Can’t see VPN traffic

set up as follows:

private network --> DDWRT Router with VPN --> HUB --> A regular router --> Internet

The hub is true hub (netgear EN108). I have a laptop running wireshark on the hub monitoring traffic between the routers. Problem is wireshark is not capturing any of the packets to/from the VPN router when the traffic is going through the tunnel. I CAN see packets between the routers when that traffic is outside the tunnel. example, the route tables are set up so that i can ping the outer router from the private network - those icmp packets flow outside the vpn tunnel, and wireshark sees them. why am I not seeing any encrypted packets for the rest of the traffic that flows through the VPN tunnel???