One of the most mysterious errors you’ll see when working with DirectAccess are related to failures in IP-HTTPS connectivity. I did a blog post on this problem last year and you can find it at http://blogs.technet.com/b/tomshinder/archive/2010/03/30/troubleshooting-the-no-usable-certificate-s-ip-https-client-error.aspx
Phillip Sand clued me into another possible cause of IP-HTTPS connectivity problems. First, whenever you suspect a problem with IP-HTTPS connectivity, you should run the command:
netsh interface httpstunnel show interface
If you see the following:
Role : client
URL : https://da.domain.com:443/IPHTTPS
Last Error Code : 0x103
Interface Status : no usable certificate(s) found
Where da.domain.com is the FQDN used to connect to the IP-HTTPS listener on the external interface of the UAG DirectAccess server, then you know you have a problem.
In addition to the cause I mentioned in the earlier blog post is a situation related to the CA certificate not being installed in the NTAUTH store of the UAG DirectAccess server. You can find out if the CA certificate is installed by running the command:
certutil –v –store –enterprise ntauth
on the UAG DirectAccess server. If everything is OK, then you’ll see something like what appears in the figure below (this is what you’ll see if you’re using the UAG DirectAccess Test Lab Guide for your UAG DA lab):
If you don’t see any certificate listed, then that can cause the 0x103 error on the client.
You can fix the problem by running the command:
certutil –addstore –enterprise –ntauth IssuingCACert.cer
Where IssusingCACert.cert is the root CA certificate.
Hat tip to Philipp Sand for this great info!
Principal Knowledge Engineer, Microsoft DAIP iX/Identity Management
Anywhere Access Group (AAG)
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