D-Link DGS-1510-28XMP/ME [94/342] Stp port settings

DGS-1510/ME Series Metro Ethernet Switch Web UI Reference Guide

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)

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. The user may choose a time between 6 and 40 seconds. The default

value is 20 seconds.

Bridge Hello Time (1-2)

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. This field will only appear here when STP or RSTP is

selected for the STP Version. For MSTP, the Hello Time must be set on a port per

port basis. The default is 2 seconds.

Bridge Forward Delay (4-

30)

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.

The default is 15 seconds

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 BDPU 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

Used to determine the BPDU protocol address for STP in service provide site. It can

use 802.1D STP address or 802.1ad service provider STP 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. It is advisable to define an STP Group to correspond to a VLAN group of

ports.

To view the following window, click L2 Features > Spanning Tree > STP Port Settings as shown below: