Spanning-Tree Feature configure

Conf. Optional Spanning-Tree Feature
////////////////////////////////////////////
Basis
{
 PortFast;
 {
  1:If u enable voice VLAN feature,the PortFast is automatically enabled;when u disable
    voice VLAN,the Portfast feature isnt automatically disabled.
  2:PVST+,R-PVST+,MSTP;
 }

 BPDU Guard;
 {
  spanning-tree portfast bpduguard default;
  Note:Spanning tree shutdown the PortFast-operation state interface;
       BPDU guard feature puts the interface in the error-disabled state;
 
  interface xxx;
  spanning-tree bpduguard enable;
  Note:it is put in the error-disabled state when the interface receive a BPDU;
  
  Caution:
  1:BPDU guard feature provides a secure respone to invalid conf. casue u must manually put
    the interface back in service;
 }
 
 BPDU Filtering
 {
  spanning-tree portfast bpdufilter default;
  Note:Prevent interface that in PortFast-operation state from sending and receive BPDUs;
       BPDU is received on Portfast-enabled interface,the interface lose the Portfast-oper-
       ation status,and BPDU filtering is diasbled;
  
  interface xxx;
  spanning-tree bpdufilter enable;
  Note:Prevent from sending and receiving BPDU;
 }

 UplinkFast
 {
  Note:Only supported by PVST+;
  1:if a switch looses connectivity,it begins using the alternate path as soon as the
    spanning-tree selects a new root port;by enabling UplinkFast with the spanning-tree
    iplinkfast global conf. command,u can  accelerate the choice of a new root port when
    a link or switch fails;it transition the port to forwarding status without listening
    & learning;
  2:Uplinkfast is most useful in wiring-closet switch at the access or edge of the network,
    it isnt appropriate for backbone devices.
 }
 
 Backbone
 {
  1:Backbonefast detects indirect failures in the core of the backbone,is a complementary
    to uplinkfast feature;
  2:only supported by PVST+;
  
  3:operation
  {
   what does the switch do when fails:
   1:inferior BPDU received on a blocked interface, the root port and other blocked
     interfaces on the switch become alternate path to the root switch;
   2:inferior BPDU received on a root port,all blocked interfaces become alternate
     path to the root switch;
   3:inferior BPDU received on a root port without any blocked interfaces,the switch
     assumes that it has lost connectivity to the root switch;cause maximum aging
     time on the root prot to expire,and becoming the root switch;
   4:if a switch has alternate path to the root switch,it send a root link query
     request.the switch sends the RLQ request on all alternate path and waits for
     reply from them;
 
   what is the result after changing:
   1:if the switch discovers that it still has an alternate path to the root,it
     expires the maximum aging time on the interface that received inferior BPDU;
   2:if all alternate paths indicate that the switch lost the connectivity to the
     switch,the switch expires the maximun aging time on the interface that received
     the RLQ reply;
   3:if one and more alternate path can still connect to the root switch,the switch
     makes all interfaces on which it received an inferior BPDU its designated ports
     and moves them from blocking state,through the listening,learning,into the
     forwarding state;
  }
 }
 Root Guard
 {
  1:Switch in MST-mode,root guard forces the interface to be a designated port;
  2:if boundary port is blocked in IST instance because of root guard,the interface also
    is blocked in all MST instance;
  3:Root guard enabled on an interface applies to all the VLANs to which the interface
    belongs,VLAN can be grouped and mapped to an MST instance;
  4:u can enable this feature in PVST+,Rapid PVST+,MSTP mode;
 }
 
 Loop Guard
 {
  1:loop can use loop guard to prevent alternate or root ports from becoming designated
    ports because of a failure that leads to a unidirectional link;
  2:remmond to use on the entire switched network;
  3:Loop guard prevent alternate and root port from becoming designated port,and doesnt
    send BPDUs on these port;
  4:can be enabled on PVST+,R-PVST+,MSTP;
  5:In MST mode,BPDUs arent sent on nonboundary ports only if the interface is blocked
    by loop guard in all MST instance.On boundary port,loop guard locks the interface in
    all MST instance;
 }  
}

/////////////////////////////////////////////
Configuration
{
  Default conf.
 {
  Port Fast,BPDU filtering,BPDU guard: Globally disabled;
  Uplinkfast:Globally disabled;
  Backbonefast:Globally disabled;
  Root guard:Globally disabled;
  Loop guard:Globally disabled;
 }

 Enable Portfast
 {
  spanning-tree portfast default;
  intface xxx;
  spanning-tree portfast [trunk];
  show spanning-tree interface xxx portfast;
  spanning-tree portfast disable; 
 }
 
 Enable BPDU Guard
 {
  conf t;
  spanning-tree portfast bpduguard default;
  interface xxx;
  spanning-tree portfast;

  no spanning-tree portfast bpduguard default;
  spanning-tree bpduguard enable;
  //this command can override the setting of the global conf.;
 }

 BPDU Filtering
 {
  conf t;
  spanning-tree portfast bpdufilter default;
  intface xxx;
  spanning-tree portfast;

  no spanning-tree portfast bpdufilter default;
  spanning-tree bpdufilter enable;
  //this command can override the setting of the globle conf.;
 }
 
 Uplinkfast
 {
  CAUTION:uplinkfast cannot be enabled on VLANs that have been configured with a switch
          priority;
  conf t;
  no spannning-tree vlan xxx priority;
  spanning-tree uplinkfast [max-update-rate xxx];//0 to 32000,default is 150;
 }

 Backbonefast
 {
  conf t;
  spanning-tree backbonefast;
 }
 
 Root Guard
 {
  caution:
  U cannot conf the root guard & portfast on the same interface;
  U cannot conf root guard & loop guard at the same time;

  conf t;
  interface xxx;
  spanning-tree guard root;
 }

 Loop Guard
 {
  CAUTION:make sure this port is alternate & root port;
  show spanning-tree active;
  show spanning-tree mst;
  conf t;
  spanning-tree loopguard default;

  no spanning-tree loopguard default;
  intface xxx;
  spanning-tree guard loop;
 }

 Display the Spanning-tree Status
 {
  show spanning-tree active;
  show spanning-tree detail;
  show spanning-tree interface xxx;
  show spanning-tree mst interface xxx;
  show spanning-tree summary [totals];
  clear spanning-tree interface xxx;
  show spanning-tree;
 }