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| Chapter 11 Spanning Tree Protocol |
| Table 25 Advanced Application > Spanning Tree Protocol > RSTP (continued) | |
| LABEL | DESCRIPTION |
| Hello Time | This is the time interval in seconds between BPDU (Bridge Protocol Data Units) |
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| configuration message generations by the root switch. The allowed range is 1 to |
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| 10 seconds. |
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| Max Age | This is the maximum time (in seconds) the Switch can wait without receiving a |
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| BPDU before attempting to reconfigure. All Switch ports (except for designated |
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| ports) should receive BPDUs at regular intervals. Any port that ages out STP |
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| information (provided in the last BPDU) becomes the designated port for the |
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| attached LAN. If it is a root port, a new root port is selected from among the Switch |
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| ports attached to the network. The allowed range is 6 to 40 seconds. |
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| Forwarding Delay | This is the maximum time (in seconds) the Switch will wait before changing states. |
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| This delay is required because every switch must receive information about |
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| topology changes before it starts to forward frames. In addition, each port needs |
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| time to listen for conflicting information that would make it return to a blocking |
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| state; otherwise, temporary data loops might result. The allowed range is 4 to 30 |
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| seconds. |
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| As a general rule: |
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| Note: 2 * (Forward Delay - 1) >= Max Age >= 2 * (Hello Time + 1) |
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| Port | This field displays the port number. |
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| * | Settings in this row apply to all ports. |
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| Use this row only if you want to make some settings the same for all ports. Use this |
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| row first to set the common settings and then make adjustments on a |
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| basis. |
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| Note: Changes in this row are copied to all the ports as soon as you |
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| make them. |
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| Active | Select this check box to activate RSTP on this port. |
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| Priority | Configure the priority for each port here. |
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| Priority decides which port should be disabled when more than one port forms a |
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| loop in a switch. Ports with a higher priority numeric value are disabled first. The |
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| allowed range is between 0 and 255 and the default value is 128. |
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| Path Cost | Path cost is the cost of transmitting a frame on to a LAN through that port. It is |
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| recommended to assign this value according to the speed of the bridge. The |
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| slower the media, the higher the cost - see Table 22 on page 100 for more |
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| information. |
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| Apply | Click Apply to save your changes to the Switch’s |
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| loses these changes if it is turned off or loses power, so use the Save link on the |
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| top navigation panel to save your changes to the |
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| are done configuring. |
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| Cancel | Click Cancel to begin configuring this screen afresh. |
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11.5 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 RSTP.
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