Alcatel-Lucent OmniSwitch AOS Release 7 - Page 5

Contents
OmniSwitch AOS Release 7 Network Configuration Guide March 2011 3
Bridging VLANs Across Multiple Switches .................................................................4-11
Verifying the VLAN Configuration ..............................................................................4-13
Understanding Port Output .....................................................................................4-13
Chapter 5 Configuring Spanning Tree Parameters .............................................................5-1
In This Chapter ................................................................................................................5-2
Spanning Tree Specifications ..........................................................................................5-3
Spanning Tree Bridge Parameter Defaults .....................................................................5-4
Spanning Tree Port Parameter Defaults ..........................................................................5-4
Multiple Spanning Tree (MST) Region Defaults ............................................................5-5
Spanning Tree Overview .................................................................................................5-6
How the Spanning Tree Topology is Calculated .....................................................5-6
MST General Overview ................................................................................................5-12
How MSTP Works .................................................................................................5-12
Comparing MSTP with STP and RSTP .................................................................5-15
What is a Multiple Spanning Tree Instance (MSTI) ..............................................5-15
What is a Multiple Spanning Tree Region .............................................................5-16
What is the Common Spanning Tree .....................................................................5-17
What is the Internal Spanning Tree (IST) Instance ................................................5-17
What is the Common and Internal Spanning Tree Instance ...................................5-17
MST Configuration Overview ...............................................................................5-17
MST Interoperability and Migration ......................................................................5-18
Spanning Tree Operating Modes ..................................................................................5-20
Using Flat Spanning Tree Mode ............................................................................5-20
Using Per-VLAN Spanning Tree Mode .................................................................5-21
Using Per-VLAN Spanning Tree Mode with PVST+ ............................................5-22
OmniSwitch PVST+ Interoperability .....................................................................5-23
Using Spanning Tree Configuration Commands ..........................................................5-25
Configuring STP Bridge Parameters .............................................................................5-26
Selecting the Spantree Protocol ..............................................................................5-27
Configuring the Bridge Priority .............................................................................5-27
Configuring the Bridge Hello Time .......................................................................5-28
Configuring the Bridge Max-Age Time .................................................................5-29
Configuring the Forward Delay Time for the Switch ............................................5-29
Enabling/Disabling the VLAN BPDU Switching Status .......................................5-30
Configuring the Path Cost Mode ............................................................................5-31
Using Automatic VLAN Containment ...................................................................5-31
Configuring STP Port Parameters .................................................................................5-33
Enabling/Disabling Spanning Tree on a Port .........................................................5-34
Configuring Port Priority .......................................................................................5-36
Configuring Port Path Cost ....................................................................................5-37
Configuring Port Mode ..........................................................................................5-40
Configuring Port Connection Type ........................................................................5-41
Configuring the Edge Port Status ...........................................................................5-42
Restricting Port Roles (Root Guard) ......................................................................5-43
Restricting TCN Propagation .................................................................................5-43