How to Log into vCenter Server and Fix Some Login Errors

Wonder how to log in to vCenter Server, how to fix some common login errors? Keep reading to get the answer. You can also check vCenter login logs to secure virtual environment.


By Delia / Updated on February 17, 2023

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Log into vCenter Server to Manage ESXi Hosts Centrally

vCenter Server is advanced server management software that provides a centralized platform for controlling VMware vSphere environments. It enables you to pool and manage the resources of multiple hosts.

Generally, you can use vSphere Client to log in to vCenter Server and manage your vSphere inventory. Since the vSphere Client is automatically installed as part of the vCenter Server appliance deployment, it always points to the same vCenter Single Sign-On instance.

Next, I will introduce how to log into vCenter Server, and resolve some related issues.

vCenter Server 7

How to Log into vCenter Server Using vSphere Client

Next, I will provide a detailed guide for vCenter 7 login, as well as troubleshooting some common login issues.

1. Open a Web browser (Chrome, Firefox or Edge) and enter the URL for your vCenter Server instance.

Example: https://vcenter_server_ip_address_or_fqdn

2. If a warning message about a potential security risk appears, you can do the following to proceed:

🔹Chrome: Click Advanced to expand the description -> click Proceed to vcenter_server_ip_address_or_fqdn.

🔹Firefox: Click Advanced -> click Accept the Risk and Continue under the additional message.

🔹Edge: Click Details -> click Go on to the webpage under the additional message.

3. Then you will get to the Welcome page. Choose Launch vSphere Client (HTML5), and if the warning message appears again, repeat step 2.

launch vSphere Client (HTML5)

✍Note: For vSphere 7 and onward, the vSphere Client (HTML5) replaces the vSphere Web Client with the exact same functionality as the only client available for managing vSphere workflows.

4. Input the credentials of a user who has permissions on vCenter Server, and click Login.

login VMware SSO

The vSphere Client connects to all vCenter Server systems for which the specified user has permissions, allowing you to view and manage the vSphere inventory.

Default vCenter login name and password

Here’s the default password for vCenter (and some other VMware products) for your reference.




vCenter Appliance



vCenter Application



Discovery Manager



vCenter Chargeback



vSphere Data Protection



vSphere Data Protection Appliance



Fix: Cannot Log into vCenter Server Appliance

Many users encounter errors when logging into vCenter that prevent them from doing so properly. Here I will list some common login problems and briefly describe the solutions.

Login error “User name and password are required”

Some users receive “User name and password are required” while entering the username and password correctly.

user name and password are required

After making sure your login information is correct, you can first try clearing your browser cookies, refreshing the page, and trying to login again.

If this doesn’t work, consider checking the vCenter Certificate. Expired certificates can make vCenter inaccessible and cause other communication problems.

Check detailed solutions in vCenter Certificate Expired Cannot Login.

vCenter Certificate

Unable to log in with AD Domain Authentication

Sometimes when using Active Directory user name and password to log into vCenter Server component from the vSphere Client, the authentication fails.

invalid credentials

The reason, as VMware states, is that users can only use their user name and password to log in to the default domain. For other domains, they need to include the domain name (user@domain or DOMAIN\user).

For all vCenter SSO deployments, you can also change the default identity source, then users can log into default identity source with username and password only. Find more details in vCenter domain authentication not working.

vCenter login timeout

Some users cannot log into vCenter Server with the "Connection time out" error. The problem may be caused by the default authentication timeout value of the vSphere client. The default timeout value is 30 seconds - you can try changing it.

Launch vSphere Client, connect to another vCenter Server or ESXi host, then click Edit -> Client Settings > General. Select Use a custom value under the Client-Server Command Timeout, and enter a longer timeout value in seconds.

Where to Find Failed vCenter Login Logs

Virtualization technologies have many benefits, including easy scalability and better business continuity. However, virtual appliances can serve as entry points for malicious acts, so it’s necessary to check failed attempts to log into vCenter from time to time.

To do so, connect to vCenter via vSphere Client, click Monitor -> Tasks and Events > Events to see recent logs.

vCenter events

For login-related events, the Description field shows the username and IP address from which the connection was attempted; The target field lists where the login attempt was made to. If it is ESXi host, it will show the host name or IP address. If it appears as blank, then the login attempt was made to vCenter Server.

You can also use the filter to view specific events. For example, if you want to filter out failed login attempts, you can type "cannot login" in the Description field.

✍You can check for failed logins to your vCenter Server by the methods mentioned above, thus preventing malicious access. But there are more potential risks in a virtual environment than that, and backups are a common and necessary means to ensure data security.

Bonus Tips: Backup VMs Managed by vCenter Server Efficiently

After you add ESXi host to vCenter, you can manage respective virtual machines with advanced functions. However, there is no real VM backup solution (there’s only a file-based backup feature for VCSA configurations).

For virtual machines with more important data or business, you still need to use a dedicated VM backup solution for daily protection. Here I will use AOMEI Cyber Backup, the efficient VMware backup software designed to backup virtual machines securely and restore them from any point you need.

With it, you can add VMs managed by vCenter Servers or standalone ESXi hosts (including free ESXi) to a single console. Its simplicity makes it possible for even novices to configure ESXi or vCenter backups with several clicks.

AOMEI Cyber Backup can be installed on Windows and Linux systems, and works with VMware ESXi 6.0 and above versions (as well as Hyper-V servers). Here are some more benefits:

Backup in batch: Backup multiple VMs managed by vCenter Server or on a standalone ESXi host at once.
Hot backup: Backup VMware VMs while running. No need to suspend running operations and ongoing access.
Automation: Create VMware backup schedule to automate VM protection, with customizable retention policy.
Backup strategy: Perform full backup, or incremental/differential backup to track changed data resiliently.
Restore to new location: Perform in-place recovery, or restore a VM to new location in the same or another datastore/host/vCenter.
Email notification: Send email notification when the task is completed or abnormal.

You can click the following button to download the software.

Download Free TrialVMware ESXi & Hyper-V
Secure Download

How to back up virtual machines managed by vCenter

Here I will show you how to backup VMs managed by vCenter Server with AOMEI Cyber Backup in 3 simple steps

1. Navigate to Source Device > VMware > + Add VMware Device to add vCenter or Standalone ESXi host. And then click > Bind Device.

Add VMware ESXi host

2. Create backup task by hitting Backup Task > Create New Task. Follow the Wizard to schedule virtual machine backup. You can select as many VMs as you need to back them up at once.

Select virtual machines vCenter

  • Schedule daily/weekly/monthly VMware backup with different backup strategies, such as full backup for the entire VM and incremental backup for the changed data.
  • Set up backup cleanup to auto delete the old backup copies that exceed the retention period you specified.

3. Click Start Backup to execute (or just create) the task. Created backup tasks will be listed and monitored separately, for restoring, progress checking and schedule changing.

When restoring, you can also restore to new location to create a new VM in the same or another datastore/host/vCenter directly from the backup, saving the trouble of re-configuring the new VM.

Restore to new location


vCenter Server is an advanced service that can manage multiple ESXi hosts connected on a network. This article introduces how to log into vCenter Server, how to solve login errors, and how to check failed vCenter login logs.

In addition to login issues, virtual machine data security is another dimension that requires extra attention. It’s recommended to use a reliable virtual machine backup software to secure the data within the VMs.

Delia · Editor
Delia owns extensive experience in writing technology-related blog posts, and has been a part of AOMEI since 2020 to provide expertise in data security and disaster recovery. She works with Windows operating systems, SQL databases, and virtualization platforms such as VMware and Hyper-V, specializing in troubleshooting and advising on data protection and migration.