iii
Basic concepts in RSTP ····································································································· 69
How RSTP works ·············································································································· 69
RSTP BPDU processing ····································································································· 70
PVST ···································································································································· 70
PVST protocol frames ········································································································ 70
Basic concepts in PVST······································································································ 71
How PVST works ·············································································································· 71
MSTP···································································································································· 71
MSTP features·················································································································· 71
MSTP protocol frames········································································································ 72
MSTP basic concepts········································································································· 73
How MSTP works·············································································································· 76
MSTP implementation on devices ························································································· 77
Rapid transition mechanism································································································· 77
Protocols and standards ············································································································ 80
Spanning tree configuration task lists ··························································································· 80
STP configuration task list ··································································································· 81
RSTP configuration task list································································································· 81
PVST configuration task list ································································································· 82
MSTP configuration task list ································································································ 83
Setting the spanning tree mode··································································································· 83
Configuring an MST region ········································································································ 84
Configuring the root bridge or a secondary root bridge ····································································· 85
Configuring the device as the root bridge of a specific spanning tree ············································ 85
Configuring the device as a secondary root bridge of a specific spanning tree ································ 86
Configuring the device priority····································································································· 86
Configuring the maximum hops of an MST region ··········································································· 86
Configuring the network diameter of a switched network··································································· 87
Setting spanning tree timers ······································································································· 87
Configuration restrictions and guidelines ················································································ 88
Configuration procedure ····································································································· 88
Setting the timeout factor ··········································································································· 89
Configuring the BPDU transmission rate ······················································································· 89
Configuring edge ports ·············································································································· 90
Configuration restrictions and guidelines ················································································ 90
Configuration procedure ····································································································· 90
Configuring path costs of ports···································································································· 90
Specifying a standard for the device to use when it calculates the default path cost ························· 91
Configuring path costs of ports ····························································································· 93
Configuration example········································································································ 93
Configuring the port priority ········································································································ 94
Configuring the port link type ······································································································ 94
Configuration restrictions and guidelines ················································································ 94
Configuration procedure ····································································································· 95
Configuring the mode a port uses to recognize and send MSTP frames··············································· 95
Enabling outputting port state transition information········································································· 96
Enabling the spanning tree feature ······························································································ 96
Enabling the spanning tree feature in STP/RSTP/MSTP mode···················································· 96
Enabling the spanning tree feature in PVST mode···································································· 96
Performing mCheck·················································································································· 97
Configuration restrictions and guidelines ················································································ 97
Performing mCheck globally ································································································ 97
Performing mCheck in interface view ····················································································· 97
Disabling inconsistent PVID protection ························································································· 98
Configuring Digest Snooping ······································································································ 98
Configuration restrictions and guidelines ················································································ 99
Configuration procedure ····································································································· 99
Digest Snooping configuration example ················································································· 99
Configuring No Agreement Check ····························································································· 100
Configuration prerequisites································································································ 101
Configuration procedure ··································································································· 102
No Agreement Check configuration example ········································································· 102
