You can run below command to enable IPV6 on iDRAC. Can you share the iDRAC FW version you have on the server racadm set iDRAC.ipv6.Enable Enabled
I ran "racadm racresetcfg" on a Dell R730DX server and now I'm trying to make the iDRAC accessible over IPv6. I'm 100% remote with no remote hands to physically access the server for me. My access is limited to SSH'ing to the Linux Operating System running on the Dell server. The addresses show at the bottom of the getniccfg command, but in the upper ipv6 settings, it shows IPv6 disabled.       Ip addresses redacted to protect private information.   Is there a command to enable IPv6? I've been scouring the Web including racadm manuals and haven't found it.    Perhaps it isn't that I need an "enable" command but rather a setting is missing, which is prevented Ipv6 from being enabled?  
Enable Ipv6 from racadm command line ( addresses already set )