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
:
Sweep range of sizes
:
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
:
Sweep range of sizes
:
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