802.1d STP, , , , 50 ( +BPDU )。 RSTP , 、 , 。
, PC , , STP , 。 , , , STP 。 Port Fast 。
, 。 portfast , :
1、 :( )
SNC(config)#int f0/1 // SNC(config-if)#spanning-tree portfast // portfast SNC(config-if)#spanning-tree portfast disabled // portfast 2、 :( , )
SNC(config)#spanning-tree portfast default // portfast SNC(config)#no spanning-tree portfast default // portfast
: HUB portfast ? HUB ? , , HUB。
, HUB STP , HUB portfast 。 Bpduguard 。Bpduguard BPDU Error-Disabled 。
, STP , STP, BPDU。 Bpduguard , , BPDU , PC STP, BPDU。 ,
BPDU , BPDU GUARD Error-Disabled , , , , 。
SNC(config)#int f0/1 //
SNC(config-if)#spanning-tree bpduguard enabled // bpduguard
SNC(config-if)#spanning-tree bpduguard disabled // bpduguard
bpduguard , 。
。 , 。 , , ,
。 , , :
:
SNC#conf t SNC(config)#errdisable recovery
cisco3550 :
SNC#conf t SNC(config)#errdisable recovery cause ? // all Enable timer to recover from all causes bpduguard Enable timer to recover from BPDU Guard error disable state channel-misconfig Enable timer to recover from channel misconfig disable state dhcp-rate-limit Enable timer to recover from dhcp-rate-limit error disable state dtp-flap Enable timer to recover from dtp-flap error disable state gbic-invalid Enable timer to recover from invalid GBIC error disable state l2ptguard Enable timer to recover from l2protocol-tunnel error disable state link-flap Enable timer to recover from link-flap error disable state loopback Enable timer to recover from loopback detected disable state pagp-flap Enable timer to recover from pagp-flap error disable state psecure-violation Enable timer to recover from psecure violation disable state security-violation Enable timer to recover from 802.1x violation disable state udld Enable timer to recover from udld error disable state unicast-flood Enable timer to recover from unicast flood disable state vmps Enable timer to recover from vmps shutdown error disable state SNC(config)#errdisable recovery cause loopback
IOS , !
* : ( )