The .iso is for the latest debian bullseye, taken from
https://cdimage.debian.org/debian-cd/current/i386/iso-dvd/
- Bug#1017540: cdimage.debian.org: i386 DVD 1 iso fails to in... dominik
- Bug#1017540: cdimage.debian.org: i386 DVD 1 iso fails ... Steve McIntyre
- Bug#1017540: Clarification Dominik Wrona