Verify that your network is set up correctly and meets connectivity prerequisites for upgrading vCenter Server.

For information on creating a PTR record, see the documentation for your vCenter Server host operating system.

For information about configuring Active Directory, see the Microsoft Web site.

Domain users that are part of a Windows Administrators group with vCenter Server Administrator permission cannot be used to authenticate vCenter Server during upgrade and do not have vCenter Server permission after upgrade.


  1. Verify that the fully qualified domain name (FQDN) of the system where you will upgrade vCenter Server is resolvable. To verify that the FQDN is resolvable, type nslookup -nosearch -nodefname your_vCenter_Server_fqdn at a command-line prompt.
    If the FQDN is resolvable, the nslookup command returns the IP and name of the domain controller machine.
  2. Verify that DNS reverse lookup returns a fully qualified domain name when queried with the IP address of the vCenter Server.
    When you upgrade vCenter Server, the installation of the web server component that supports the vSphere Web Client fails if the installer cannot look up the fully qualified domain name of the vCenter Server from its IP address.
    Reverse lookup is implemented by using PTR records.
  3. If you use DHCP instead of a manually assigned (static) IP address for vCenter Server, make sure that the vCenter Server computer name is updated in the domain name service (DNS). Test the update by pinging the computer name.
    For example, if the computer name is, run the following command at the Windows command prompt:
    If you can ping the computer name, the name is updated in DNS.
  4. Ensure that the ESXi host management interface has a valid DNS resolution from the vCenter Server and all instances of vSphere Web Client. Ensure that the vCenter Server has a valid DNS resolution from all ESXi hosts and all instances of vSphere Web Client.
  5. If you intend to use Active Directory as an identity source, verify that it is set up correctly. The DNS of the vCenter Single Sign-On Server host machine must contain both lookup and reverse lookup entries for the domain controller of the Active Directory.
    For example, pinging should return the domain controller IP address for mycompany. Similarly, the ping -a command for that IP address should return the domain controller host name.
    Avoid trying to correct name resolution issues by editing the hosts file. Instead, make sure that the DNS server is correctly set up.
  6. Before the upgrade, select the domain user to use for upgrading vCenter Server. Give that domain user exclusive administrator permission for vCenter Server, not as part of a Windows Administrators group.


Your network is ready for vCenter Server upgrade.

What to do next

Prepare other components of your environment.