GS748T Software User Manual
4-16 Configuring the Switch
v2.0, April 2007
The GS748T switch supports Rapid Spanning Tree Protocol (defined by IEEE 802.1w), which is
an improvement (over the 802.1D STP) that shortens connection latency between nodes. The
resultant path between nodes determined by RSTP is the same as that eventually determined by
STP. The following concepts are associated with this protocol.
• Fast Link: When a port running the standard Spanning Tree Protocol (STP) is connected, it
will go through the STP negotiation (listening -→ learning → forwarding or blocking) before
it is fully available. If a server is trying to access a client through the switch running the STP
negotiation, it is not able to connect to it immediately. This can be a problem for some
networks. Fastlink mode solves this problem by setting the port directly to forwarding mode,
thus allowing any server access request to be forwarded. Fastlink mode can cause temporary
loops in your network, but the STP eliminates them. Fastlink is best used on end node ports,
i.e. ports connected to PCs or servers, to avoid network loops.
• Bridge Priority: Priority setting of this switch in the Spanning Tree.
• Bridge Max Age: Amount of time before a configuration message is discarded by the system.
• Bridge Hello Time: Interval between configuration messages sent by the Spanning Tree
algorithm.
• Bridge Forward Delay: Amount of time system spends in 'learning' and 'listening' states.
• Path Cost: The switch uses this to determine which port is the forwarding port. All other
factors being equal, the path with the lowest cost to the root bridge is the active path.
• Path Priority: STP bases on this to determine the port to use for forwarding. The port with the
lowest number has the highest priority.
The IEE 802.1W RSTP Setting page of the GS748T switch contains a set of default values which
are optimal for most applications. Adjust these values if you must provide for special conditions.