HP ProCurve 9304M Installation And Configuration Manual page 254

Installation and Basic Configuration Guide
Then FRY1, Routing Switch 5, and Routing Switch 6 send RST BPDUs that contain the TCN to Routing Switch 3
and Routing Switch 4 to complete the TCN propagation (Figure 8.22).
Figure 8.22 Completing the TCN Propagation
Routing S witch 1
Bridge priority = 1000
Port3
Port2
Routing Switch 3
Bridge priority = 300
Compatibility of 802.1W with 802.1D
802.1W-enabled bridges are backward compatible with IEEE 802.1D bridges. This compatibility is managed on a
per-port basis by the Port Migration state machine. However, intermixing the two types of bridges in the
network topology is not advisable if you want to take advantage of the rapid convergence feature.
Compatibility with 802.1D means that an 802.1W-enabled port can send BPDUs in the STP or 802.1D format
when one of the following events occur:
• The port receives a legacy BPDU. A legacy BPDU is an STP BPDU or a BPDU in an 802.1D format. The port
that receives the legacy BPDU automatically configures itself to behave like a legacy port. It sends and
receives legacy BPDUs only.
• The entire bridge is configured to operate in an 802.1D mode when an administrator sets the
• bridge parameter to zero at the CLI, forcing all ports on the bridge to send legacy BPDUs only.
Once a port operates in the 802.1D mode, 802.1D convergence times are used and rapid convergence is not
realized.
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Routing Switch 2
Bridge priority = 200
Port7
Port2 Port2
Port3
Port3
Port4 Port4
Routing Switch 4
Bridge priority = 400
Indicates the active Layer 2 path
Indicates direction of TCN
Port8
Port5
Port4
Port3
Port5 Port5
Routing S witch 5
Bridge priority = 60
Port2
Port3
Port3
Port4
Routing Switch 6
Bridge priority = 900