As mentioned above, the primary aim of RSTP is to accelerate the activation of network paths once an active connection has failed. RSTP achieves this by dispensing with the states "blocking" and "listening" to reduce the time required to update the network paths to just a few seconds. In case of a network path failure, not all of the links are blocked until the new topology has been calculated; instead, only the failed connections are unavailable for use.
RSTP also enables the administrator to configure information on network topology.
- A bridge port can be defined as an "edge port". An edge port is the only bridge port leading to the connected LAN segment, i.e. no other bridges are connected to the LAN segment, but workstations or servers only, for example. As these ports cannot lead to loops, they change immediately into the forwarding state without waiting for the network topology to be determined. However, RSTP continues to monitor these ports. Should BPDUs be unexpectedly received at an edge port due to another bridge being connected to the LAN, the port automatically returns to its normal state.
- A bridge port can also operate as a point-to-point link. In this case the port is directly connected with an additional bridge. Since no additional stations can occur between the two bridges, the switch into the forwarding state can take place faster.
In the ideal case, RSTP immediately resorts to familiar alternative network paths in case of connection failure.
