The following checklist is to configure LLT over UDP:
For UDP6, the multicast address is set to "-".
Make sure that each NIC has an IPv6 address that is configured before configuring LLT.
Make sure the IPv6 addresses in the /etc/llttab files are consistent with the IPv6 addresses of the network interfaces.
Make sure that each link has a unique not well-known UDP port.
For the links that cross an IP router, disable multicast features and specify the IPv6 address of each link manually in the /etc/llttab file.