Troubleshooting Desktop Access

Common issues and resolution steps.

Auto-login does not work

Smart Card Service Not Running

You connect to a Windows host from the Teleport UI, land on the Windows login screen and nothing happens.

You can click on the username, click Sign-in options and click on the smart card icon. The error message is: "No Valid Certificates Were Found on This Smart Card".

Solution: Enable the Smart Card Service

Usually, this means that the Smart Card service is not running on the target host.

First, make sure that you enable the Smart Card service in Group Policy.

If that doesn't help, log into the target host directly, open the "Services" program from the "Start" menu and check that the "Smart Card" service is in the "Running" state.

If the "Smart Card" service is not running, open PowerShell and run gpupdate.exe /force. This forces a Group Policy sync and should pick up the service changes.

Smart Card Certificate Not Trusted

You connect to a Windows host from the Teleport UI, land on the Windows login screen and see an error message: "The smartcard certificate used for authentication was not trusted" (or similar).

Solution: Import the Teleport CA

This means that the host does not trust the Teleport CA.

First, make sure that you import the Teleport CA into Group Policy. Note that if the Teleport CA was rotated since the last import, you will have to fetch the new CA using tctl auth export --type=windows >user-ca.cer

If that doesn't help, log into the target host directly, open PowerShell and run gpupdate.exe /force. This forces a Group Policy sync and should pick up the new CA.

New session "hangs"

Host Unreachable

You click CONNECT on a Windows host from the Teleport UI, a new tab opens but nothing is displayed other than the top bar. After a while, an error is displayed about a failed connection.

Solution: Open Firewall for RDP Traffic

This happens when the windows_desktop_service can't reach the target Windows host.

First, make sure that you open the RDP port and allow remote RDP connections in Group Policy.

If that does not help, check if the target host is online and try to ping it from the Linux server that runs windows_desktop_service. If the host is online but not reachable, there is some other networking barrier in the way, specific to your infrastructure.

Hostname Does Not Resolve

Connections to Windows Desktops hang during connection establishment, or the Teleport debug logs show errors of the form couldn't resolve winserver.example.com.

Solution: Ensure Firewall Permits DNS Traffic

For desktops that are automatically discovered via LDAP, Teleport makes DNS queries against the LDAP server in order to resolve the hostname to an IP address.

Ensure that your firewalls allow inbound DNS traffic on port 53 from the instance(s) running Teleport's Windows Desktop Service to the LDAP server (Active Directory Domain Controller).

Teleport fails to start

Invalid LDAP Credentials

Teleport fails to start with an error similar to:

LDAP Result Code 49 "Invalid Credentials": 80090308: LdapErr: DSID-0C0903C5, comment: AcceptSecurityContext error, data 52e, v2580\x00

Solution: Fix Credentials

This means that your LDAP username and password were not correct. Double-check them in the ldap section of windows_desktop_service.

Note that the LDAP username must be formatted as DOMAIN\User, where DOMAIN is the NetBIOS name for the domain. For example, user Administrator in domain example.com should be formatted as EXAMPLE\Administrator.

Incorrect Domain

Teleport fails to start with an error similar to:

LDAP Result Code 10 "Referral": 0000202B: RefErr: DSID-0310082F, data 0, 1 access points
"\tref 1: 'xample.com'"
"\x00"

Solution: Correct Domain

This means that your domain name is likely wrong. Double-check the domain field in the ldap section of windows_desktop_service.

Domain Controller Unreachable

Teleport fails to start with an error similar to:

LDAP Result Code 200 "Network Error": dial tcp ad.example.com:389: i/o timeout

Solution: Check LDAP Address

This means that your Domain Controller is down or unreachable. Double-check the addr field in the ldap section of windows_desktop_service. If it's correct, check that the Domain Controller is up and reachable from the server that runs windows_desktop_service.

Cannot Initialize LDAP over TLS

Teleport fails to connect to LDAP on startup. You may see errors similar to:

LDAP Result Code 52 "Unavailable": 00000000: LdapErr: DSID-0C090F78, comment: Error initializing SSL/TLS, data 0, v2580\x00

or

connecting to LDAP server: unable to read LDAP response packet: read tcp 172.18.0.5:35970->;172.18.0.4:636: read: connection reset by peer

Solution: Enable LDAPS

This means you do not have an LDAP certificate installed on your LDAP servers, or you are trying to make an insecure connection on port 389. Teleport requires secure LDAPS connections, which are typically on port 636. First, confirm that you are connecting to the correct LDAPS port. If that doesn't resolve your issue, you can instal Active Directory Certificate Services (AD CS) or import your own third party certificate. Note that Active Directory is extremely picky so take care to generate your certificates correctly.