Notice to my future self: If you start the litecoin client (v0.10.2.2) all peers in peers.dat seem to be IPv4 only. At least, I got no connection to the Litecoin network. After looking at the list of supernodes, I could filter two supernodes with IPv6 addresses:
Putting them as
into litecoin.conf, I got my connection and could do some transactions.