> Source: [sk36375](https://support.checkpoint.com/results/sk/sk36375)

# sk36375 - 'Encryption failure: Unknown SPI: 0xXXXX for UDP encapsulated IPsec packet' log appears repeatedly

| Property | Value |
|----------|-------|
| Solution ID | sk36375 |
| Date Created | 2008-11-25 |
| Last Modified | 2024-02-26 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R81.20, R81.10 (EOS) |

## Symptoms

- '`Encryption failure: Unknown SPI: 0xXXXXXXXX for UDP encapsulated IPsec packet`' log appears repeatedly.

## Cause

* In general, a single log may indicate that there was a missing SPI key to decrypt the packet.  

* Repeated logs may indicate that the relevant kernel tables are full and new VPN-related data cannot be recorded.   

  In this case, the VPN kernel debug (`# fw ctl debug -m VPN + queue warn err sas`) shows:   

  `queue_set_vals: Failed to set entry for queue `*QUEUE_KEY_ID*` on queue_table`  
  `make_ike2esp_queues: Failed to create IPSEC SA queues for IKE SA <0x`*YYY* `,0x`*ZZZ*`>`  
  `ike_esp_add_by_fields: ERROR: Failed to create new ike2esp record`  

* Duplicate object with the same IP of the Security Gateway or VS will also cause this issue. Symptoms typically occur after an upgrade of the management.

## Solution

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