Chapter 11 Spanning Tree Protocol

Table 27 Advanced Application > Spanning Tree Protocol > MRSTP (continued)

LABEL

DESCRIPTION

Max Age

This is the maximum time (in seconds) the 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) the 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

 

recommended to assign this value according to the speed of the bridge. The

 

slower the media, the higher the cost - see Table 22 on page 100 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 begin configuring this screen afresh.

11.7 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 99 for more information on MRSTP.

"This screen is only available after you activate MRSTP on the Switch.

110

 

GS-3012/GS-3012F User’s Guide