> Source: [sk171907](https://support.checkpoint.com/results/sk/sk171907)

# sk171907 - Authentication of a Site-to-Site VPN connection with certificate does not work because the CRL check fails

| Property | Value |
|----------|-------|
| Solution ID | sk171907 |
| Date Created | 2021-02-08 |
| Last Modified | 2022-07-13 |
| Technical Level | General |
| Platform | 1500 |

## Symptoms

- * Authentication of a Site-to-Site VPN connection with certificate fails.

* VPN debug shows that CRL check against an external server failed:

  ```
  
  [sfwd xxxx] ExternalCrlFetchSingleton::asyncCallback: dp in front of queue: CN=xxxx,O=xxxx,C=xxxx
  [sfwd xxxx] ExternalCrlFetchSingleton::asyncCallback: calling cb_external with 0 asearch: 5e8b888
  [sfwd xxxx] fwFetchCRL_cb_external: fail
  [sfwd xxxx] fwFetchCRL_cb: begin
  [sfwd xxxx] fwFetchCRL_cb: Entering for dp: CN=xxxx,O=xxxx,C=xxxx
  [sfwd xxxx] fwFetchCRL_cb: Fetch failed
  [sfwd xxxx] ikeAuthExchange_r::validate_certs_state_handler: cert 0 is not valid. (Could not retrieve CRL.CN=xxxx,O=xxxx,C=xxxx).
  [sfwd xxxx] Exchange::setStatus: Changing status from: initial to: doomed (final)
  ```

## Solution

[Contact Check Point Support](https://www.checkpoint.com/support-services/contact-support/) to get a Hotfix for this issue.   
A Support Engineer will make sure the Hotfix is compatible with your environment before providing the Hotfix.   
For faster resolution and verification please collect [CPinfo](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92739) files from the Security Management and Security Gateways involved in the case.

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