03-06-2017 12:29 PM
In a recent Predictive Cluster Validation Summary for one of my clusters, Cloudera Proactive Support states:
"The following hosts have IPv6 enabled, which is against our best practices, because it can cause connectivity problems. This is discussed in the CDH documentation. (http://www.cloudera.com/content/cloudera/en/documentation/core/latest/topics/cdh_ig_req_supported_ve..."
Yet that page simply says that "IPv6 is not supported and must be disabled."
If this is a hard requirement, then why is there no documentation on *how* to disable IPv6 for the various supported OSs? I understand that Cloudera may not want to get into the OS configuration business, but at least pointers to vender documentation should be provided.
01-19-2018 06:52 PM
01-22-2018 09:41 AM
I am curious as to what the Proactive Support tests look for when testing whether IPv6 is enabled. Is it the existence of IPv6 addresses on interfaces or the presence of the IPv6 kernel module?
Red Hat's solutions indicate that you can either disable the kernel module via kernel boot options (results in other things breaking) or disable IPv6 on network interfaces via sysctl. Debian appears to be similar.
01-22-2018 09:57 AM
Based on what I see in the script/code, it's the presence of inet6 in the ifconfig output, which is included in the diagnostic bundle. If inet6 is present and in use, I believe that's the basis for the alert that was issued.
01-24-2018 02:46 PM
And to fully answer myself, here are the links to vendor documentation: