OK, but is it comparable with the practice of yellow badges? "Whoever wears this sign is an enemy of our people"

https://en.wikipedia.org/wiki/Yellow_badge#/media/File:Die_K...

No, the yellow badges were a way to single out an ethnicity as a way to enforce racial laws such as confiscating their property, removing them from their jobs, allowing other citizens to boycott their businesses and a large target for harassment in the streets. Finally, to achieve the goal of genocide by having identification said ethnicity

While what you are comparing this to, prevents you from entering a website, presumably until you change your DNS to 8.8.8.8

No, it is not comparable. Not at all.

Apart from the blatant qualitative difference, you can't dismiss the context of the holocaust. The intent of displacement and genocide matters, it's not the marking of people per se.

If you can't help yourself and absolutely must use a Nazi reference, a DNS block list is closer related to a book burning, than the planned, industrialized murder of millions of people. But really, censorship isn't the defining characteristic of the Nazi terror, so unless you explicitly want to invoke the topic of ethnic cleansing, I strongly suggest you look elsewhere.