While wwwoffle is included as rpm-package it requiered manual action to get it
to work.
The problem is, that wwwoffle doesn't get notified, when the network connection
is build up or teared down. (wwwoffle -online / wwwoffle -offline)

Solution:
I got this solved by putting this as "wwwoffle" in /etc/ppp/ip-up.d
--- snip, snip ---
if [ -x /usr/bin/wwwoffle ]; then
   # Restart to notify of new DNS (is there a better solution ?)
   /etc/rc.d/wwwoffle stop
   /etc/rc.d/wwwoffle start

   # Set the WWWOFFLE HTTP proxy server online.
   /usr/bin/wwwoffle -online -c /etc/wwwoffle/wwwoffle.conf

   # Get the WWWOFFLE HTTP proxy server to fetch requested URLs.
   /usr/bin/wwwoffle -fetch -c /etc/wwwoffle/wwwoffle.conf &
fi
------ snip, snip ----------

And this in /etc/ppp/ip-down.d
------ snip, snip ----------
# Set the WWWOFFLE HTTP proxy server offline.
if [ -x /usr/bin/wwwoffle ]; then
   /usr/bin/wwwoffle -offline -c /etc/wwwoffle/wwwoffle.conf
fi


# Index WWWOFFLE-Cache in Background
umask 022
/var/spool/wwwoffle/search/htdig/scripts/wwwoffle-htdig-full &

# Leaves Log-File in
# /var/spool/wwwoffle/search/htdig/wwwoffle-htdig.log
------ snip, snip ----------

Note: The index part is related to htdig.