Chapter 13 Spanning Tree Protocol

Table 36 Advanced Application > Spanning Tree Protocol > MRSTP (continued)

LABEL

DESCRIPTION

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.

 

 

Edge

Select this check box to configure a port as an edge port when it is directly attached to a

 

computer. An edge port changes its initial STP port state from blocking state to forwarding

 

state immediately without going through listening and learning states right after the port

 

is configured as an edge port or when its link status changes.

 

Note: An edge port becomes a non-edge port as soon as it receives a Bridge Protocol Data

 

Unit (BPDU).

 

 

Priority

Configure the priority for each port here.

 

Priority decides which port should be disabled when more than one port forms a loop in

 

the 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 that you assign this value according to the speed of the bridge. The slower

 

the media, the higher the cost - see Table 31 on page 124 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.

 

 

13.7 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 13.1 on page 124 for more information on MRSTP.

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ES3500 Series User’s Guide