VMware – Change vCenter VCSA Network Configuration

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IMPORTANT: in this article will be shown several possible methods to change the IP Addressing of a vCenter Appliance Server and will be also shown which errors could be raised by the Appliance during this attempts. Make sure you do a full backup of this VM before any change to its configuration, as the vCenter Appliance is a core component of a VMware vCenter infrastructure.

Prerequisites

To change the IP address of the appliance, verify that the system name of the appliance is an FQDN. If, during the deployment of the appliance, you set an IP address as a system name, you cannot change the IP address after the deployment. The system name is always used as a primary network identifier.

Verify that the user who logs in to the vCenter Server instance in the vCenter Server Appliance is a member of the SystemConfiguration.Administrators group in vCenter Single Sign-On.

Methods

Let’s say you need to change the internal IP addressing of your IT/ICT infrastructure, so also your virtualized environment will need an important update. You have recently switched your network configuration from 2 routed subnets:

192.168.0.0/24
192.168.5.0/24

To a single subnet:

192.168.0.0/21

Let’s say we have a mix of devices with both dynamic (DHCP) and static IP addresses. Those using DHCP didn’t cause much of an issues, but those configured using static addresses required the subnet mask and default gateway changing (again, fairly straight forward).

The real issue could come when it come to change vCenter Server Appliance (VCSA) network configuration. The obvious place to look pointed toward the configuration option inside the vSphere Web Client: System Configuration -> Nodes -> x ->Manage -> Settings -> Common -> Networking.

However you could find the change IPv4 option grayed out (unavailable):

VMware - Change vCenter VCSA Network Configuration

In this case the settings are grayed out with a message “IPv4 configuration for nic0 of this node cannot be edited post deployment”.

Using Configure Management Network (SSH)

If the web client method does not work you can try connecting with SSH, using root account, on the vCenter Appliance server and by going to Console -> Alt-F2 -> Configure Management Network -> IP Configuration.

VMware - Change vCenter VCSA Network Configuration

If even in this case you see the message “Configure Management Network; Management network configuration not allowed” you can’t change vCenter Appliance IP address using this approach.

Even using /opt/vmware/share/vami/vami_config_net utility, ever in an SSH environment, should give the same result, giving you several errors stating “ImportError: No module named libxml2mod” (due to an incorrect version of the libxml2mod installed by default by VMware on VMware Appliace Server).

VMware - Change vCenter VCSA Network Configuration

VAMI

Using VAMI (vCenter Server Appliance Management Interface), accessible by going the URL https://:5480, is used to perform basic administrative tasks to the appliance configuration. These tasks includes changing the host name, the network configuration, NTP configuration, and applying patches and updates.

VMware - Change vCenter VCSA Network Configuration

If the previous methods have failed there is an high chance that also with VAMI you will get a denied message, like the following:

VMware - Change vCenter VCSA Network Configuration

Modifying the Network Configuration file (Linux)

As a last resource we can start an SSH session and modify the /etc/sysconfig/network/routes (let’s say from default 192.168.0.1 to 192.168.5.1) and then network configuration file /etc/sysconfig/network/ifcfg-eth0 (in this example we will change only netmask from NETMASK=’255.255.255.0′ becomes NETMASK=’255.255.248.0′).

You can modify these files using the included standard Linux editor vi.

Just save your modifications using :wq!.

Just reboot after the modification and you should have finally your vCenter Appliance Server with the new IP addressing (IP address, Netmask and Default Gateway).

NOTE: this has changed in vCenter Appliance Server 6.7 the configuration file has changed from: /etc/sysconfig/network/ifcfg-eth0 to /etc/systemd/scripts/network/10-eth0.network.