No internet through GSM connection, possible interface issue - interface

I have a problem with getting GSM connection to work.
Currently used:
Advantech UNO-2272G device
Ubuntu 18.04
NetworkManager/nmcli package
The card works when put in a mobile phone.
*Note: following screenshots are made over SSH and remotely, as the device is currently plugged in ethernet until this issue is resolved.
This is current state of "nmcli" command:
nmcli print
The system connection for GSM is called "radi". My guess is that somehow the interface of that connection is trying to work with the other interface (underlined in red), which in turn is trying to get its DNS conf from router (to which it currently is connected with ethernet, but nothing changes if device is plugged out from router and NetworkManager and network is restarted, it still tries to get to router for its DNS).
This is current state of "ip addr" command:
ip addr
This is current state of /etc/network/interfaces file:
interfaces
This is current state of /etc/NetworkManager/system-connections/radi file:
systemconnection
So, the question is, what am I missing here? Is it the interface issue as written above, or something else entirely?
Disclaimer: I am not that proficient in the stuff presented here, most if not all of it was configured following guidelines on the internet.

Hey I'm not expert in this but I do have a different cellular modem connected to a linux system (RPI) and working with NetworkManager (and ModemManager). My modem was connected by a serial UART port (ttyACM0) so that seems similar to what you have done.
When I configured my cellular connection profile in NM I had to setup the ppp section of the connection profile on top of the gsm part. I also went into my ppp options (on the host) and configured those to match a chat script that came from my modem manufacturer. WHen NetworkManager runs a ppp interface it expects the ppp options for the pppd (daemon) to be configured properly.
Here is the ppp section of my NetworkManager cellular connection settings file. Most are defaults and in my case I only added the baud rate for my modem (since it was connected to a UART).
ppp.noauth: yes
ppp.refuse-eap: no
ppp.refuse-pap: no
ppp.refuse-chap: no
ppp.refuse-mschap: no
ppp.refuse-mschapv2: no
ppp.nobsdcomp: no
ppp.nodeflate: no
ppp.no-vj-comp: no
ppp.require-mppe: no
ppp.require-mppe-128: no
ppp.mppe-stateful: no
ppp.crtscts: no
ppp.baud: 115200
ppp.mru: 0
ppp.mtu: auto
ppp.lcp-echo-failure: 0
ppp.lcp-echo-interval: 0
If this is not helpful then have a look at this thread on NM and routing. In their case eth0 was a local network interface and eth1 was their cellular interface
Now to save you 10 hours of troubleshooting - note that the route
metric is independent of the DNS priority! So if you still have
connectivity issues, make sure it's not a DNS resolution issue (eg.
your DHCP server is providing a dummy resolution service). If it is,
then increase the ipv4.dns-priority of your eth0 connection to make it
lower priority, and/or make sure the ipv4.dns-search of your eth1 is
set to "~" to make it the go-to option.

Related

Is it possible to connect to Modbus TCP via Ethernet?

Is it possible to connect the Ethernet port (of a Raspberry Pi) directly to a Modbus TCP RJ45 port (such that the devices can talk to each other)? Or is this not possible without a converter?
I am unsure if this is the correct forum, but I believe this should not be specific to the Raspberry pi.
Short answer - Yes... But....
As per the comments this is possible but there are a few things you will need to do (i.e. some configuration will be needed).
I think it's worth nothing that "Modbus TCP RJ45 port" is not really a meaningful term. Modbus is an application layer protocol; this depends upon a number of underlying layers:
Transport layer - TCP
Network layer - IP
Datalink Layer - Ethernet
Physical Layer - Ethernet cable with RJ45 connectors
You don't need to understand this in detail; the point is that before ModbusTCP will work you need to have a working TCP network (which all Modbus-TCP devices will support; generally via an RJ45 Ethernet connection). As such a better question probably is "If I run a CAT-5 cable between a Raspberry Pi and another device (Modbus TCP unit) will I be able to connect via TCP?" (a lot more people know about TCP/IP networking than Modbus!).
The first thing to consider is Ethernet. Running a cable directly between two older devices will often not work because they needed a crossover cable. Almost all modern equipment (including the Pi) supports Auto MDI-X which means the cable will just work. You can also connect the units via a switch (and doing this removes the need for Auto MDI-X).
Next you need to consider the IP layer. When you connect your Pi to your home network it will (usually!) be given an IP address by a DHCP service (usually running on your router). If you are connecting the Pi directly to the device then there will be no DHCP service so you will need to manually assign IP addresses to the devices (and ensure the subnet is correctly configured). A common way to check if an IP connection is working is to use the ping command.
With the lower layers working ModbusTCP will generally 'just work'. Many ModbusTCP devices also offer a browser based configuration and checking that you can access that is a good way to confirm that the network link is working.
One further question is probably "should I do this"; it's OK to hook things up this way to make some quick changes. However generally you will want the Pi to access other network resources so connecting everything to a router (home router will work; for remote devices a cell router is often used). You can either give the Modbus unit a static IP manually or use the routers configuration pages to assign it a static DHCP lease (otherwise it's IP might change from time to time).

UDP packets over NB-IoT

I'm trying to send UDP packets over the t-mobile NB-IoT network using AT-commands on a SIM7020E chip. I used the product wiki as reference. The starter version of the sim card I have doesn't support TCP, but I'm planning on using that later if I can succesfully communicate using UDP.
I created a UDP-socket on a Raspberry Pi using "nc -u -l 9999". I set an A-record on my hosting provider to refer dev.mydomain.com to the IP address of the Raspberry Pi. I verified the portforward and A-record settings by sending UDP packets from my laptop on another network using "nc -u dev.mydomain.com 9999" and typing some teststrings, so this all works.
On the 4G chip I use the following AT-commands:
// Check network
AT+CSQ
+CSQ: 21,0
AT+CGREG?
+CGREG: 0,5
AT+COPS?
+COPS: 0,2,"20416",9
AT+CGCONTRDP
+CGCONTRDP: 1,5,"iot.t-mobile.nl","x.x.x.x.255.255.255.0" <-- crossed out my ip
// Create UDP socket
AT+CSOC=1,2,1
+CSOC: 0
// Connect socket 0 to the listening port on the Raspberry Pi
AT+CSOCON=0,9999,"dev.mydomain.com"
OK
// Send "test"
AT+CSOSEND=0,0,"test"
At this point I expect to see "test" appear in the command line on the Raspberry Pi, but nothing happens. In the T-mobile portal it shows a PDP-context is successfully activated.
Also, setting the APN manually with AT*MCGDEFCONT="IP","iot.t-mobile.nl","username","password" doesn't work.
Did you work this out Hans? I was plodding along with a SIM7020E following https://www.waveshare.com/wiki/Pico-SIM7020E-NB-IoT code examples. Was successfully sending HTTP GETS to a server (without having to use micropython's wretched urequests lib) via the CHTTPCREATE/CHTTPCON/CHTTPSEND AT cmds, that seem to be be able to send packets over LTE to a server without specifying TCP/UDP etc or using a socket. Maybe give it a try?
Sadly I got the bright idea of trying an 'AT+POWD=1' cmd over the uart (was supposed to power the 7020E down) & now the module now does nothing but echo AT cmds (still auto connects to the LTE network & slow flashes the network led, just won't do anything else.) Real shame, nice little module otherwise.

Periodically the Internet disappears in the router Mikrotik

Good afternoon need help. There is a router Mikrotik. The Internet and wi-fi started to disappear, but the connection is periodically resumed. The Mac address is specified by my router in an error.
Error in logs : bridge port received packet with own address as source address (ee:ee:8c:0c:ee:fd), probably loop.
You need share a better environment description.
However, assuming you're using wireless interface, you can try proxy ARP on Wireless interface for avoid loops under WiFi bridge.
/interface wireless set arp=proxy-arp
More info here.

2 router in cascade with 2 DHCP and remote access

The installation is in a holidays house (so no permanent internet access)
I have a 4g-Routerm (ROUTER-1 = huawei B525-b23) that enable the internet access. I switch it on one day a week.
I have another router (ROUTER-2 = GL-MT300N-V2).
ROUTER-2 is always plugged on electricity.
On ROUTER-2 is connected through ethernet port a Raspberry-Pi3 (with Home Assistant on it).
On ROUTER-2 is connected through WIFI a Camera IP
ROUTER-1 and ROUTER-2 are connected together through ethernet.
When ROUTER-1 is not plug to electricity, none have acces to internet, but it's not an issue.
The camera save picture on the Rapbery Pi3, the Home Assistat is recording some sensor data.
When I switch on the electricity on the ROUTER-1, everyone have access to internet.
What I want is to have remote Access to my router-2 and my Rasberry and my Camera when ROUTER-1 is online
How should I do ?
Hi I can think of two solutions for this setup but both involve buying a second hand cheap router.
I think the use of a single router would make this setup a lot easier. Any router would work that supports:a USB 4g Modem to be attached to it, and has support for setting up a openvpn server and you need to be OK with leaving the Internet on all the time just make sure you dont have any services running that use up bandwidth and you should be ok. You can can connect both raspberry pi and IP camera to that router. Setup Openvpn server open the UDP port required and download the certificates, You should be able to vpn into your network and manage it through SSH or something remotely.
The second option is tailored to you but still requires swapping the 4G Modem with another one that supports these things: Wake on LAN, openvpn server, supports ssh into it over LAN and either has 4G support through a sim card slot or a usb port with modem support.
You can then have it setup so this new Router-1 is switched off with wake on lan configured on it and the raspberry pi to send the magic packet. You can use something like this to get an idea of how WoL https://www.lifewire.com/wake-on-lan-4149800. You can use cron on your raspberry pi to send WoL signal to Router 1 once a week which would eventually give you internet access once the router is up. You have to setup a vpn server on it and forward the required port and download the certificates. When your scheduled WoL cron runs make sure you are able to connect through vpn then access network resources you wish, at the end when you are done you can ssh into the router-1 and turn it off.
I hope this helps. I had a look at the router models you are using and it doesnt leave you with many options. You can get cheap second hand routers online that support everything that is required.

Passive WiFi detection system using WiFi router

As part of my project requirement I want to make a system which will detect all the WiFi devices in my router range either its connected or not, I did some research on it then I found something like wireshark ,kismate etc I just tried the wireshark by making my Mac machine's WiFi as an adhoc network and its all fine I am able to list all the WiFi devices in wireshark, now I want to make a real-time system based on a real WiFi router I don't know how I will configure my router using my PC and how I will monitor the router from my PC , one more thing if I am using this wireshark how I will use this data for my requirement. If any one worked with similar scenarios please help me..thanks in advance
To do that you will need more than the usual API that you have on commercial WiFi routers (by that I mean a full SSH access). I would:
flash my router with OpenWRT (you can search for your router on this page for detailed instructions)
Install the aircrack-ng suite on the flashed router with
opkg update
opkg install aircrack-ng
Put my WiFi card in monitor mode and run the airodump service:
airmon-ng start wlan0 #Put your NIC in monitor mode
airodump-ng mon0 #Sniff surrounding packets
You don't necessarily have to install aircrack-ng, you can just put your card in monitor mode using command line (look at the documentation for your WiFi driver) and then run tcpdump (command line equivalent to wireshark) but aircrack works very well and has a nice format.
Also, I should warn you that you can brick your router by flashing it. I never had such a problem when flashing router mentioned on the OpenWRT wiki and there are (most of the times) ways to restore a bricked router depending on the brand but I am not responsible if you break it ;)