> Source: [sk92931](https://support.checkpoint.com/results/sk/sk92931)

# sk92931 - Gratuitous ARP sent by Check Point cluster in broadcast cause 3rd party device to notify about duplicate IP address and not to pass the traffic to this IP address

| Property | Value |
|----------|-------|
| Solution ID | sk92931 |
| Date Created | 2013-05-30 |
| Last Modified | 2021-12-27 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20 |

## Symptoms

- * 3rd party devices report duplicate IP addresses on the interfaces facing the Check Point cluster members and do not forward traffic to the Check Point cluster members.

* Traffic capture on cluster members shows the following:


  Check Point cluster member asks who has certain IP address.  

  3rd party device replies with an ARP Reply.  

  Check Point cluster member broadcasts the 3rd party devise's ARP reply.
* 3rd party device shows IP address conflict and "Duplicate IP detected on Network" warning.  
  Same errors may be seen in traffic capture (when opened in Wireshark).

  <br />

## Cause

This is caused by a duplicate IP address entries on the 3rd party device.  
The device had already learned the relevant information regarding this IP address, and the Gratuitous ARP packets are causing the 3rd party device to define this IP address as duplicate IP address.  
Therefore, they will not pass traffic to this IP address.

## Solution

This solution requires authentication. Please log in to view the full solution.

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