Raspberry Pi and Quectel EC25 Modem: DNS Failure on wwan0 Interface
In this article, we will discuss a common issue that arises when using a Raspberry Pi with the Quectel EC25 modem and how to troubleshoot the DNS failure on the wwan0 interface. We will cover key concepts, provide detailed context, and use subtitles to help guide you through the process.
Background
The Raspberry Pi is a popular single-board computer that can run various Linux distributions, including the latest Raspberry Pi OS. The Quectel EC25 modem is a high-performance LTE Cat 4 module that can be used to connect the Raspberry Pi to the internet via a cellular network.
Issue: DNS Failure on wwan0 Interface
When using the Quectel EC25 modem with a Raspberry Pi, you may encounter a DNS failure on the wwan0 interface. This means that while the modem can connect to the internet, it cannot resolve domain names to IP addresses, making it impossible to access websites using their domain names.
Troubleshooting the DNS Failure
To troubleshoot the DNS failure on the wwan0 interface, you can try the following steps:
- Check the connection: Make sure that the modem is properly connected and that the SIM card is active. You can test the connection by running the
ping 8.8.8.8command. If the ping is successful, then the connection is working, and the issue is likely related to DNS. - Check the DNS settings: Verify that the DNS settings are correct. You can do this by running the
cat /etc/resolv.confcommand. The output should show the DNS servers that the Raspberry Pi is using. If the DNS servers are not specified, you can add them manually by editing the/etc/network/interfacesfile. - Restart the network: If the DNS settings are correct, try restarting the network by running the
sudo systemctl restart networkingcommand. This will restart the network and may resolve the DNS failure. - Update the firmware: If the DNS failure persists, it may be due to an outdated firmware. You can update the firmware by following the instructions provided by Quectel. This may involve downloading the latest firmware from the Quectel website and installing it using a tool such as the Quectel Firmware Upgrade Tool.
The Quectel EC25 modem is a powerful LTE Cat 4 module that can be used to connect a Raspberry Pi to the internet via a cellular network. However, you may encounter a DNS failure on the wwan0 interface when using the modem. By following the troubleshooting steps outlined in this article, you can resolve the DNS failure and get back online.