debian-installer-netboot-arm64 software package provides virtual package provided by debian-installer-8-netboot-arm64, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install debian-installer-netboot-arm64
debian-installer-netboot-arm64 is installed in your system.
Make ensure the debian-installer-netboot-arm64 package were installed using the commands given below,
$ sudo dpkg-query -l | grep debian-installer-netboot-arm64*
You will get with debian-installer-netboot-arm64 package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Virtual packages |
| Package | debian-installer-netboot-arm64 |
| Version | |
| Description | virtual package provided by debian-installer-8-netboot-arm64 |
| Sub Section | Virtual |