DGS-3700-12/DGS-3700-12G Series Layer 2 Gigabit Ethernet User Manual
88
STP Version
Use the pull-down menu to choose the desired version of STP to be implemented on the
Switch. There are three choices:
STP
– 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
on the Switch.
MSTP
– Select this parameter to set the Multiple Spanning Tree Protocol (MSTP)
globally on the Switch.
Forwarding BPDU
This field can be
Enabled
or
Disabled.
When
Enabled,
it allows the forwarding of STP
BPDU packets from other network devices. The default is Disabled.
Bridge Max Age
(6-40 Sec)
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
.
Bridge Hello Time
(1-2 Sec)
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 default is
15
.
Bridge Forward Delay
(4-30 Sec)
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.
TX Hold Count (1-10)
Used to set the maximum number of Hello packets transmitted per interval. The count
can be specified from
1
to
10
. The default is
6.
Max Hops (6-40)
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
.
NNI BPDU Address
Configure NNI port address.
dot1d
– Specifies GVRP’s bpdu MAC address of NNI port using the definition of 802.1d.
dot1ad
– Specifies GVRP’s pdu MAC address of NNI port using the definition of
802.1ad.
Click
Apply
to implement changes made.
NOTE:
The Hello Time cannot be longer than the Max. Age. Otherwise, a
configuration error will occur. Observe the following formulas when setting
the above parameters:
Max. Age
≤ 2 x (For
ward Delay - 1 second)
Max. Age
≥ 2 x (Hello Time + 1 second)
