Per-VLAN Spanning Tree (PVST) & Per-VLAN Spanning Tree Plus (PVST+)

1. Per-VLAN SpanningTree (PVST)
&
Per-VLAN SpanningTree Plus (PVST+)

2.  The type of a single instance Spanning Tree Protocol (STP) is
known as Common SpanningTree (CST).
 Delay in receiving BPDUs is common in large switched Common
SpanningTree (CST) networks.
 The delay in receiving BPDUs can cause problems like
convergence time problems.
 Per-VLAN SpanningTree (PVST) is a solution for these problems.
 Per-VLAN Spanning Tree (PVST) is a Cisco proprietary Spanning
Tree Protocol (STP) which operates a separate instance of
SpanningTree Protocol (STP) for each individualVLAN.

3.  A separate instance of Spanning Tree Protocol (STP) for each
VLAN helps VLAN to be configured independently and also can
perform better.
 Per-VLAN SpanningTree (PVST) requires Inter-Switch Link (ISL).
 Per-VLAN Spanning Tree+ (PVST+) is an extension of the PVST
standard.
 Per-VLAN Spanning Tree+ (PVST+) allows interoperability
between CST and PVST in Cisco switches and support the IEEE
802.1Q standard.