vCenter 6.5 and DNS troubleshooting

[Syed Fawaz]

Hello Everyone,

We are running a virtualized vSphere 6.5 environment. We have vCenter server running on Windows server 2016.
Recently we faced issues in our vcenter. All our ESXI hosts went to a 'not responding' state. But we were able to access ESXi hosts
individually. But some of the servers had connectivity issues that impacted our infrastructure. We diagnosed the issue and found that it was actually related to the DNS. We are using infoblox device as our DNS/DHCP server. And just to let you know we have many hosts running on vCenter.

We were unable to ping to any of the esxi hosts from vcenter and it showed General failure upon pinging. We had another physicals server that helped us confirm that the issue was from DNS as it was giving direct error related to dns. We resolved this issue.

Now, my question is how can I solve this issue if this problem occurs another time? I want to make sure that we do not face any such issue again in the future. I am suspecting that the infoblox device malfunctioned as the vCenter was not able to resolve DNS entries. Since it was related to DNS, is it feasible or appropriate to have a separate DNS server just for our vCenter virtualized environment? Is this good for a production environment? What about using entries in hosts file in Windows vCenter server? But since we are a large environment, would it be good to do that???

Also let me know if there are any other possible solutions for this.



Please advice.

 

[gbaughma]

You should, at a minimum, have two DNS hosts. Usually the first one is your domain controller (if you're using a domain controller).

Here, we have one physical box as our PDC (Primary domain controller) and our backup domain controller runs on a VM.

Virtualization is great, as long as you're running vmotion so that if a host fails, your VMs get migrated to another host. You can set priority on HA in vcenter, so that if you have your DNS on a VM, you can migrate it first.

Hope this helps.


Just my $.02

"What the captain doesn't realize is that we've secretly replaced his Dilithium Crystals with new Folger's Crystals."

--Greg