> Source: [sk115128](https://support.checkpoint.com/results/sk/sk115128)

# sk115128 - "UNSUPPORTED-EXCHANGE-TYPE" error message from Check Point gateway when IKE negotiation fails

| Property | Value |
|----------|-------|
| Solution ID | sk115128 |
| Date Created | 2016-12-22 |
| Last Modified | 2017-04-23 |
| Technical Level | Advanced |
| OS | Gaia |

## Symptoms

- * "UNSUPPORTED-EXCHANGE-TYPE" error message from Check Point gateway when IKE negotiation fails.  

  ![](https://sc1.checkpoint.com/sc/SolutionsStatics/sk115128/11612260049.png)
* In the IKE logs, there might be a message stating that no IKE packets (MM 1-6) were exchanged. The Check Point gateway initiates the error message with no prior IKE packet from the peer.
* The "UNSUPPORTED-EXCHANGE-TYPE" message is sent from the Check Point gateway every 30 seconds.

## Cause

The peer gateway is configured to initiate the IKE negotiation in Aggressive mode, whereas the Check Point gateway is not.

## Solution

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

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