anyone knows how to solve this problem ? i saw this problem for long time ago. but can not resolved :(
Jan 14 10:18:43.397: %C4K_EBM-4-HOSTFLAPPING: Host 00:0E:9B:53:44:1C in vlan 296 is flapping between port Fa2/2 and port
Information from CCO :
Error Message when the Host Address is a Source Address on Multiple Ports
The %C4K_EBM-4-HOSTFLAPPING:Host [mac-addr] in vlan [dec] is flapping between port [char] and port [char] error message appears.
This error message appears on the switch when the switch detects the specified host address as a source address on multiple ports.
The issue can occur due to Spanning Tree Protocol (STP) loops in the network that cause packet drops from the specific host. In addition to packet drops, STP loops lead to several other symptoms, which are listed here:
Loss of connectivity to, from, and through affected network regions.
High link utilization (often 100 percent).
High switch backplane utilization (compared to the baseline utilization).
Syslog messages that indicate packet looping in the network (for example, HSRP duplicate IP address messages).
Syslog messages that indicate constant address relearning or MAC address flapping messages.
An increase in the number of output drops on many interfaces.
Note: One or more of these symptoms independently can indicate different issues (or no issue at all). However, when you observe many of these symptoms at the same time, you must check whether a forwarding loop has developed in the network.
Enable spanning tree in order to prevent spanning tree loops. If you have disabled spanning tree, use the information in Spanning Tree Protocol Problems and Related Design Considerations to design your network without spanning tree loops.
so, what can i do with this ? i have checked the STP . looks ok but the logs still occur.
If you have a dual NIC server configured for load balancing you would experience this symptom. If this is the case you can configure an etherchannel on the switch side so both physical ports will be treated as a single logical port.
What is host 00:0E:9B:53:44:1C? Is it a wireless NIC? With access points it may be normal for MAC addresses to flap between the two. In which case you either just ignore the error messages or set your logging level higher.
sorry for the late reply, from your msg which means i just set the logging level higher will solved the issue ? and this was just an information only ? because, as i understand if this msg keep repeating it will causing high CPU utilization . kindly correctly me if you feel i am wrong.
thanks , and your reply will be highly appreciated.
you are probably getting this because you have a user roaming between two different access points so his mac address keeps wandering between 2 different switch ports . The message should not cause high cpu , make sure console logging is turned off in the switch . It will fill the logs up though .
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.