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6 multiple rapid spanning tree protocol status – ZyXEL Communications GS-4012F/4024 User Manual

Page 106

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GS-4012F/4024 User’s Guide

Chapter 11 Spanning Tree Protocol

105

11.6 Multiple Rapid Spanning Tree Protocol Status

Click Advanced Application, Spanning Tree Protocol in the navigation panel to display the
status screen as shown next. See

Section 11.1 on page 97

for more information on MRSTP.

Note: This screen is only available after you activate MRSTP on the switch.

Max Age

This is the maximum time (in seconds) a switch can wait without receiving a BPDU

before attempting to reconfigure. All switch ports (except for designated ports)

should receive BPDUs at regular intervals. Any port that ages out STP information

(provided in the last BPDU) becomes the designated port for the attached LAN. If it

is a root port, a new root port is selected from among the switch ports attached to

the network. The allowed range is 6 to 40 seconds.

Forwarding Delay This is the maximum time (in seconds) a switch will wait before changing states.

This delay is required because every switch must receive information about

topology changes before it starts to forward frames. In addition, each port needs

time to listen for conflicting information that would make it return to a blocking state;

otherwise, temporary data loops might result. The allowed range is 4 to 30

seconds.
As a general rule:

Note: 2 * (Forward Delay - 1) >= Max Age >= 2 * (Hello Time + 1)

Port

This field displays the port number.

*

Settings in this row apply to all ports.
Use this row only if you want to make some settings the same for all ports. Use this

row first to set the common settings and then make adjustments on a port-by-port

basis.

Note: Changes in this row are copied to all the ports as soon as you

make them.

Active

Select this check box to activate STP on this port.

Priority

Configure the priority for each port here.
Priority decides which port should be disabled when more than one port forms a

loop in a switch. Ports with a higher priority numeric value are disabled first. The

allowed range is between 0 and 255.

Path Cost

Path cost is the cost of transmitting a frame on to a LAN through that port. It is

assigned according to the speed of the bridge. The slower the media, the higher

the cost - see

Table 21 on page 97

for more information.

Tree

Select which STP tree configuration this port should participate in.

Apply

Click Apply to save your changes to the switch’s run-time memory. The switch

loses these changes if it is turned off or loses power, so use the Save link on the

top navigation panel to save your changes to the non-volatile memory when you

are done configuring.

Cancel

Click Cancel to reset the fields.

Table 26 MRSTP: Configuration (continued)

LABEL

DESCRIPTION