It doesn’t surprise me at all. Deutsche Bahn got so bad in the recent years that Switzerland started turning some German trains around at Basel (border) to protect its own timetable from DB delays.
Thank you for that useful link. I've bookmarked it as I usually go through the similar steps once in a while and I forget each, what needs to be done exactly.
One of my coworkers, a network specialist, compares IP restrictions to a garden fence. They’re enough to stop casual passersby, but anyone determined will find a way over or around it.