topic Re: Do vCenter require DNS or internet connection. in VMware vCenter™ Discussions

Do vCenter require DNS or internet connection.

IvarHome — Thu, 07 Feb 2019 22:14:41 GMT

Hi,

I recently noted strange behaviour. My vCenter work perfectly but something strange happens when connection to internet and DNS server losts. I just shut them down temporarily. vCenter processes/services stopped (I have 6.7 appliance and seen that from vCenter management web, in 5480 port) and web client wasnt accessible. After I restored DNS server and internet, vCenter after boot works again normally. I dont use names, all ESXi-s and vCenter by IP-s only.

Re: Do vCenter require DNS or internet connection.

GayathriS — Fri, 08 Feb 2019 06:26:23 GMT

This is very basic for anyone to have a rresolvable name and IP before we install or upgrade vcenter

DNS Requirements for the vCenter Server Appliance and Platform Services Controller Appliance

When you deploy the vCenter Server Appliance or Platform Services Controller appliance, similar to any network server, you can assign a fixed IP address and an FQDN that is resolvable by a DNS server so that clients can reliably access the service.

When you deploy the vCenter Server Appliance or Platform Services Controller appliance with a static IP address, you ensure that in case of system restart, the IP address of the appliance remains the same.

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

When you deploy the vCenter Server Appliance, the installation of the Web server component that supports the vSphere Web Client fails if the installer cannot look up the fully qualified domain name (FQDN) for the appliance from its IP address. Reverse lookup is implemented using PTR records.

If you plan to use an FQDN for the appliance system name, you must verify that the FQDN is resolvable by a DNS server.

Please mark this as "correct" or " Helpfull" if this answers your query.

regards

Gayathri

Re: Do vCenter require DNS or internet connection.

IvarHome — Fri, 08 Feb 2019 09:44:41 GMT

No, I dont have any FQDN set up. I always connect by IP and always connect only from the same local subnet. And when you set FQDN for some server and DNS server goes down, then usually no any server starts shutting down its services. And why the IP address must change after restart? I dont have any local FQDN registered in my DNS server for vmware products. Never was, altough I used vCenter about 10y now, beginning from version 4. But now was the first time I see it shuts down its own services. It was never doed this before. I have he newest 6.7 vCenter, with all updates. No, vCenter had not such requirements. The only software, I remember, that wanted also reverse PTR was vSphere Data Protection. This is fact - 1) I dont have FQDN set in DNS 2) I still use vCenter successfully. So, how I can use it then when exist such requirements?.

Re: Do vCenter require DNS or internet connection.

sk84 — Fri, 08 Feb 2019 11:30:09 GMT

If it works without DNS since version 4.1 as you say, then why this post? I don't understand you...

You shut down the DNS server and vCenter didn't work anymore. DNS is a prerequisite for deployment and installation. This is clearly stated in the documentation. So why should it be different later in operation? The fact that you have only configured your environment with IP addresses is another matter. This is possible and supported.

Basically it is quite simple:

Does everything work without DNS if you only have IP addresses configured and no FQDNs? If so, then vCenter does not need DNS.

However, if you have "strange" behavior or errors without DNS, assume that vCenter still needs DNS for some reason. So simple.

An Internet connection is not needed, but then some features like the Online Health Checks and the Update Manager are limited.

Re: Do vCenter require DNS or internet connection.

IvarHome — Fri, 08 Feb 2019 11:45:27 GMT

I dont talk about installation. My question is very simple - Do vCenter server usually shuts down its services when DNS server goes down? Yes or Not?

Re: Do vCenter require DNS or internet connection.

Vijay2027 — Fri, 08 Feb 2019 13:56:49 GMT

It depends on how you configured your Identity source, NTP, how the hosts are connected to vc(via IP or FQDN)

Here is one example when primary DNS server is unreachable:

VMware Knowledge Base

Re: Do vCenter require DNS or internet connection.

IvarHome — Fri, 08 Feb 2019 14:00:38 GMT

I dont have AD.