Pm-4-err_disable Loopback Error Detected On
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SwitchingSpanning Tree ProtocolTroubleshoot and AlertsConfiguration Example and TechNotes Errdisable Port State Recovery on the Cisco IOS Platforms Download Print Available Languages Download Options PDF (143.8 KB) View with Adobe Reader on pm-4-err_disable link-flap error detected a variety of devices ePub (82.1 KB) View in various apps on iPhone,
Pm-4-err_disable Bpduguard Error Detected
iPad, Android, Sony Reader, or Windows Phone Mobi (Kindle) (87.6 KB) View on Kindle device or Kindle app on multiple devices %ethcntr-3-loop_back_detected: loop-back detected Updated:Mar 23, 2016 Document ID:69980 ContentsIntroductionPrerequisitesRequirementsComponents UsedBackground InformationPlatforms That 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
Pm-4-err_disable Channel-misconfig (stp) Error Detected
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 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 %ethcntr-3-half_dux_collision_exceed_threshold 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 started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command. Background Information Platforms That Use Errdisable The errdisable feature is supported on these Catalyst switches: Catalyst switches that run Cisco IOS Software: 2900XL / 3500XL 2940 / 2950 / 2960 / 2970 3550 / 3560 / 3560-E / 3750 / 3750-E 4000 / 4500 6000 / 6500 Catalyst switches that run Cataly
to find this is in the output of show interfaces status. A switch port can end be error
Disable Keepalives In Cisco Switch
disabled if the software (IOS or CatOS) detects an error
Cscea46385
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 http://blog.qsolved.com/2010/05/pm-4-errdisable-loopback-error-detected.html on network follwing Eror has shown in log %ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected on GigabitEthernet0/2.Can somebody help us resolve the issue?Do check for the faulty cable, once you connect with a new cable then enable the http://www.techexams.net/forums/ccnp/46455-loop_back_detected-some-help.html 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 error detected 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. 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 pm-4-err_disable loopback error 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 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 prodc
to this Thread… rakem Senior Member Join Date May 2005 Location Sydney, Australia Posts 805 Certifications CCNA, CCNP, CCIE#38186(R&S), JNCIA-JUNOS, JNCIS-SEC, JNCIP-SEC, JNCIS-ENT, F50-531, F50-533 09-07-200911:23 PM #1 Loop_back_detected - Some help. Not an exam question here but im sure I can get some good advise here.. Today a college hooked up a new switch into our network. It was a 3560 being connected to a pair of 3750s in a stack, so one uplink went to Gi1/0/18 and the other went to Gi2/0/18. When the second cable (Cat6) was connected a bunch of our switches went down. The uplink ports went into err-disabled and the error in the log was: %ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected on GigabitEthernet0/48. %PM-4-ERR_DISABLE: loopback error detected on Gi0/48, putting Gi0/48 in err-disable state Now the expected behaviour was for spanning tree to just block the second connection to Gi2/0/18 and for no outage at all. In the end about 10 switches went down with the loopback error. So I have been researching the loopback error and found this link: http://www.cisco.com/application/pdf...e_recovery.pdf Which says: "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. 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 fibre and uplink interfaces. For more information, refer to Cisco bug ID CSCea46385" So i have a few que