| Event Id | 20 |
| Source | Microsoft-Windows-OnlineResponderWebProxy |
| Description | The Online Responder Service detected an invalid configuration for the %1 property. The value was changed from %2 to %3. |
| Event Information | According to Microsoft : Cause : This event is logged when the Online Responder Service detected an invalid configuration for the property. Resolution : Correct the configuration of the Online Responder Web proxy The property that contained the invalid value should be identified in the corresponding error message. Investigate the property and, if necessary, replace it with a valid value. This error indicates that configuration values are not within the permitted range. This can occur if the registry was manually modified. Verify An Online Responder serves as an intermediary between clients that need to check certificate validity and a certification authority (CA) that issues certificates and certificate revocation lists (CRLs). To verify that the Online Responder service is functioning properly, you need to isolate the Online Responder and client from the CA and any CRL distribution points to confirm that revocation checking continues to take place and that revocation data is originating only from the Online Responder. The best way to confirm this scenario is to complete the following steps that involve the CA, the client, CRL distribution points, and the Online Responder: Issue new certificates. Revoke a certificate. Publish a CRL. Remove CRL distribution point extensions from the issuing CA. Confirm that client computers can still obtain revocation data. To perform these procedures, you must be a member of local Administrators on the computer hosting the Online Responder and on the client computer, and you must have Manage CA permissions on the computer hosting the CA, or you must have been delegated the appropriate authority. Issue new certificates To issue new certificates: 1.On the computer hosting the CA, click Start, point to Administrative Tools, and then click Certification Authority. 2.Configure several certificate templates to autoenroll certificates for a computer running Windows Vista or Windows XP Professional. 3.When information about the new certificates has been published to Active Directory domain controllers, open a command prompt window on the client computer and enter the following command to start certificate autoenrollment: certutil -pulse. 4.On the client computer, use the Certificates snap-in to confirm that the certificates have been issued to the user and to the computer, as appropriate. If they have not been issued, repeat step 2. You can also stop and restart the client computer to initiate certificate autoenrollment. Revoke a certificate To revoke a certificate: 1.On the computer hosting the CA, click Start, point to Administrative Tools, and then click Certification Authority. 2.In the console tree, click Issued Certificates, and then select the certificate you want to revoke. 3.On the Action menu, point to All Tasks, and then click Revoke Certificate. 4.Select the reason for revoking the certificate, and click Yes Publish a CRL To publish a CRL: 1.On the computer hosting the CA, click Start, point to Administrative Tools, and then click Certification Authority. 2.In the console tree, click Revoked Certificates. 3.On the Action menu, point to All Tasks, and then click Publish. Remove all CRL distribution point extensions from the issuing CA To remove all CRL distribution point extensions from the issuing CA: 1.On the computer hosting the CA, click Start, point to Administrative Tools, and then click Certification Authority. 2.Select the CA. 3.On the Action menu, click Properties. 4.On the Extensions tab, confirm that Select extension is set to CRL Distribution Point (CDP). 5.Click any CRL distribution points that are listed, click Remove, and click OK. 6.Stop and restart the CA. 7.Configure a new certificate template, and complete autoenrollment again. Confirm that client computers can obtain revocation data To confirm that client computers can obtain revocation data: 1.Click Startmmc, and then press ENTER. 2.If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue. 3.On the File menu, click Add/Remove Snap-in, click Certificates, and then click Add. 4.Select the user or computer account to whom the certificate was issued, click Finish, and then click OK. 5.Open the Personal Certificates store, right-click the most recently issued certificate, point to All Tasks, and then click Export to start the Certificate Export Wizard. Export the certificate to a .cer file. 6.Open a command prompt window. 7.Type certutil -url 8.In the Verify and Retrieve dialog box that appears, click From CDP and From OCSP, and confirm that the revocation data is retrieved from the Online Responder and not from a CRL distribution point. |
| Reference Links | Event ID 20 from Source Microsoft-Windows-OnlineResponderWebProxy |
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