> Source: [sk36718](https://support.checkpoint.com/results/sk/sk36718)

# sk36718 - VPN tunnel establishment fails with error message: "Phase one received notification from peer; payload malformed"

| Property | Value |
|----------|-------|
| Solution ID | sk36718 |
| Date Created | 2008-12-27 |
| Last Modified | 2023-12-18 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R81.20, R81.10 (EOS), R81 (EOS) |

## Symptoms

- * VPN tunnel establishment fails with error message: "Phase one received notification from peer; payload malformed"
* In IKE debug, phase 1 gets to packet 5 and There is no packet 6. The remote peer has initiated the tunnel, an INFO packet is sent to the remote peer after packet 5 stating PAYLOAD-MALFORMED.
* `$FWDIR\log\vpnd.elg` shows:  

  `[ vpnd pid][Date Time][] -- updatePayloadMap: received payload PA_ID.
  `  
  `[ vpnd pid][Date Time][] updatePayloadMap: offset (28) + payload length (48672) exceeds packet length (68)
  `  
  `[ vpnd pid][Date Time][] identifyPayloads: failed for phase 1 stage 5.
  `  
  `[ vpnd pid][Date Time][] decryptVerifyMessage: error in identifyPayloads`  
  `

  `

  `[ vpnd pid][Date Time][] MMProcess5: Failed to decrypt with pre-shared key`
  `

  `

  `[ vpnd pid][Date Time][] MMProcess5: End of PSK loop
  `  
  `[ vpnd pid][Date Time][] -- updatePayloadMap: received payload PA_ID.
  `  
  `[ vpnd pid][Date Time][] updatePayloadMap: offset (28) + payload length (48672) exceeds packet length (68)
  `  
  `[ vpnd pid][Date Time][] identifyPayloads: failed for phase 1 stage 5.
  `  
  `[ vpnd pid][Date Time][] MMProcess5: identifyPayloads failed.
  `  
  `[ vpnd pid][Date Time][] RespMMPacketError: error in FWIKE_EXCH_MAIN_MODE - FWIKE_MM_PACKET_5
  `  
  `[ vpnd pid][Date Time][] InitMMPacketError: possibly a preshared key mismatch`  
* Issue may occur after upgrade of the management server.

## Cause

The pre-shared key is not configured correctly on both peers.

## Solution

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