speedfusion block vlan

Dear all,
I have a peplink1350 snd mini br, my mini br have a 2 lan port
1.1.1.1. and. 192.168.105.1

and I have a speedfusion for both peplink, but can I only limited lan1 can access speedfusion vpn to the 1350?I have created internal firewall rule to block any to 192.160.105.1, but the peplink1350 dtill can ping 192.168.105.1

how can I block it?