Users Guide

1 Ensure that the interfaces are in L2 mode.
2 Globally enable RSTP.
NOTE: Whenever a port becomes a designated port, it will start a timer called the edge delay while timer (hello-time + 1/2 *
hello-time); if the hello-time is set to 2 seconds, the edge delay while timer is 3 seconds. If BPDUs are not received for 3
seconds, then the port is declared as oper edge on the y and is moved to forwarding state.
Enable globally
RSTP enables STP on all physical and port-channel interfaces which are in L2 mode to automatically include the interfaces as part of the
RSTP topology. Only one path from a bridge to any other bridge is enabled. Bridges block a redundant path by disabling one of the link
ports.
• Congure Spanning-Tree mode to RSTP in CONFIGURATION mode.
spanning-tree mode rstp
• Disable RSTP globally for all L2 interfaces in CONFIGURATION mode.
spanning-tree disable
• Remove an interface from the RSTP topology in INTERFACE mode.
spanning-tree disable
• Re-enable an interface in INTERFACE mode.
no spanning-tree disable
• Re-enable RSTP globally for all L2 interfaces in CONFIGURATION mode.
no spanning-tree disable
View all port participating in RSTP
OS10# show spanning-tree
Spanning tree enabled protocol rstp with force-version rstp
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 32768, Address 3417.4455.667f
Root Bridge hello time 2, max age 20, forward delay 15
Bridge ID Priority 32768, Address 90b1.1cf4.a523
Configured hello time 2, max age 20, forward delay 15
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
-----------------------------------------------------------------------------------
ethernet1/1/1 128.260 128 200000000 BLK 0 0 0000.0000.0000 0.0
ethernet1/1/2 128.264 128 200000000 BLK 0 0 0000.0000.0000 0.0
ethernet1/1/3 128.268 128 200000000 BLK 0 0 0000.0000.0000 0.0
416
Layer 2