What i found out, on a Server L i could Add additional IP Adresses to eth0:0 and eth0:1 and that server works without problems since days now. On a Server XXL it seams not to be possible to add Adresses to eth0:0 and eth0:1 - it always adds them to eth0... i could not get it to work there even after reinstall... what server are yours that make problems IF your have Servers @ IONOS?