Chapter 11 Spanning Tree Protocol

 

Table 29 MRSTP: Configuration (continued)

 

 

 

 

LABEL

DESCRIPTION

 

 

 

 

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 24 on page 104 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.

 

 

 

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 103 for more information on MRSTP.

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

 

111

GS-3012/GS-3012F User’s Guide