Controller 'x.x.x.x"detected duplicate Ip address x.x.x.x

[cisconell]

Hi ,

I get this error on my controller

Controller 'x.x.x.x"detected duplicate Ip address x.x.x.x being used by machine with mac address aa:bb:cc:dd:ee:ff:gg

But When I check this mac aa:bb:cc:dd:ee:ff:gg it has a differenet ip assoicated.

I have only one link beteen controller and switch .

Please let me know if some one has come across something simlar

Thanks

[Amjad Abdullah]

Hi,

It is possible that when the issue happens the client get informed and s/he changes the ip address (if it has a static one for example).

I would suggest to prevent users from using static ip addresses (by enabling DHCP required in WLAN config -> advanced tab).

If the issue persists please check if it is repeated with only one client or with multiple clients to troubleshoot further.

Regards,

Amjad

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[cisconell]

on each alram I see its reporting with different mac address , for sure its not because some one is configuring same static ip address

[Amjad Abdullah]

Make sure then your DHCP does not provide IP addresses that are already reserved.

If using more than one DHCP servers, make sure the scopes are not overlapping.

HTH

Amjad

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[marstoyanoff]

I had a similar issue. I agree with Ajaad. Things to check:

++ alternative dhcp server on the same vlan;

++ dhcp scope - excluded range;

Cheers,

Marty

[cisconell]

I have verifed this and all okay

Make sure then your DHCP does not provide IP addresses that are already reserved.

If using more than one DHCP servers, make sure the scopes are not overlapping.

To me its looks some communication problem between the controllers

Thanks

[Scott Fella]

So you have more than one WLC? Does the WLC have the same vlans defined and is the user being put in the same vlan when roaming?

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[smayanja123]

Try to disable LAG mode on next reboot. This is under controller.

Let me know if that works for you.

Sam

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[Scott Fella]

The only time I ever see that is when I have had a duplicate address in the network. If you are not experiencing any issues then I wouldn't worry about it but if your users experience poor performance then I would investigate more and see if maybe there is a static address on a device.

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[cisconell]

Thanks Scott,

There is no performance issue reported so far, only thing noticed the controller goes red in WCS monitoring saying not reachable ,even though i can ping the controller and everything is okay,

Suspecting this could be realated to the duplicate ip alarm.

[cisconell]

Sam,

I can try that , and let you know .