When deploying Prism Central on my Nutanix CE 2.1 cluster, I was faced with an error message that prevented registering my cluster on Prism Central…

Indeed, once all the parameters are filled in during validation, I get the error message “Cluster has dual stack enabled. Cannot register to a PC.” :

This error message is related to the presence of IPv6 in parallel with IPv4 on the cluster, but a solution exists and it resides in the following command:

manage_ipv6 unconfigure; manage_ipv6 disable

You must answer “Y” to the question “Proceed to remove above IPv6 configuration?” in order to validate the process:

nutanix@NTNX-436d2f97-A-CVM:192.168.84.200:~$ manage_ipv6 unconfigure; manage_ipv6 disable
[INFO] Initializing script… done
[INFO] Current IPv6 configuration on cluster: {
"svmips": {
"192.168.84.200": null
},
"hostips": {
"192.168.84.199": null
},
"prefixlen": null,
"gateway": null
}
[INFO] Note: This operation will restart the following services: ['CerebroService', 'StargateService']
Proceed to remove above IPv6 configuration? [Y/N]: Y
[+] CVM and Hypervisor IPv6 addresses unconfigured
[+] Cleared IPv6 configuration from Zeus
[+] CVM and hypervisor firewall rules updated
[+] Necessary services have been restarted
[INFO] Marked Ergon task 4673fda3-92da-4efe-59f5-1dd3fc51a6cd as kSucceeded
[INFO] Action unconfigure completed successfully
Script output logged to /home/nutanix/data/logs/manage_ipv6.out
[INFO] Initializing script… done
[+] IPv6 disabled on CVMs and Hypervisors
[INFO] Marked Ergon task 9cdfcb37-436a-479f-4d7a-08ef69e266b0 as kSucceeded
[INFO] Action disable completed successfully
Script output logged to /home/nutanix/data/logs/manage_ipv6.out
nutanix@NTNX-436d2f97-A-CVM:192.168.84.200:~$

Once the procedure is completed, the Prism Central registration goes smoothly:

If you still have issue, Goerge bring us another way to disable dual stack :

Add all these lines in /etc/sysctl.conf:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.all.disable_policy = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.default.disable_policy = 1
net.ipv6.conf.eth0.disable_ipv6 = 1
net.ipv6.conf.eth0.disable_policy = 1
net.ipv6.conf.eth1.disable_ipv6 = 1
net.ipv6.conf.eth1.disable_policy = 1
net.ipv6.conf.eth2.disable_ipv6 = 1
net.ipv6.conf.eth2.disable_policy = 1
net.ipv6.conf.lo.disable_ipv6 = 1
net.ipv6.conf.lo.disable_policy = 1

Run :

sudo sysctl -p 

And rolling reboot of all the CVMs.

Then run manage_ipv6 unconfigure :

manage_ipv6 unconfigure; manage_ipv6 disable