Each time you add an ESXi/ESX host to vCenter Server, the IP address of vCenter Server is recorded on the ESXi/ESX host. If the host is behind a NAT and the vCenter Server is on a different network (and thus the address is not accessible due to the NAT), the host disconnects from vCenter Server after about a minute.

For example, the vCenter Server system might be on the main network (10.10.10.0), and a few of the ESXi/ESX hosts might be behind a firewall in the 192.168.5.x network. The hosts cannot reach the main network and thus become disconnected from vCenter Server.

VMware vCenter Server 6.5.x
VMware vSphere ESXi 5.1
VMware vCenter Server 6.0.x
VMware vSphere ESXi 5.5
VMware vCenter Server 4.1.x
VMware vSphere ESXi 6.0

Using NAT between the vCenter Server system and ESXi/ESX hosts is an unsupported configuration and there is no workaround.

For more information on network requirements, see the Network Prerequisites section under the Prerequisites for Installing vCenter Single Sign-On, Inventory Service, and vCenter Server section in the vSphere Installation and Setup guide.

For translated versions of this article, see:

• 日本語: vCenter Server システムと ESXi/ESX ホスト間での NAT の使用 (2083643)
• 简体中文: 在 vCenter Server 系统和 ESXi/ESX 主机之间使用 NAT (2087917)