VLAN Trunking Protocol (VTP) is a Cisco proprietary protocol
Before using Vlan, VTP or enabling Trunk in the network, below best practices should be kept in mind.
VTP is generally not recommended anymore because of configuration complexity and the potential for catastrophic failure. In other words, a small mistake on the VTP configuration can take whole network down.
If VTP must be used, VTP Transparent mode is best practice because it decreases the potential for operational error.
Always configure VTP Domain name and password.
Manually prune unused VLANs from trunked interfaces to avoid
broadcast propagation.
Don’t keep default VLAN as native VLAN, it protects from VLAN hopping attacks.
Disable trunks on host ports.
Don’t put too many host in one VLAN; keep it small to provide manageable fault domain. In the same VLAN all broadcast unknown unicast packets have to be processed by all the nodes.
If fast convergence is required, don’t use Dynamic Trunking Protocol (DTP). DTP slows down the convergence because switches negotiate the trunking mode.
Why VTP is not recommended?
I have always read to not use VTP because of its risky nature to wipe VLAN configs if improperly configured switches are accidentally placed in production with a newer revision number.
https://www.cisco.com/c/en/us/td/do..._Guide_Release_5-x_chapter4.html#task_1273736