To see aiccu's options, use the aiccu-gui... (latest) and type: (I renamed it to aiccug.exe. As mentioned above, it has to be either in the current path or in the search path.) aiccug /? There it shows that aiccug /i installs the service, aiccug /u uninstalls it and aiccug /q shows the aiccu service status. If you are using Windows, use the following command: services.msc Aiccu service is listed as: SixXS Automatic IPv6 Connectivity Configuration Utility Set its type to automatic and then start the service. If it still does not start, check the following options, under Recovery: First failure...............Restart the Service Second failure..............Restart the Service Subsequent failures.........Restart the Service Restart fail count after....0 days Restart service after.......1 minutes Also check Local System account and Allow service to interact with desktop under Log On. Also take care that IPv6 Helper Service starts automatically, with the same options as above. Since it is dependent upon Microsoft IPv6 Protocol Driver, Remote Procedure Call (RPC) and Windows Management Instrumentation, these services also have to start automatically, and WMI and MSIPv6PD should have the same options as above. (If RPC fails to start, your computer will simply reset). It is reccomendable to set it as exception in the Windows firewall. I am behind a router (firewalled), and I run Windows 2003 SP1 (firewalled with default firewall) and I have an unproblematic AYIYA connection. The router seems to support neither proto-41 nor any other IPv6 protocol. I would advise to allow ICMP ping echo (i.e. both in the router firewall and in the Windows firewall), because having your IPv6 endpoint answering pings for one week earns you 5 credits. (Your connection has to be then active each day of that week). I have the following configuration file in my C:\Windows directory: =====BEGIN aiccu.conf===== # AICCU Configuration (Automatically stored by aiccu 2005.01.09) # Login information username ................... password ................... # Interface names to use ipv4_interface (null) ipv6_interface sixxs # The tunnel_id to use # (only required when there are multiple tunnels in the list) tunnel_id .................. automatic true # Be verbose? verbose false # Daemonize? daemonize true # Behind a NAT? behindnat true =====END aiccu.conf===== If you're using AYIYA, the use the latest (i.e. 8.1) TAP drivers for your system (i.e. either 32 or 64 bits). If you have an older driver, use the following command, from C:\Program Files\OpenVPN\bin : deltapall Then uninstall the old TAP driver, restart, install the new TAP driver, run addtap.bat, then restart again and now you're ready to use AYIYA through Aiccu. Running the aiccu-gui executable once before starting the service is in that case a good idea, since it renames the TAP connection to sixxs and (I guess) configures it. And, if stil does not work, then import the following file into registry: =====BEGIN startaiccu.reg===== Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run] "Start AICCU"="cmd /c c:\\startaiccu.bat" =====END startaiccu.reg===== Then make the following batch file: =====BEGIN startaiccu.bat===== Echo Now we wait 5 minutes, as explained by Rob van der Woude. PING 1.1.1.1 -n 1 -w 300000 >NUL net start aiccu regedit /s c:\startaiccu.reg =====END startaiccu.bat======= And put that reg file and the batch file into C:\ Greetings, Tudor