Stp Port Settings - D-Link DGS-3120-24TC Product Manual

xStack® DGS-3120 Series Managed Switch Web UI Reference Guide
NNI BPDU Address
Click the Apply button to accept the changes made for each individual section.
NOTE: The Bridge Hello Time cannot be longer than the Bridge Max Age. Otherwise, a configuration
error will occur. Observe the following formulas when setting the above parameters:
Bridge Max Age <= 2 x (Bridge Forward Delay - 1 second)
Bridge Max Age > 2 x (Bridge Hello Time + 1 second)

STP Port Settings

STP can be set up on a port per port basis.
To view the following window, click L2 Features > Spanning Tree > STP Port Settings, as show below:
It is advisable to define an STP Group to correspond to a VLAN group of ports.
The fields that can be configured are described below:
Parameter
Unit
From Port / To Port
External Cost
(0=Auto)
Used to determine the BPDU protocol address for GVRP in service provide site. It
can use 802.1d GVRP address, 802.1ad service provider GVRP address or a user
defined multicast address. The range of the user defined address is 0180C2000000
- 0180C2FFFFFF.
Figure 4–29 STP Port Settings window
Description
Select the unit you want to configure.
Select the starting and ending ports to be configured.
This defines a metric that indicates the relative cost of forwarding packets to the
specified port list. Port cost can be set automatically or as a metric value. The default
value is 0 (auto). Setting 0 for the external cost will automatically set the speed for
forwarding packets to the specified port(s) in the list for optimal efficiency. The default
port cost for a 100Mbps port is 200000 and the default port cost for a Gigabit port is
20000. Enter a value between 1 and 200000000 to determine the External Cost. The
lower the number, the greater the probability the port will be chosen to forward
packets.
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