R6 and R4 Layer 3 connectivity (Task 14.2)

I just doing MPLS lab task 14.2, and found that R4 failed to ping R6. I checked the initial configuration of R4 and R6. There is no VLAN 146 setting on R4 F0/1. Do I need to manually config it?

R4

interface FastEthernet0/1
 ip address 155.1.146.4 255.255.255.0
 no shutdown
  speed 100
 duplex full

R6

interface FastEthernet 0/0.146
 encapsulation dot1q 146
 ip address 155.1.146.6 255.255.255.0