e.g. if the command is blah put a line in something like: strace blah > /tmp/blah.txt
strace outputs via stderr, so you'll need to do strace blah 2> /tmp/blah.txt I think this is probably overkill, as linesrv is running as root and it uses the same command to bring the ppp interface as Glenn would himself. Glenn: ntpdate will be hanging because it is unable to connect to the server it is trying to. It has a 60 second timeout or something, so after 60 seconds everything should come right. This obviously isn't ideal. It's possible the server you are trying to connect to is part of a round-robin pool, and it's getting a dead server occasionally. If you tell ntp to try several servers at once you should (I think!) improve the odds. Alternatively, you could try a short sleep before running ntpdate, although that might just increase the delay between things working. Finally, you could always background the ntpdate process and carry on. In your ip-up script, put a & after the line that calls ntpdate, etc: /etc/init.d/ntpdate start & This will background the command and let it complete in its own time, and the rest of the process will carry on as normal.