If direct tunnel establishes but fails to pass traffic:
Most consumer routers don't require forwarding for Hamachi (it uses outbound NAT traversal). However, if you have a Symmetric NAT or double NAT, forward UDP 12975 to your PC's local IP. hamachi relayed tunnel to direct tunnel fix
The most common cause is the Windows Firewall blocking the Hamachi client. If direct tunnel establishes but fails to pass