Portfast & Uplinkfast

 

 

sw1# show spanning-tree brief

VLAN1
  Spanning tree enabled protocol ieee
  Root ID    Priority    32768
             Address     cc00.0394.0000
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32768
             Address     cc00.0394.0000
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface                                   Designated
Name                 Port ID Prio Cost  Sts Cost  Bridge ID            Port ID
-------------------- ------- ---- ----- --- ----- -------------------- -------

FastEthernet0/8      128.9    128    19 FWD     0 32768 cc00.0394.0000 128.9 

FastEthernet0/9      128.10   128    19 FWD     0 32768 cc00.0394.0000 128.10

 

 

sw2#sh span br

VLAN1
  Spanning tree enabled protocol ieee
  Root ID    Priority    32768
             Address     cc00.0394.0000
             Cost        19
             Port        9 (FastEthernet0/8)
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

  Bridge ID  Priority    32768
             Address     cc00.082c.0000
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300

Interface                                   Designated
Name                 Port ID Prio Cost  Sts Cost  Bridge ID            Port ID
-------------------- ------- ---- ----- --- ----- -------------------- -------
FastEthernet0/8      128.9    128    19 FWD     0 32768 cc00.0394.0000 128.9 
FastEthernet0/9      128.10   128    19 BLK     0 32768 cc00.0394.0000 128.10

 

1, portfast

在R3上使用扩展的PING命令

R3#ping
Protocol [ip]:
Target IP address: 10.1.1.1
Repeat count [5]: 1000
Datagram size [100]:
Timeout in seconds [2]:
Extended commands [n]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 1000, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!...................!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!...!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

在SW2的F0/3端口上启用PORTFAST前，

sw2(config)#int f 0/3

sw2(config)#shut

sw2(config)#no shut

上面黄色区域就是在关闭再启用F0/3端口后，R3PING通R1所用的时间间隔

在SW2的F0/3端口上启用PORTFAST

sw2(config-if)#spanning-tree portfast

sw2(config-if)#shut

sw2(config-if)#no shut

上面红色区域就是在关闭再启用F0/3端口后，R3PING通R1所用的时间间隔

 

 

2，UPLINKFAST

在R3上使用扩展的PING命令

R3#ping
Protocol [ip]:
Target IP address: 10.1.1.1
Repeat count [5]: 1000
Datagram size [100]:
Timeout in seconds [2]:
Extended commands [n]:
Sweep range of sizes [n]:
Type escape sequence to abort.
Sending 1000, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!...................!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!...!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

启用UPLINKFAST前

sw2(config)#int f 0/8

sw2(config-if)#shut

sw2(config)-if#no shut

上面的黄色区域表示在关闭再启用F0/8端口后，R3PING通R1所用的时间间隔

启用UPLINKFAST

sw2(config)#spanning-tree uplinkfast

sw2(config)#int f 0/8

sw2(config-if)#shut

sw2(config-if)#no shut

上面的红色区域表示在关闭再启用F0/8端口后，R3PING通R1所用的时间间隔

 

 

 

 

实验拓扑

 

本文出自 “穿过地狱去看海” 博客，谢绝转载！