Introduction
The Purism Librem 5 phone is a privacy-focused device that runs PureOS, a Debian-based Linux distribution. This phone has the capability to connect to the internet via an IPv6-only LTE connection. In this article, we will discuss the challenges of setting up an SSH server on the Librem 5 phone and the issues that arise when trying to connect to it from a PC using an IPv4 network.
Setting up an SSH Server on the Librem 5 Phone
To set up an SSH server on the Librem 5 phone, you can use the following command:
sudo apt install openssh-server
Once the SSH server is installed, you can start it by running the following command:
sudo systemctl start ssh
You can also enable the SSH server to start automatically on boot by running the following command:
sudo systemctl enable ssh
Connecting to the SSH Server from a PC
Connecting to the SSH server on the Librem 5 phone from a PC can be challenging, especially if the PC is connected to an IPv4 network. This is because the Librem 5 phone is connected to the internet via an IPv6-only LTE connection. To connect to the SSH server, you can use the following command:
ssh user@ipv6-address
Where "user" is the username on the Librem 5 phone and "ipv6-address" is the IPv6 address of the phone. However, if the PC is connected to an IPv4 network, you may encounter issues connecting to the SSH server.
Issues with IPv4 Networks
If the PC is connected to an IPv4 network, it may not be able to communicate with the Librem 5 phone directly. This is because the phone is connected to the internet via an IPv6-only LTE connection. To overcome this issue, you can use the NAT64/DNS64 protocol, which allows IPv4-only devices to communicate with IPv6-only devices.
To use the NAT64/DNS64 protocol, you can set up a NAT64/DNS64 gateway on your network. This gateway will translate IPv6 addresses to IPv4 addresses, allowing IPv4-only devices to communicate with IPv6-only devices. Once the NAT64/DNS64 gateway is set up, you can connect to the SSH server on the Librem 5 phone using the following command:
ssh user@nat64-address
Where "nat64-address" is the IPv4 address of the NAT64/DNS64 gateway.
Setting up an SSH server on the Purism Librem 5 phone and connecting to it from a PC can be challenging, especially if the PC is connected to an IPv4 network. However, by using the NAT64/DNS64 protocol, you can overcome this issue and communicate with the Librem 5 phone from an IPv4 network.
References
Purism. (2021). Librem 5. https://puri.sm/products/librem-5/
Debian. (2021). PureOS. https://wiki.debian.org/PureOS
IETF. (2015). RFC 7915: NAT64 DNS64 Operation. https://tools.ietf.org/html/rfc7915