4 Replies Latest reply on May 10, 2018 6:43 AM by BrianCunnie

    Is IPv6 broken in vSphere 6.5?

    7007VM7007 Enthusiast

      I upgraded my vCSA 6.0U2 to 6.5 and the upgrade went fine. I reassigned my IPv6 address to the appliance post upgrade but after rebooting it it loses the static IPv6 address.



      I then upgraded my first host from 6.0U2 to 6.5 and there were no errors during the upgrade and things seemed fine after the reboot but then the ESXi 6.5 host kept disconnecting from vCenter every minute or two. After much wasted time and troubleshooting I removed the IPv6 address from the host and ALL my disconnecting issues went away.



      So considering the above. is IPv6 broken/buggy in vSphere 6.5? I've been running a dual stack IPv4/IPv6 setup for ages with vSphere 6.0 and have never had a single issue with it so why does vCenter/ESXi 6.5 not work with a statically assigned IPv6 address? Is this a bug or known issue?

        • 1. Re: Is IPv6 broken in vSphere 6.5?
          internaut Lurker

          Same issue here.

          With Dual Stack running it's annoying with random 1sec disconnects.

          • 2. Re: Is IPv6 broken in vSphere 6.5?
            coza Novice

            I had the same issue.   I logged a call with VMware and it seems currently there is a mis-configuration of the sysctl.conf file that disables ipv6 on boot.


            Here is the orig /etc/sysctl.conf file (note the nice spelling mistake).  The second line is where it disables ipv6 on boot.   You just need to remove that line and it is all sorted.  

            #Disbaling SLAAC/Link Local addresses
            kernel.core_uses_pid = 0
            kernel.core_pattern = /var/core/core.%e.%p


            Apparently a fix is on its way but it is definitely in builds up to Build Number 5178943

            1 person found this helpful
            • 3. Re: Is IPv6 broken in vSphere 6.5?
              coza Novice

              I have just installed the current latest version 6.5.0-8024368 and it still looses ipv6 settings on reboot.     That line "net.ipv6.conf.eth0.disable_ipv6=1" no longer exists in the /etc/sysctl.conf file.

              • 4. Re: Is IPv6 broken in vSphere 6.5?
                BrianCunnie Novice

                On VCSA 6.7, ssh into your VCSA and run the following commands after you've configured both the IPv4 and IPv6 addresses; after the VCSA reboots both interfaces should be working properly:


                cp /etc/sysctl.d/99-sysctl.conf{,-orig} # backup file just in case
                sed -i s/disable_ipv6=1/disable_ipv6=0/ /etc/sysctl.d/99-sysctl.conf
                shutdown -r now

                1 person found this helpful