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How do I fix MAC address flapping?
You can do the following:
- Check the network switches for misconfigurations that might cause a data-forwarding loop.
- If you are not running spanning-tree, turn it on.
- To track down a loop, start with the following command: #show mac-address-table address [flapping mac]
Why is my tunnel flapping?
CAUSE: One of the reasons for the tunnel flapping or not passing traffic is if the SPI number is not stable. A software bug may be the issue, lifetime for phase 1 and phase 2 are not the same so rekey is happening. Proxy ID are mismatching so rekey is happening frequently.
What causes NIC flapping?
Route flapping is caused by pathological conditions (hardware errors, software errors, configuration errors, intermittent errors in communications links, unreliable connections, etc.) within the network which cause certain reachability information to be repeatedly advertised and withdrawn.
How do I stop MAC address flapping?
There are three methods of preventing MAC address flapping: Configure a static MAC address for an interface. Run the mac-address static mac-address interface-type interface-number { vlan vlan-id1 | vlanif vlan-id2 vsi vsi-name } command in the system view to create a static MAC address entry.
How to solve Mac flapping in Cisco switch?
01-31-2012 12:07 AM SO you get some packet looped from device with MAC 2c76.8aae.410e. You can see packet is coming both from Gi1/0/11 and Gi2/0/12. You need to trace that mac down to the end device and see why this packet taking both pathes to your switch.
Where does the Mac flapping between ports come from?
MAC 0800069 is a device from Siemens. I checked all cables going from each port which is mentioned and the port is dedicated to each device. Each device is connect with two networkcards. One card goes to vlan 137. One card goes to vlan 138. Still there is one host which is having the same mac.
What does Mac flapping in VLAN 1 mean?
%SW_MATM-4-MACFLAP_NOTIF: Host 2c76.8aae.410e in vlan 1 is flapping between port Gi1/0/11 and port Gi2/0/12 It is happening on a stacked switch… What’s this and how to solve it? For me, it looks like a device being connected or trying to get connected on two different switch ports (loop?!)… Kind regards and thanks. 01-31-2012 12:07 AM
How to fix Mac flapping on a server?
I recommend you change one of the ports of that Blade to another switch where you can configure a etherchannel with them (stack switches, same switch). says that the server is using the links in active/active configuration. To avoid to confuse the lan switch you need to use bundles of ports.