Greetings, after noticing huge downloads circa ever 2 minutes naturally I wanted to stop that. :) After a reboot followed by startx which opened icewm I issued the command sudo ngrep -t -d net0 | tee system-ngrep_log.txt in a xterm and waited for one occurrence.
Full log: www.triffids.de/pub/tmp/system-ngrep_log.txt.gz (5,6MB) How to determine the culprit? Hartmut