I know by default IPv6 is enabled on the hypervisor, and we have been running like this for years, but we do not use IPv6 at our company. Is there really any pressing need to disable it?
There are no issues -
https://communities.vmware.com/message/1894943#1894943
Might be an issue, have seen that happening.
you have seen that eveusing the host just has that icmp generated ipv6?
If you are not using IPv6.0 disable it, if you enable IPv6.0 issues might come for DNS resolution, we had issue with Windows server domain login "Unable to establish trust relationship" error, resolved this issue with disabling IPv6.0 in registry and applying MS patch, might be ESX/ESXi also have issues if enable IPv6.0, best practice is to disable IPv6.0 and hardening ESX hosts.
I agree with what the others have said. If you're still completely oblivious to IPv6 on your networks and have no intention to manage or intentionally use it whatsoever, disable it if you can. Everywhere. Whether it's the hypervisors, VMs, physical servers, appliances, switches/routers or an IPv6-ready espresso machine.
Having said that said, the future is now (it's actually been sitting here since 15 years already), so get started on your IPv6 projects already.
Just remember that disabling IPV6 requires a reboot. If you defer the reboot, the next time you restart the mgmt agents all your VMs will be powered down hard.
Yea I am aware of that "feature"