viii
About MSTP ························································································································· 281
MSTP features ················································································································ 281
MSTP protocol frames ······································································································ 282
Basic concepts in MSTP ··································································································· 283
How MSTP works ············································································································ 286
MSTP implementation on devices ······················································································· 287
Rapid transition mechanism ····································································································· 287
Edge port rapid transition ·································································································· 287
Root port rapid transition ··································································································· 288
P/A transition ·················································································································· 288
Protocols and standards ·········································································································· 290
Configuring spanning tree protocols ················································· 291
Restrictions and guidelines: spanning tree protocol configuration ····················································· 291
Restrictions: Compatibility with other features ········································································ 291
Restrictions: Interface configuration ····················································································· 291
Spanning tree protocol tasks at a glance ····················································································· 292
STP tasks at a glance ······································································································ 292
RSTP tasks at a glance ···································································································· 293
PVST tasks at a glance ···································································································· 294
MSTP tasks at a glance ···································································································· 295
Setting the spanning tree mode ································································································· 296
Configuring an MST region ······································································································ 297
Configuring the root bridge or a secondary root bridge ··································································· 298
Restrictions and guidelines ································································································ 298
Configuring the device as the root bridge of a spanning tree ····················································· 298
Configuring the device as a secondary root bridge of a spanning tree ········································· 298
Configuring the device priority ··································································································· 299
Configuring the maximum hops of an MST region ········································································· 299
Configuring the network diameter of a switched network································································· 300
Setting spanning tree timers ····································································································· 300
Setting the timeout factor ········································································································· 302
Configuring the BPDU transmission rate ····················································································· 302
Configuring edge ports ············································································································ 303
Configuring path costs of ports ·································································································· 303
About path cost ··············································································································· 303
Specifying a standard for the default path cost calculation ························································ 303
Configuring path costs of ports ··························································································· 306
Configuring the port priority ······································································································ 306
Configuring the port link type ···································································································· 307
Configuring the mode a port uses to recognize and send MSTP frames ············································· 308
Enabling outputting port state transition information ······································································· 308
Enabling the spanning tree feature ···························································································· 309
Restrictions and guidelines ································································································ 309
Enabling the spanning tree feature in STP/RSTP/MSTP mode ·················································· 309
Enabling the spanning tree feature in PVST mode ·································································· 309
Performing mCheck ················································································································ 310
About mCheck ················································································································ 310
Restrictions and guidelines ································································································ 310
Performing mCheck globally ······························································································ 310
Performing mCheck in interface view ··················································································· 310
Disabling inconsistent PVID protection ······················································································· 311
Configuring Digest Snooping ···································································································· 311
Configuring No Agreement Check ····························································································· 312
Configuring TC Snooping ········································································································· 314
Configuring protection features ································································································· 315
Spanning tree protection tasks at a glance ············································································ 315
Configuring BPDU guard ··································································································· 315
Enabling root guard ········································································································· 316
Enabling loop guard ········································································································· 317
Configuring port role restriction ··························································································· 318
Configuring TC-BPDU transmission restriction ······································································· 318