I have to admit there is actually some. Luckily though, when we saw problems, recent updates (i.e. mosh, ping, etc.) actually fixed them. However there is some

I have to admit there is actually some. Luckily though, when we saw problems, recent updates (i.e. mosh, ping, etc.) actually fixed them. However there is some really broken software out there that hard codes IPv4 addresses - which even breaks NAT64/DNS64!