When data segment is encapsulated into packet appropriate PC must examine destination address when preparing frame creation. If destination IP is on same network as sending PC data are send to to appropriate host. Else data are sent to network interface that act as a default gateway.
This process use and-ing destination IP in binary format with binary format of network mask and next make comparation with configured network address. If they are unequal data are send to default gateway (MAC address of default gateway is set as destination address of frame). In this scenario you are encouraged to create PDU in simulation mode and examine packet delivery. Interesting are also PDU at appropriate protocol stack (Transport, network and data link layer).
Topology of our scenario is
Preconfigured scenario (PKT 5.2 or above).
When you toggle betw. realtime and simulation mode, interface will change to next picture
After appropriate time used for PDU propagation across network (and ARP caching for L2 encapsulation), PC11 can send frame to Branch fa0/1 interface that act as a default gateway. You can scroll event list and look at PDU emitted by PC11 after ARP process as it show next picture.