thanks for that, it kind of figures they are un encrypted, i was at one point going to use this as a solution to a problem but oh well
i found the tutorial on the advanced routing how to at tldp.org
( if you go its called Linux Advanced Routing & Traffic Control HOWTO and its written by a load of people
just one question then, if GRE is unencrypted why do people use it on cisco systems ( i.e. routers, firewalls and switches ), would it not be better to use an encrypted tunnel?