Does anybody have used that book? I think there's a typo in the "Configuration example: InterVLAN Communication" exercice, page 48.
If you take a look at it, L2Switch2 has 4 VLANs in the 172.16.x.0/24 network. But the workstations have IP addresses that belong to the 192.168.x.0 network.
Besides, subinterfaces on the CORP router have 192.168.x.0 network addresses.