Unable to reach internet using IPv6 network for LAN

This article covers a use case scenario should a customer receive a block of IPv6 global IPs and decides to subnet it for their LAN network.

Service Provider filters traffic on edge routers using prefix-list, since BGP consumes an important amount of CPU, so they filter advertisement routes from client, and packets that don't match the prefix-list are dropped. This means if we do a packet capture on the SonicWall we will be able to see upstream traffic coming from LAN subnet but there is no downstream traffic.

See packet capture done below for more details :

By default, an IPv6 NAT policy is not automatically created when enabling IPv6. Create an IPv6 NAT policy using the following article: LAN to WAN IPv6 traffic need manually add NAT policy.