> Source: [sk122532](https://support.checkpoint.com/results/sk/sk122532)

# sk122532 - VPN is failing with error "encryption failure: Tunnel failure, unresolved SA (VPN Error code 01)"

| Property | Value |
|----------|-------|
| Solution ID | sk122532 |
| Date Created | 2018-03-26 |
| Last Modified | 2020-12-16 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R81 (EOS) |

## Symptoms

- VPN fails to establish with the error message: "encryption failure: Tunnel failure, unresolved SA (VPN Error code 01)"

## Cause

The MSPI_by_methods table is full due to large amount of IPSec SA negotiations.

## Solution

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

---

# Agent Instructions

This content is from the Check Point Support Center (https://support.checkpoint.com), the official knowledge base for Check Point cybersecurity products.

## Navigating This Knowledge Base

- **Complete index**: [llms.txt](https://support.checkpoint.com/llms.txt)
- **All SK articles**: [SecureKnowledge Sitemap](https://support.checkpoint.com/sitemaps/secureknowledge-sitemap-index.xml)
- **SK article URL pattern**: `https://support.checkpoint.com/results/sk/{skId}`
- **Markdown responses**: AI bot User-Agents automatically receive `text/markdown` content