Upgrade vCenter Appliance from 5.5 to 6.5 and 6.7 without DNS Hostname Resolution

[ChasPro]

I have a small, three physical host installation of vCenter Appliance 5.5 with hosts at ESXi 5.5.  I want to upgrade through vCenter 6.5 to vCenter 6.7 (to get away from Adobe Flash EOL issues) while incrementally upgrading ESXi to 6.0 and then 6.5 but I think I need to stop there due to Dell server compatibility limits. 

My concern is that I am deployed in a test network environment that does not have a DNS that I can add host/IP entries.  I've always only used the fixed IP addresses to access our machines and VMs since it is a testbed system.  The upgrade manuals and several posts here seem to require that the current vCenter appliance (and maybe a temporary name/IP for the upgrade appliance?) be listed in an DNS, or the upgrade script will fail.

(1) Is it true that the ISO-based UI driven upgrade process requires the current vCenter to be DNS name resolvable?

(2) Does there need to be a DNS entry for the temporary vCenter upgrade appliance name?

(3) Do the ESXi hosts also need to be name resolvable for either the vCenter appliance upgrade or the ESXi CD-ROM Boot upgrade method?

Is there a work around to not require a DNS entry?  One post suggested for such a small installation, it may be easier to just install a new vCenter Appliance and add the ESXi hosts to that vCenter instead of using the migration/upgrade script approach.

Any help would be appreciated.

[Jimmy15]

No DNS server required...
provide any network reachable ip/gateway ip...it works

regards

[VMAKS]

@ChasPro

Thank you for your post on VMware Communities.

Please refer to the the below URL for DNS Requirements for the vCenter Server Appliance
https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vcenter.upgrade.doc/GUID-24D34C53-B00E-47B7...

Before you deploy the vCenter Server appliance with a static IP address, you must verify that this IP address has a valid internal domain name system (DNS) registration.

You can also refer to the below article which discusses, "Is a DNS server still required when using a Static IP for VCSA?"

https://www.virtuallyghetto.com/2018/12/is-a-dns-server-still-required-when-using-a-static-ip-for-vc...

Arun Kumar

Install Upgrade Specialist

"Did you find this helpful? Let us know by completing this survey (takes 1 minute!)"

[ChasPro]

@VMAKS  ... If I review both of the provided links, the implication is that I do not need a DNS if I fill in both static IP and hostname fields with the statically assigned IP address, and that the DNS Server entry points to a default gateway that responds with failure quickly.

Is that a correct interpretation / path forward?

Because, if so, your comment, "Before you deploy the vCenter Server appliance with a static IP address, you must verify that this IP address has a valid internal domain name system (DNS) registration."  is a little confusing. Is there a different requirement for addressing existing components (e.g. the ESXi and current vCenter) via their known Static IP and then also having a resolvable DNS entry for the "new vCenter" being upgraded to?  Please clarify?

Secondly, how does this paragraph relate to that understanding ...

"Ensure that the ESXi host management interface has a valid DNS resolution from the vCenter Server and all vSphere Client instances. Ensure that the vCenter Server has a valid DNS resolution from all ESXi hosts and vSphere Client."

Would it also be the case that if my 3 ESXi servers are configured likewise, with all host fields set to the static IP addresses, that any vCenter Appliance Upgrade scripting and ESXi Upgrades (via CD-ROM booth method) would also succeed w/o a DNS FQDN resolution required?

This is really going to help me ... as I can't seem to find a company resource that can add to our existing DNS listings ... thanks for your help.

[ChasPro]

@Jimmy15 you're probably saying the same thing as that article mentioned below ... but in very 'short-hand'.  I'm not a network engineer or a sys admin ... so things really need to be clearly spelled out for me. I write software ... and I use computers ... but I don't do a lot of "IT". Thanks for your input. It give me hope at least 😉

[Jimmy15]

I came across the same issue and invested good time...which accommodate in a line today 🙂 ..good luck..

Don't forget to give Kudos , if solution worth it.

regards