Rapid Pvst+ Bpdus - Cisco Nexus 3000 series Configuration Manual

Configuring Rapid PVST+
Understanding Rapid PVST+

Rapid PVST+ BPDUs

Rapid PVST+ and 802.1w use all six bits of the flag byte to add the role and state of the port that originates
the BPDU, and the proposal and agreement handshake. The following figure shows the use of the BPDU flags
in Rapid PVST+.
Figure 9: Rapid PVST+ Flag Byte in BPDU
Another important change is that the Rapid PVST+ BPDU is type 2, version 2, which makes it possible for
the switch to detect connected legacy (802.1D) bridges. The BPDU for 802.1D is version 0.
Cisco Nexus 3000 Series NX-OS Layer 2 Switching Configuration Guide, Release 5.0(3)U1(1)
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