ZyXEL Communications ZyXEL Dimension ES-2108 User Manual

Page 105

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ES-2108 Series User’s Guide

Chapter 11 Spanning Tree Protocol

105

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 and the default value is 128.

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 22 on page 101

for more information.

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 25 Spanning Tree Protocol: Configuration (continued)

LABEL

DESCRIPTION

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