Ping Failure!!

Hi,
Am trying to ping between AIX and FreeBSD7.4/i386 by IPv6 address..
It is unable, I configured all files like /etc/rc.conf at freebsd and /etc/hosts and etc/netsvc.conf and restarted the IPv6 network at AIX..
Please help me where I have missed the procedure..

Well, are they on the same subnet or different?
How are they connected?
What are the networking devices sitting in between?

Ping is two-way communication: one packet goes to the target machine and the response from that machine comes back to the machine you are on. If something happens to either of the packets, ping fails. Without the minimum knowledge of your network schema, it's hard for anyone to solve such an issue.