Fixing Intermittent IPv6 Kickstart Issues

For a work project, it became necessary to kickstart CentOS installations using only IPv6. This is because the provisioning VLAN is separate from everything else, we needed to set static IPv4 addressing in the kickstart, and there’s (currently) no way to have “installer only” network settings in a kickstart configuration.

It’s simple enough, just create a local-only IPv6 network on the provisioning server, announce it with radvd (and DHCPv6, for good measure), and just use those addresses for Anaconda’s boot parameters and kickstart’s url line. However, in Anaconda’s haste to start the installation, a small bug came forth…

On a seemingly random basis, it would show a dialog box like the one above, saying it could not download the kickstart file. (Note: The same thing can also happen during download of install.img) The most peculiar thing about this problem is that hitting OK, even just a few seconds later, would almost always result in the installation being successfully kicked off. So what’s the problem? Continue reading