freeSWAN

hi there i wanted to establish a freeswan tunnel and i've tried everything suggested in documentation but it won't work... (boring question, i know) both boxes are masqued 'firewalls' running ipchains and suse6.3. each box has rules to accept the other's private and official addresses as 'trusted' (suse firewall script). ipsec seems to be set up correctly, turning on debug does not make failure output and the route is correct, too. traceroute stops at the ipsec0 device. if i ping the other's private net packets will only reach ipsec0. does anybody know what i could do? does anybody know tools to check if routers inbetween drop ipsec packets? Bjoern