HP ProCurve 9304M Installation And Configuration Manual page 240

Installation and Basic Configuration Guide
The handshake that occurs between Routing Switch 60 and Routing Switch 100 follows the one described in the
previous section ("Handshake When No Root Port is Elected" on page 8-28). The former root bridge becomes a
non-root bridge and establishes a Root port (Figure 8.9).
However, since Routing Switch 200 already had a Root port in a forwarding state, 802.1W uses the Proposing ->
Proposed -> Sync and Reroot -> Sync and Rerooted -> Rerooted and Synced -> Agreed handshake:
• Proposing and Proposed – The Designated port on the new root bridge (Port4/Routing Switch 60) sends an
RST BPDU that contains a proposing signal to Port4/Routing Switch 200 to inform the port that it is ready to
put itself in a forwarding state (Figure 8.9). 802.1W algorithm determines that the RST BPDU that Port4/
Routing Switch 200 received is superior to what it can generate, so Port4/Routing Switch 200 assumes a
Root port role.
Figure 8.9 New Root Bridge Sending a Proposal Flag
Routing Switch 200
Port2
Routing Switch 300
8 - 34
Routing Switch 100
Port2
Root port
Port1
Proposing
Port1
Root port
Forwarding
Port4
Designated port
Proposed
Port2
Port3
Port3
Handshake Port2
Completed Designated
port
RST BPDU
sent with
a Proposing
flag
Routing Switch 400
Routing Switch 60
Port4
Designated port
Proposing