Troubleshooting Of MAC Flapping For S7703 Highlighted

Latest reply: Dec 19, 2014 09:06:09 2739 2 0 0

eSight detect the phenomenon MAC Flapping in S7703

 

1.      MAC address flapping occurs in the following situations: a. Network cables of switches are connected incorrectly or switches use incorrect configurationsb. Unauthorized users simulate MAC address of valid network devices to attack the network. Firstly check the indicators. The indicators never flashing frequently. Secondly collect the information by the command display interface brief. The figure of InUti and OutUti is very low. Thirdly collect the information of Spanning Tree by the command display stp. The protocol of MSTP is enable the setting for the ports is appropriate. Eliminate the root cause is by the ring in the network.

2.      Check the information of display trapbuffe. The information about MAC Flapping is just as below:

#Oct 30 2014 14:28:02 S7703 L2IFPPI/4/MAC_FLAPPING_ALARM:OID 1.3.6.1.4.1.2011.5.25.42.2.1.7.12 The mac-address has flap value.  (L2IfPort=0,entPhysicalIndex=0,  BaseTrapSeverity=4, BaseTrapProbableCause=549, BaseTrapEventType=1,  MacAdd=1047-808a-e2f6,vlanid=99, FormerIfDescName=GigabitEthernet3/0/44, CurrentIfDescName=XGigabitEthernet1/0/0,DeviceName= S7703)

#Oct 30 2014 14:26:02 S7703 L2IFPPI/4/MAC_FLAPPING_ALARM:OID 1.3.6.1.4.1.2011.5.25.42.2.1.7.12 The mac-address has flap value.  (L2IfPort=0,entPhysicalIndex=0, BaseTrapSeverity=4, BaseTrapProbableCause=549, BaseTrapEventType=1,  MacAdd=1047-808a-e2f6,vlanid=99, FormerIfDescName=XGigabitEthernet1/0/0, CurrentIfDescName=GigabitEthernet3/0/44,DeviceName=SS7703)

From the information we found only the MAC Address 1047-808a-e2f6 flappingand the switch learned the MAC Address from the interface XGE1/0/0 & GE3/0/44.

3.      Confirm the MAC Address 1047-808a-e2f6 belong to which equipment by the command display arp | in 1047-808a-e2f6

<S7703>display arp | in 1047-808a-e2f6

IP ADDRESS      MAC ADDRESS     EXPIRE(M) TYPE        INTERFACE   VPN-INSTANCE

                                          VLAN/CEVLAN

------------------------------------------------------------------------------

10.0.99.44      1047-808a-e2f6  20        D-0/0       XGE1/0/0

10.0.99.45      1047-808a-e2f6  20        D-0/0       GE3/0/44

------------------------------------------------------------------------------

Total:326       Dynamic:305     Static:0     Interface:21    

4.      From the ARP mapping list, we can find the MAC Address of 1047-808a-e2f6 belong to IP Address 10.0.99.44 and 10.0.99.45. So the MAC addresses of two equipments are the same. Finally we found customer changed the MAC Address of one IA5000 this is the root cause.

Resume the MAC Address of IA5000 to the default value. Then the phenomenon of MAC Flapping disappear.

During the Troubleshooting, using different way to reduce the arrange of  possible root cause. That will be helpful for the work.

  • x
  • convention:

user_2790689
Created Dec 17, 2014 07:52:53 Helpful(0) Helpful(0)

Thank you.
  • x
  • convention:

w00228185
Created Dec 19, 2014 09:06:09 Helpful(0) Helpful(0)

you are welcme.

  • x
  • convention:

Reply

Reply
You need to log in to reply to the post Login | Register

Notice Notice: To protect the legitimate rights and interests of you, the community, and third parties, do not release content that may bring legal risks to all parties, including but are not limited to the following:
  • Politically sensitive content
  • Content concerning pornography, gambling, and drug abuse
  • Content that may disclose or infringe upon others ' commercial secrets, intellectual properties, including trade marks, copyrights, and patents, and personal privacy
Do not share your account and password with others. All operations performed using your account will be regarded as your own actions and all consequences arising therefrom will be borne by you. For details, see " Privacy."
If the attachment button is not available, update the Adobe Flash Player to the latest version!
Login and enjoy all the member benefits

Login and enjoy all the member benefits

Login