Netgear XCM8810 Chassis User Manual - Page 556

NETGEAR 8800 User Manual A B C A , 0 A , 1 A , 2 Designated port Root port F E D E , 1 A , 4 A , 3 Agree BPDU EX_055f Figure 47. Communicating Port Status to Neighbors 6. To complete the topology change (as shown in Figure 48): • Bridge D moves the port that received the "agree" message into the forwarding state. • Bridge F confirms that its receiving port (the port that received the "propose" message) is the root port, and immediately replies with an "agree" message to bridge E to unblock the proposing port. A B C A , 0 A , 1 A , 2 Root port Designated port F E D A , 5 A , 4 A , 3 EX_055g Figure 48. Completing the Topology Change Figure 49 displays the new topology. A B C A , 0 A , 1 A , 2 Root port Designated port F E D A , 5 A , 4 A , 3 EX_055h Figure 49. Final Network Configuration Compatibility With STP (802.1D) RSTP interoperates with legacy STP protocols; however, the rapid convergence benefits are lost when interacting with legacy STP bridges. Each RSTP bridge contains a port protocol migration state machine to ensure that the ports in the STPD operate in the correct, configured mode. The state machine is a protocol entity 556 | Chapter 18. STP