1、Minimizing Service Loss and Data Theft in a Campus Network,Preventing STP Forwarding Loops,Unidirectional Link Failure,Loop Guard,Root,Before Loop Guard,Root,With Loop Guard,如果使用loop guard，那么root guard将会被关闭。两者不能同时启用,UDLD and Loop Guard Configuration Commands,Configuring and verifying UDLD udld enabl
2、e show udld interface fa0/1 Configuring and verifying loop guard spantree global-default loopguard enable show spantree guard fa0/1,Configuring UDLD,Switch(config)#udld enable,Enables UDLD globally on all fiber-optic interfaces,Switch(config-if)#udld enable,Enables UDLD on an individual interface,Sw
3、itch(config-if)#no udld enable,Disables UDLD on an individual nonfiber-optic interface,Switch(config-if)#udld disable,Disables UDLD on an individual fiber-optic interface,Resetting and Verifying UDLD,Switch# udld reset,Resets all interfaces that have been shut down by UDLD,Switch#show udld interface
4、,Displays UDLD information for a specific interface,Configuring Loop Guard,Comparing Loop Guard and UDLD,Summary,UDLD detects and disables an interface with unidirectional connectivity, protecting the network from anomalous STP conditions. Loop guard detects and disables an interface with Layer 2 unidirectional connectivity, protecting the network from anomalous STP conditions. UDLD and loop guard are configured and verified using specific commands. Implementation of UDLD and loop guard protects spanning tree operations from being disrupted due to unidirectional links.,
