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Seems that there are still some issues with vSphere 6.5, with a possible PSOD (Purple Screen Of the Death) after upgrade to 6.5U1 on ESXi hosts using 10 Gbps NICs. The VMware KB 2151749 describe this issue and explains that this occurs because Netqueue commit phase abruptly stop due to the failure of hardware activation of a Rx queue. As a result, Internal data-structure of the Netqueue layer’s could go out of sync with the device and cause PSOD.

One of the big advantages of the virtual appliance version of VMware vCenter (vCSA) is the ability to update both the OS components and the VMware parts with a simple menu. Just use the administrative UI available at https://vCSA_IP:5480 and login with user root and the password that you have choose during the deployment.

The Link Layer Discovery Protocol (LLDP) is a vendor-neutral link layer protocol used by network devices for advertising their identity, capabilities, and neighbors on an IEEE 802 local area network, usually with Ethernet standard. Compared to Cisco Discovery Protocol (CDP) it’s not proprietary and can be used from different vendors. VMware vSphere adds LLDP capability in the Distribuited Virtual Switches (DVS). CDP it’s also available both in DVS, but also in standard virtual switches (by default it’s enabled in listen mode).

If you choose to install the vCSA 6.5 in two different components, you may have an error during the PSC custominization (happens also on latest 6.5U1): An error occurred while starting service ‘pschealth’ This it’s related to a failure of identity management service error on first boot, so during the phase 2 of the deployment where the appliance has already been upload, but still must be configured.

In a VMware infrastructure, when you build a new VM, the default compatibility level could depend on your vSphere version, from which client you are using (the legacy vSphere Client does not ask for VM virtual hardware version in the default wizard), but also from your cluster settings. VM virtual hardware version defines exactly the compatibility level, but you can define the default level using the vSphere Web Client or the new HTML5 Client.

Using the legacy vSphere Client is no more possible in vSphere 6.5, but with the previous version is still an option. Unfortunately, it lacks not only in all the new features but also in consistency and error reporting. A curios issue was with a vSphere 6.0 environment where a generic warning message appears on the Summary tab of the ESXi hosts. The error was a generic “Consiguration Issues” message.

Starting with vSphere 6.0, the new PSC component include not only the SSO part, but also a certification authority for certification management of all vSphere infrastructure elements (unfortunately is not been used yet by all the other VMware’s products). This simplified not only the certifications management (with auto-enrollment for expired certificates), but also the trust between the different connections.

Actually there are two different platform where you can run the vCenter Server components (including the PSC): Windows (both physical or virtual) or Linux (only with the vCSA, based on PhotonOS). Initially there was only a Windows version, then the vCenter Server Appliance (vCSA) was first introduced with the release of vSphere 5.0 and has since evolved to become the definitive deployment model for vCenter Server. Starting with vSphere 6.5 the vCSA has become the first choice and has raised the level of vCenter with new functionalities (not available on the Windows version).

Finally has been announced (or better, confirmed) that VMware plans to deprecate the Flash-based vSphere Web Client with the next numbered release (not update release) of VMware vSphere. What does it mean, that the HTML5-based vSphere Client will become the only GUI client… finally! After the death of the vSphere Client for Windows, written with C# and with several issues, like the console issues with Windows 10, but also with several inconsistency with the others clients, now it’s the turn of the Flash based client.

One propertiers of VMware (standard) virtual switches was the number of ports per switch. A parameter (120 was the default in ESXi 5.x) that define how many virtual NIC and/or vmkernel interfaces you can connect to the virtual switch portgroups. This parameter was static and any changes require a host reboot. But starting with vSphere 5.5 (see KB 2064511) this parameter has become “elastic”.

Several people are disabling IPv6 support in ESXi for different reasons: because of the minimum privilege principle (if you are not using a service, why you have to keep it enabled?) or simple because they don’t want any IPv6 address in the network. On Linux and Windows systems is become very difficult disable it and Microsoft itself does not recommend disabling IPV6: ” We do not recommend that you disable IPv6 or its components, or some Windows components may not function.” (

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