Troubleshooting/Monitoring Certificates-based IPSEC

Hi,

Could someone tell me how I can monitor and troubleshoot certificate-based IPCSEC. I did the labs explaining the deployment of IPSEC between DNS client et server. See link below :

http://technet.microsoft.com/en-us/library/ee649268%28v=ws.10%29.aspx

I completed the configuration. But, unfortunately, I have no idea of making sure IPSEC is working fine when it is configured by GPO and AD CS certificates. And, how to eventually troubleshoot it ?

Thanks in adavance for any help !