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Disabled - Not strictly part of STP, a network administrator can manually disable a
port
802.1w RSTP
In 1998, the IEEE with document 802.1w introduced an evolution of the Spanning Tree Protocol:
Rapid Spanning Tree Protocol (RSTP), which provides for faster spanning tree convergence after
a topology change. Standard IEEE 802.1D-2004 now incorporates RSTP and obsoletes STP.
While STP can take 30 to 50 seconds to respond to a topology change, RSTP is typically able to
respond to changes within a second.
RSTP bridge port roles:
Root - A forwarding port that is the best port from Nonroot-bridge to Rootbridge
Designated - A forwarding port for every LAN segment
Alternate - An alternate path to the root bridge. This path is different than using the
root port.
Backup - A backup/redundant path to a segment where another bridge port already
connects.
Disabled - Not strictly part of STP, a network administrator can manually disable a
port
Edge Port:
They are attached to a LAN that has no other bridges attached. These edge ports transition
directly to the forwarding state. RSTP still continues to monitor the port for BPDUs in case
a bridge is connected. RSTP can also be configured to automatically detect edge ports. As
soon as the bridge detects a BPDU coming to an edge port, the port becomes a non-edge
port.
Forward Delay
:
The range is from 4 to 30 seconds. This is the maximum time (in seconds) the root device
will wait before changing states (i.e., listening to learning to forwarding).
Transmission Limit:
This is used to configure the minimum interval between the transmissions of consecutive
RSTP BPDUs. This function can only be enabled in RSTP mode. The range is from 1 to 10
seconds.
Hello Time:
Set the time at which the root switch transmits a configuration message. The range is from
1 to 10 seconds.
Bridge priority:
Bridge priority is used in selecting the root device, root port, and designated port. The device
with the highest priority becomes the STA root device. However, if all devices have the
same priority, the device with the lowest MAC address will become the root device.
Port Priority:
Set the port priority in the switch. Low numeric value indicates a high priority. A port with
lower priority is more likely to be blocked by STP if a network loop is detected. The valid
