page 3.1.4, Layer 3 Forwarding, Step 4, destined for PC4 should be PC5

http://en.wikipedia.org/wiki/VTP

VLAN
* to create broadcast boundry
* to provide connectivity that is difficult or more costly by physical connections
* to increase security

Trunking
* to provide media sharing among vlans, thus cost effective

VTP
* to manage the VLAN database among participating switches
* mode: server, client or transparent
* domain: name must be the same to join or forward
* version: 1, 2 or 3, must use same version
* password
* sh vtp status
* sh vtp password
* Configuration Revision number: change mode to transparent or change domain name to reset the revision number to 0 before adding to the network
* need trunking port to make it work