The causes and consequences of MAC address drift flapping

One, what is the MAC address flapping?

MAC address drift refers to a change in the interface of the MAC Address table entry within the same VLAN.

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Ii. Causes of production

1, because the loop or VRRP switch, resulting in the MAC address drift alarm. (No attention)

2, because the wireless user roaming, causing the MAC address drift alarm. (no attention)

3, the server double NIC binding problem.

4, virus, broadcast storm will also cause the MAC address offset .

Third, MAC address drift caused by the impact

1, the Internet speed is slow, there is a serious loss of packet phenomenon

2. Communication congestion within the LAN

Iv. How to determine if there is a MAC address drift phenomenon

1, when turning on the MAC address drift alarm switch, through the command display Trapbuffer view the alarm cache information, determine whether there is MAC address drift on the device.

2, through the command display mac-address flapping record to see the last one months of MAC address drift information. The recorded information includes: The start time and end time of the MAC address Drift, the VLAN and Mac where the MAC address drift occurs, the number of drift ports and drift.

3, through the command dis mac-address dynamic (Drift MAC address), see the interface between two ports to jump.

Five, how to eliminate MAC address drift alarm information

The first type: Manually shutdown the interface where the drift occurs.

Advantages: The simplest and most reliable

Disadvantage: The flow of the entire interface will be interrupted by manual participation.

The second kind: automatically down the drift port by configuring the drift detection action on the interface as Error-dwon.

command: mac-address flapping trigger Error-down in interface mode

Advantages: Timely and fast, you can also restore the port by configuring the automatic recovery time timing.

Disadvantage: the flow of the entire interface will be interrupted.

The Third Kind: by configuring the Drift detection action on the interface as Quit-vlan, the Drift interface is specified to exit within the VLAN domain, which eliminates the MAC address drift and breaks the loop.

< Span style= "Font-family:arial, ' the song Body '; Line-height:20.390625px;text-indent:-28px;background-color:rgb (255,255,255);" >                   command: mac-address flapping trigger Quit-vlan

in interface mode

< Span style= "Font-family:arial, ' the song Body '; Line-height:20.390625px;text-indent:-28px;background-color:rgb (255,255,255);" > < Span style= "Font-family:arial, ' the song Body '; Line-height:20.390625px;text-indent:-50px;background-color:rgb (255,255,255);" >                  Pros: Only the VLAN domains that exist in the loop will be resolved without interrupting traffic from other normal VLAN domains.

< Span style= "Font-family:arial, ' the song Body '; Line-height:20.390625px;text-indent:-28px;background-color:rgb (255,255,255);" > < Span style= "Font-family:arial, ' the song Body '; Line-height:20.390625px;text-indent:-50px;background-color:rgb (255,255,255);" >                  Cons: Specifies that during the aging cycle, only one interface can be exited from the VLAN. If there are multiple loops, the broken ring is slower.

Fourth: All configuration Spanning Tree protocol, STP or MSTP.

This article is from the "Wolffang's Technology Hut" blog, so be sure to keep this source http://381552138.blog.51cto.com/7833981/1653292

The causes and consequences of MAC address drift flapping