Error-disabled state
An error-disabled state is a switch-port state in which the device disables the port after detecting a configured error or protection violation.
Acing the CCNA Exam: Volume 2 Advanced Networking and Security
An error-disabled port is a switch port that has been administratively disabled by the device because a configured protection condition was triggered.
- How it is used
- Protects switch ports from excessive power draw and excessive DHCP traffic by stopping affected interfaces.
- How deep it goes
- Explains triggers, shutdown effects, Cisco IOS commands, logging, and manual or automatic recovery.
- Examples
- Uses excessive PoE consumption and a one-packet-per-second DHCP rate limit as operational failure examples.
- What you can do after
- Diagnose and recover protected Cisco switch ports using logs, shutdown/no shutdown, and ErrDisable Recovery.
Acing the CCNA Exam: Volume 1 Fundamentals and Protocols
An error-disabled state is a Cisco switch-port state in which the port is administratively and operationally disabled because of a detected error or protection violation.
- How it is used
- Protects the spanning-tree topology by disabling a PortFast-enabled port that receives a BPDU.
- How deep it goes
- Explains the trigger, down/down status, corrective sequence, and shutdown/no shutdown recovery procedure.
- Examples
- Uses Cisco CLI configuration, BPDU Guard error messages, and show ip interface brief status.
- What you can do after
- Diagnose a BPDU Guard shutdown, correct the connection, and restore the port with shutdown and no shutdown.
Read how Acing the CCNA Exam: Volume 1 Fundamentals and Protocols explains error-disabled state →
Related concepts
- BPDU Guardproduced by · BPDU Guard is a switch-port protection feature that error-disables a port when it receives a Spanning Tree Protocol Bridge Protocol Data Unit.
- statekind of · State is information or a configuration describing the condition of a system, entity, or computation at a particular time and potentially influencing subsequent behavior or decisions.
- port securityused by · Port security is a network-switch control that restricts a switch port to authorized device addresses or connection conditions and defines responses to violations.
- dynamic arp inspection rate limitingproduced by · Dynamic ARP Inspection rate limiting is a technique that restricts the rate of ARP messages received on a switch port.
- ip dhcp snooping limit rate rateproduced by · ip dhcp snooping limit rate rate is a Cisco IOS interface command that configures a DHCP message rate limit in packets per second.
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