HSRP duplicate logs, all from APPLE MAC addresses

Unanswered Question
Jul 19th, 2010


Over the past few months, we have been getting more and more HSRP duplicate messages in which APPLE MAC addresses are the conflictor.  Any thoughts on why only Apple devices are doing this?

sample message

Jul 19 14:39:00: %HSRP-4-DUPADDR: Duplicate address x.x.x.x on Vlanxxx, sourced by 0023.32xx.xxxx.

I have this problem too.
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Giuseppe Larosa Mon, 07/19/2010 - 13:46

Hello Joe,

a possible explanation could be a misunderstanding of DHCP reply from server taking the gateway ip address (the HSRP VIP) as the address the device should have.

Are you using DHCP to dynamically assign IP addresses in the affected Vlans/IP Subnets?

Hope to help


randomjoe1 Mon, 07/19/2010 - 14:49

I work on a campus sized network with over 50,000 active unique wired MAC addresses.  we have hundreds of VLANS that serve DHCP.  The VLAN interfaces are off a baseline config, HSRP is properly set up, the helper address is correct, and the issues are happenning not just on different VLANs, but different HSRP buddy pairs.

I have 9 unique MAC addresses that are causing the issue, all of which are Apple.  Our end users use many different platforms and only Apple's are producing this issue.  The error always is the Apple MAC dupping an HSRP secondary, not the standby.  Our DHCP pools do not include the address range of the routing interfaces.

Giuseppe Larosa Wed, 07/21/2010 - 13:02

Hello Joe,

no problem! 

sometimes specially for strange cases or for threads with little information in initial post someone has to put very basic questions just to start the discussion I knew I was not giving you a solution, but just a way to ask you to describe your network scenario.

from the link you have found:

"When a Sleep Proxy sees an IPv4 ARP or IPv6 ND Request for one of the sleeping device's addresses, it answers on behalf of the sleeping device, without waking it up, giving its own MAC address as the current (temporary) owner of that address."[2]

This may appear confusing to network administrators who are not expecting the behaviour of changing MAC addresses.

I agree this can be the root cause of your issue with these few Apple devices.

Hope to help


plwalsh Wed, 02/19/2014 - 04:11

Feb 2014

I'm getting the same logs for a VLAN served by a HSRP pair of 6509s. The wired connection of two Apple iMacs are triggering the logs. One iMac is 'Sharing' its wired ethernet connection via an Apple Airport (a wireless access point). We've disabled the 'Sharing' feature and are waiting to see if the HSRP DUPADDR messages re-occur.


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