Cisco WS-C2980G-A Software Guide - Page 140
Configuring Spanning Tree Timers, Configuring the Hello Time
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Configuring Spanning Tree Timers Chapter 7 Configuring Spanning Tree Configuring Spanning Tree Timers Spanning tree timers affect the spanning tree performance. You can configure the spanning tree timers for a VLAN in PVST+ or an MISTP instance in MISTP mode. If you do not specify a VLAN when the switch is in PVST+ mode, VLAN 1 is assumed. If you do not specify an MISTP instance when the switch is in MISTP mode, MISTP instance 1 is assumed. Caution Exercise care using these commands. For most situations, we recommend that you use the set spantree root and set spantree root secondary commands to modify the spanning tree performance parameters. Table 7-6 describes the switch variables that affect spanning tree performance. Table 7-6 Switch Variable Descriptions Variable Hello Time Maximum Age Timer Forward Delay Timer Description Default Determines how often the switch broadcasts its Hello message to 20 sec other switches. Measures the age of the received protocol information recorded for a port and ensures that this information is discarded when its age limit exceeds the value of the maximum age parameter recorded by the switch. The timeout value is the maximum age parameter of the switches. 2 sec Monitors the time spent by a port in learning and listening states. 15 sec The timeout value is the forward delay parameter of the switches. Configuring the Hello Time Enter the set spantree hello command to change the Hello time for a VLAN or for an MISTP instance. The possible range for interval is from 1-10 seconds. To configure the spanning tree bridge Hello time for a VLAN or an MISTP instance, perform this task in privileged mode: Step 1 Step 2 Task Configure the Hello time for a VLAN or MISTP instance. Verify the configuration. Command set spantree hello interval [vlan] mistp-instance [instances] show spantree [vlan | mistp-instance instances] This example shows how to configure the spanning tree Hello time for VLAN 100 to 7 seconds: Console> (enable) set spantree hello 7 100 Spantree 100 hello time set to 7 seconds. Console> (enable) This example shows how to set the spantree Hello time for an instance to 3 seconds: Console> (enable) set spantree hello 3 mistp-instance 1 Spantree 1 hello time set to 3 seconds. Console> (enable) 7-44 Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide-Release 8.1 78-15486-01
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