Configuring Flush Interval

Configuration of a flush interval allows enabling or disabling flush optimization, which is based upon the flush interval value. The configuration is applicable per switch (context) basis.

1. Configure a flush interval value for a default switch as 200 cs (20 centi-seconds).

   Type the following:

   iS5comm# configure terminal

   iS5comm(config)# spanning-tree flush-interval 20

   iS5comm(config)#end

   • View the spanning tree information by executing the following show command.

   iS5comm# show spanning-tree detail

   MST00 is executing the mstp compatible Multiple Spanning Tree Protocol

   Bridge Identifier has Priority 32768, Address 00:01:02:03:04:01

   Configured  Max age 20 sec 0 cs,  Forward delay 15 sec 0 cs

   Configured Hello Time 2 sec 0 cs

   Dynamic Path Cost Disabled

   Flush Interval  20 centi-sec, Flush Invocations 0

   Flush Indication threshold 0

   We are root of the spanning tree

   Current Root has priority 32768, address  00:01:02:03:04:01

   cost of root path is 0

   Number of Topology Changes 0, Time since topology Change 0 seconds ago

   Transmit Hold-Count 3

   Root Times : Max age 20 sec 0 cs     Forward delay 15 sec 0 cs

   Port 1 [Gi0/1] of MST00 is Designated, Forwarding

   Gi0/1 is operating in the MSTP Mode

   Port path cost  200000, Port priority  128,

   Port Identifier  128.1. Port HelloTime  2 sec 0 cs,

   bpdu-receive enabled

   Loop Guard is disabled

2. Configuring flush interval value for default switch as default value (0).

   Type the following:

   iS5comm# configure terminal

   iS5comm(config)# spanning-tree flush-interval 20 

   iS5comm(config)# no spanning-tree flush-interval

   iS5comm(config)#end

   • View the spanning tree information by executing the following show command.

   iS5comm# show spanning-tree detail

   In Switch A

   MST00 is executing the mstp compatible Multiple Spanning Tree Protocol

   Bridge Identifier has Priority 32768, Address 00:01:02:03:04:01

   Configured  Max age 20 sec 0 cs,  Forward delay 15 sec 0 cs

   Configured Hello Time 2 sec 0 cs

   Dynamic Path Cost Disabled

   Flush Interval 20 centi-sec, Flush Invocations 0

   Flush Indication threshold 0

   We are root of the spanning tree

   Current Root has priority 32768, address  00:01:02:03:04:01

   cost of root path is 0

   Number of Topology Changes 0, Time since topology Change 0 seconds ago

   Transmit Hold-Count 3

   Root Times : Max age 20 sec 0 cs     Forward delay 15 sec 0 cs

   Port 1 [Gi0/1] of MST00 is Designated, Forwarding

   Gi0/1 is operating in the MSTP Mode

   Port path cost  200000, Port priority  128,

   Port Identifier  128.1. Port HelloTime  2 sec 0 cs,

   bpdu-receive enabled

   Loop Guard is disabled

3. Configuring flush interval value for MSTI-1 in “default” switch as.

   Type the following:

   iS5comm# configure terminal

   iS5comm(config)# spanning-tree mst configuration

   iS5comm(config-mst)# instance 1 vlan 2

   iS5comm(config- mst)# end

   iS5comm(config)# spanning-tree flush-interval 20 

   iS5comm(config)# spanning-tree mst 1 flush-indication-threshold 2

   iS5comm(config)# no spanning-tree flush-interval

   iS5comm(config)#end

   • View the spanning tree information by executing the following show command.

   iS5comm# show spanning-tree detail

   MST00 is executing the mstp compatible Multiple Spanning Tree Protocol

   Bridge Identifier has Priority 32768, Address 00:01:02:03:04:01

   Configured  Max age 20 sec 0 cs,  Forward delay 15 sec 0 cs

   Configured Hello Time 2 sec 0 cs

   Dynamic Path Cost Disabled

   Flush Interval 20 centi-sec, Flush Invocations 0

   Flush Indication threshold 0

   We are root of the spanning tree

    ..................................

   bpdu-receive enabled

   Loop Guard is disabled

   MST01 is executing mstp compatible spanning-tree protocol

   Flush Invocations 0

   Flush Indication threshold 2

   .......................

   Operational Forward delay 15 sec 0 cs, Max age 20 sec 0 cs

   Number of Transitions to forwarding State : 0

   BPDUs : sent 6, received 0

4. Configuring flush interval value for MSTI-1 in a default switch as default value (0).

   Type the following:

   iS5comm# configure terminal

   iS5comm(config)# spanning-tree flush-interval 20 

   iS5comm(config)# no spanning-tree mst 1 flush-indication-threshold

   iS5comm(config-mst)# end

   • View the spanning tree information by executing the following show command.

   iS5comm# show spanning-tree detail

   MST00 is executing the mstp compatible Multiple Spanning Tree Protocol

   Bridge Identifier has Priority 32768, Address 00:01:02:03:04:01

   Configured  Max age 20 sec 0 cs,  Forward delay 15 sec 0 cs

   Configured Hello Time 2 sec 0 cs

   Dynamic Path Cost Disabled

   Flush Interval 20 centi-sec, Flush Invocations 0

   Flush Indication threshold 0

   We are root of the spanning tree

    ..................................

   bpdu-receive enabled

   Loop Guard is disabled

   MST01 is executing mstp compatible spanning-tree protocol

   Flush Invocations 0

   Flush Indication threshold 0

   .......................

   Operational Forward delay 15 sec 0 cs, Max age 20 sec 0 cs

   Number of Transitions to forwarding State : 0

   BPDUs : sent 6, received 0