Cisco Pm-4-err_disable Loopback Error Detected
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SwitchingSpanning Tree ProtocolTroubleshoot and AlertsConfiguration Example and TechNotes Errdisable Port State Recovery on the Cisco IOS Platforms Download Print pm-4-err_disable link-flap error detected Available Languages Download Options PDF (143.8 KB) View with Adobe Reader
%ethcntr-3-loop_back_detected: Loop-back Detected
on a variety of devices ePub (82.1 KB) View in various apps on iPhone, iPad, Android, Sony pm-4-err_disable bpduguard error detected Reader, or Windows Phone Mobi (Kindle) (87.6 KB) View on Kindle device or Kindle app on multiple devices Updated:Mar 23, 2016 Document ID:69980 ContentsIntroductionPrerequisitesRequirementsComponents UsedBackground InformationPlatforms That
Pm-4-err_disable Channel-misconfig (stp) Error Detected
Use ErrdisableErrdisableFunction of ErrdisableCauses of ErrdisableDetermine If Ports Are in the Errdisabled StateDetermine the Reason for the Errdisabled State (Console Messages, Syslog, and the show errdisable recovery Command)Recover a Port from Errdisabled StateCorrect the Root ProblemReenable the Errdisabled PortsVerifyTroubleshootRelated Information Introduction This document defines the errdisabled state, describes how to recover from it, and provides examples %ethcntr-3-half_dux_collision_exceed_threshold of errdisable recovery. This document uses the terms errdisable and error disable interchangeably. Customers often contact Cisco Technical Support when they notice that one or more of their switch ports have become error disabled, which means that the ports have a status of errdisabled. These customers want to know why the error disablement happened and how they can restore the ports to normal. Note: The port status of err-disabled displays in the output of the show interfaces interface_number status command. Prerequisites Requirements There are no specific requirements for this document. Components Used In order to create the examples in this document, you need two Cisco Catalyst 4500/6500 Series Switches (or the equivalent) in a lab environment with cleared configurations. The switches should run Cisco IOSĀ® Software and each switch should have two Fast Ethernet ports that are capable of EtherChannel and PortFast. The information in this document was created from the devices in a specific lab environment. All of the devices used in this document star
to find this is in the output of show interfaces status. A switch port can end be error
Cisco Disable Keepalive
disabled if the software (IOS or CatOS) detects an error
Errdisable Recovery
situation on the port. The port is effectively shut down until re-enabled manually or automatically if a ethcntr-3-loop_back_detected loop-back detected on gigabitethernet recovery timer is specified for the error condition. One such error condition results from the existence of a loopback on the port. The switch sends keepalive packets http://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/69980-errdisable-recovery.html out all interfaces. If a keepalive packet is received on the same interface it was sent from, then a loop exists that has not been blocked by Spanning-Tree Protocol. If this occurs, these messages are generated (these specific messages are from a Cisco Catalyst 2940). %ETHCNTR-3-LOOP_BACK_DETECTED: Keepalive packet loop-back detected on FastEthernet0/3.
%PM-4-ERR_DISABLE: loopback https://slaptijack.com/networking/err-disabled-loopback-edition/ error detected on Fa0/3, putting Fa0/3 in err-disable state
To resolve the problem, you must investigate the network beyond the port that is complaining and discover what sort of logical loop might exist that was undetectable by STP. Often, less capable devices (inexpensive unmanaged switches or hubs) are the culprit. Related Reading: Cisco Field Manual: Catalyst Switch Configuration by David Hucaby, Stephen McQuerry Building Cisco Multilayer Switched Networks by Richard Froom, Balaji Sivasubramanian, Erum Frahim Related Posts UDLD In Radio-Based Metro Ethernet Rings Cisco Catalyst 3560 POST Output Allowing DHCP Option 82 in Cisco DHCP Relay Agents Brand New ME3400G Can't Ping! 3 Reasons You Should Be Using Rapid Spanning Tree (802.1w) Get Slaptijack updates delivered to your Inbox or RSS Reader for free! CATEGORIES Graphics Design Information Systems IT Management Networking Programming Software System Administration Uncategorized Voice / Voice over IP ARCHIVES 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 © 2016 Slaptijack All Rights Reserved · Wordpress
2960 se Swtich on our LAN that is connected with another Cisco switch with trunk with crass cable. The backbone link is down frequtly since we have installed it on network follwing Eror has shown in log %ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected on GigabitEthernet0/2.Can somebody help http://blog.qsolved.com/2010/05/pm-4-errdisable-loopback-error-detected.html us resolve the issue?Do check for the faulty cable, once you connect with a new cable http://showipprotocols.blogspot.com/2008/01/loopback-detected-port-went-error.html then enable the ports on both the switches.A loopback error occurs when the keepalive packet is looped back to the port that sent the keepalive. The switch sends keepalives out all the interfaces by default. A device can loop the packets back to the source interface, which usually occurs because there is a logical loop in the network that the spanning tree has not blocked. error detected The source interface receives the keepalive packet that it sent out, and the switch disables the interface (errdisable). This message occurs because the keepalive packet is looped back to the port that sent the keepalive:Keepalives are sent on all interfaces by default in Cisco IOS Software Release 12.1EA-based software. In Cisco IOS Software Release 12.2SE-based software and later, keepalives are not sent by default on fiber and uplink interfaces. The suggested workaround is to disable keepalives and upgrade to Cisco IOS Software cisco pm-4-err_disable loopback Release 12.2SE or later.Please click here for more details on Errisable Port State Recovery on the Cisco IOS Platforms.Citation - This blog post does not reflect original content from the author. Rather it summarizes content that are relevant to the topic from different sources in the web. The sources might include any online discussion boards, forums, websites and others. Posted by Info at 9:52 AM Email This BlogThis! Share to Twitter Share to Facebook Labels: %ETHCNTR-3-LOOP_BACK_DETECTED , Cisco 2960 No comments : Post a Comment Newer Post Older Post Home Subscribe to: Post Comments ( Atom ) What is Qsolved? QSolved is a online tech support marketplace that helps you ask, collaborate and resolve your tech support issues with certified Cisco experts around the world. No Contracts required First 3 question are free 100% refund if you are not satisfied. Visit us at www.qsolved.com Ask a Cisco expert Become a fan - Don't miss updates on Cisco's prodcuts Qsolved.com on Facebook Blog Archive ► 2014 ( 79 ) ► April ( 11 ) ► March ( 27 ) ► February ( 17 ) ► January ( 24 ) ► 2013 ( 61 ) ► December ( 8 ) ► November ( 11 ) ► October ( 8 ) ► September ( 4 ) ► August ( 2 ) ► June ( 3 ) ► May ( 7 ) ► April ( 9 ) ► March ( 6 ) ► February ( 3 ) υ
2008 Loopback detected, port went error-disabled suddenly Email ThisBlogThis!Share to TwitterShare to FacebookShare to Pinterest One working switch port on my Cisco Catalyst 2950 suddenly went down by itself! Of course, my phone rang when I was having dinner, and then I had to tell my colleagues how to do a port reset step by step. Luckily, after the port reset, the port went back on. I did not pay much attention to this event, until it happened to the same port again! This time, I drilled in to check the log, and found something suspicious: .Jan 30 10:12:25: %ETHCNTR-3-HALF_DUX_COLLISION_EXCEED_THRESHOLD: Half-duplex loopback detected, collision threshold exceeded on FastEthernet0/24. .Jan 30 10:12:25: %PM-4-ERR_DISABLE: loopback error detected on Fa0/24, putting Fa0/24 in err-disable state .Jan 30 10:12:26: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/24, changed state to down .Jan 30 10:12:27: %LINK-3-UPDOWN: Interface FastEthernet0/24, changed state to down After my survey on Cisco.com, I found a workaround to this: just disable keepalive on that interface: Switch # config t Switch (config)# int f0/24 Switch (config-if)# no keepalive I believe that it is a software caveat. The phrase mentioned on the web page is: ..... The suggested workaround is to disable keepalives and upgrade to Cisco IOS Software Release 12.2SE or later. ..... References: Errdisable Port State Recovery on the Cisco IOS Platforms Do you like this post? You really should consider Subscribing by Email! Email ThisBlogThis!Share to TwitterShare to FacebookShare to Pinterest Tweet Posted by Li-Ji Hong at 5:24 PM Reactions: Location: Wanhua District, Taipei City, Taiwan No comments: Post a Comment Tip: you can also anonymously comment here. Newer Post Older Post Home Subscribe to: Post Comments (Atom) Popular Posts BGP sample practice, in the new Packet Tracer 5.3 I created this practice to test the Packet Tracer 5.3 features of BGP. Dual Stack IPv6 and IPv4 configuration (CNA-04-006) CCNA Exploration 4.0, Semester 4, "Dual Stack IPv6 and IPv4 configuration " Packet Tracer 5.0 practice file (CNA-04-006). ... Loopback detected, port went error-disabled suddenly One working switch port on my Cisco Catalyst 2950 suddenly went down by itself! Of course, my phone rang when I was having dinner, and the... How to remove VTP domain string: 2 reloads To restore a IOS switch to a "whole new" state, it is necessary to clear even the "VTP domain" string to null. I though