP is that it becomes vulnerable to hacker attacks, leading to security problems.

To avoid these security issues, it is recommended to create your own VPN or hire one.

You can find more information about how to create your own VPN here.

Set a different default fixed IP address

The eManager is configured with a static IP address 10.1.10.10 via Ethernet. This can be checked with

ip -c address  # using -c option for coloring `ip -c a` for short.

Notice the pink 10.1.10.10 IP in the 2: eth0 Ethernet interface section.

How to modify the static IP address

New in image release 22.10.

The NetworkManager built-in CLI nmcli is the perfect tool for modifying network settings via terminal.

In order to modify the static address for the Ethernet interface use the following command:

nmcli connection modify emod_eth0 ipv4.addresses <new_static_IP>

where <new_static_IP> is the new static IP address to use.

Persistent changes

Changes made by nmcli connection modidy [...] will be persistent to reboots but will not have immediate effect. In order for the changes to take effect it is enough to reboot the eManager, restart the NetworkManager service or use the command below.

Finally, use

nmcli connection up emod_eth0

for reactivating the Ethernet connection.

Connection Loss

If accessing eManager terminal via the default 10.1.10.10, this last command should produce connection loss. Your previous session has no longer access to 10.1.10.10 and will eventually be closed.

Now the eManager should be accessible via

ssh root@<new_static_IP>

You can also check that <new_static_IP> appears in the output of ip -c a instead of 10.1.10.10.

How to add an additional static IP address

New in image release 22.10.

NetworkManager can handle multiple static IP addresses. In this example we show how to add the secondary static IP address 192.168.122.11 for the subnet 255.255.255.0 (/24 for short).

nmcli connection modify emod_eth0 +ipv4.addresses "192.168.122.11/24"
nmcli connection up emod_eth0

Use ip -c a to check the changes. ip a after adding a new IP address

How to remove a static IP address

New in image release 22.10.

In this example we show how to remove the secondary static IP address 192.168.122.11 we added in the section above.

nmcli connection modify emod_eth0 -ipv4.addresses "192.168.122.11/24"
nmcli connection up emod_eth0

After some seconds it won't appear at the ip -c a output anymore.

How to modify routes/metrics

Experts only

What follows is a list of typical use cases for nmcli/ip that manipulate networking routes and metrics. The reader is expected to be familiar with these concepts.

Add static routes (persistent)

New in image release 22.10.

Some networks may require special networking routes in order to reach particular resources. For example, in order to route the traffic for the 192.168.122.0/24 subnet to the gateway at 10.10.10.1 execute

nmcli connection modify emod_eth0 +ipv4.routes "192.168.122.0/24 10.10.10.1"
nmcli connection up emod_eth0

Modify routes (not persistent)

ip route gives the main information for the current IP routes. By appending add/del to it one can add new routes or deleting existing ones. Bear in mind that this changes won't persist after system or network reboots.

Here are some examples:

ip route add default via 192.168.1.60 dev eth0 metric 50 # adds a route with metric and is explicitly specified that corresponds to the Ethernet interface
ip route del default via 192.168.1.60 dev eth0 metric 50 # deletes a route 
ip route add default via 192.168.1.60 metric 100         # adds a route with metric

How to revert changes

In order to revert the changes made by ip it is enough restart the server:

systemctl restart NetworkManager

Modify interface metric (persistent)

New in image release 22.10.

The NetworkManager logical connections are called emod_eth0 and emod_wlan0 by default in the eManager.

In order to modify the Ethernet connection metric execute

nmcli connection modify emod_eth0 ipv4.route-metric 50
nmcli connection up emod_eth0

In order to modify the Wi-Fi connection metric execute

nmcli connection modify emod_wlan0 ipv4.route-metric 50
nmcli connection up emod_wlan0