D-Link DES-3028 User Manual page 135

DES-3028 DES-3028P DES-3028G DES-3052 DES-3052P Layer 2 Fast Ethernet Managed Switch
The following parameters can be set:
Parameter
Spanning Tree Protocol
Bridge Max Age (6 - 40
Sec)
Bridge Hello Time (1 – 2
Sec)
Bridge Forward Delay (4
- 30 Sec)
Max Hops (6-40)
STP Version
Figure 7- 36. STP Bridge Global Settings window – STP Compatible
Description
Use the pull-down menu to enable or disable STP globally on the Switch. The default is
Disabled.
The Max Age may be set to ensure that old information does not endlessly circulate
through redundant paths in the network, preventing the effective propagation of the new
information. Set by the Root Bridge, this value will aid in determining that the Switch has
spanning tree configuration values consistent with other devices on the bridged LAN. If
the value ages out and a BPDU has still not been received from the Root Bridge, the
Switch will start sending its own BPDU to all other switches for permission to become
the Root Bridge. If it turns out that your switch has the lowest Bridge Identifier, it will
become the Root Bridge. The user may choose a time between 6 and 40 seconds. The
default value is 20.
The Hello Time can be set from 1 to 2 seconds. This is the interval between two
transmissions of BPDU packets sent by the Root Bridge to tell all other switches that it is
indeed the Root Bridge.
The Forward Delay can be from 4 to 30 seconds. Any port on the Switch spends this
time in the listening state while moving from the blocking state to the forwarding state.
Used to set the number of hops between devices in a spanning tree region before the
BPDU (bridge protocol data unit) packet sent by the Switch will be discarded. Each
switch on the hop count will reduce the hop count by one until the value reaches zero.
The Switch will then discard the BPDU packet and the information held for the port will
age out. The user may set a hop count from 6 to 40. The default is 20.
Use the pull-down menu to choose the desired version of STP to be implemented on the
Switch. There are three choices:
STPCompatability - Select this parameter to set the Spanning Tree Protocol (STP)
globally on the switch.
RSTP - Select this parameter to set the Rapid Spanning Tree Protocol (RSTP) globally
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