Verifying the network connectivity and port accessibility between the Tableau Server and the LDAP server The first step in troubleshooting integration issues between Tableau Server on Linux and an external LDAP server is to verify network connectivity and port accessibility. This includes ensuring that the necessary ports are open and that there are no network barriers preventing communication between the two servers. Option A is incorrect because changing the LDAP server's authentication model does not address potential connectivity issues. Option C is in-correct as reconfiguring user roles and permissions within Tableau Server is unrelated to LDAP integration issues. Option D is incorrect because installing additional security certificates on the LDAP server is unlikely to resolve a connectivity or integration issue.