HP ProCurve 9304M Installation And Configuration Manual page 236

Installation and Basic Configuration Guide
• Sync – Once the Root port is elected, it sets a sync signal on all the ports on the bridge. The signal tells the
ports to synchronize their roles and states (Figure 8.5). Ports that are non-edge ports with a role of
Designated port change into a discarding state. These ports have to negotiate with their peer ports to
establish their new roles and states.
Figure 8.5 Sync Stage
Routing Switch 300
8 - 30
Port1
Designated port
Port1
Root port
Sync
Port2
Sync
Discarding
Port2
Indicates a signal
Routing Switch 100
Root Bridge
Routing Switch 200
Port3
Sync
Discarding
Port3
Routing Switch 400