User manual

Rapid Spanning Tree
7278_en_01 PHOENIX CONTACT 4-7
Forward Transitions
Indicates how often the port switches from the "Discarding" state to the "Forwarding" state.
Additional parameters provide information about network paths in a stable topology that
are used by the BPDU telegrams.
Designated Root
Root bridge for this Spanning Tree.
Designated Bridge
The switch from which the port receives the best BPDUs. The value is based on the priority
value in hex and the MAC address.
Designated Port
Port via which the BPDUs are sent from the designated bridge. The value is based on the
port priority (2 digits) and the port number.
Designated Cost
It indicates the path costs of this segment to the root switch.
Common
features/differences with
regard to STP
As with STP, a device is also selected as the root for RSTP and every port is assigned a
role according to its participation within the topology.
Port States
The number of port states is also reduced in RSTP. Only the "Forwarding", "Discarding",
and "Learning" states are still available if the network is operated in mixed operation of STP
and RSTP.
Frame duplication Due to the fast switch-over times of RSTP, frames may be duplicated and the order of
frames may be changed.