Comment 2 for bug 1361542

Just wanted to add a comment since the practice of blacklisting the IPv6 module should have been deprecated by now in favor of using the "disable" module parameter. For example, this in an /etc/mod* file:

options ipv6 disable=1

That will load load the IPv6 module, but disable all its functionality, and has been in the Linux kernel ~5 years.

The disable_ipv6 setting can actually be switched on and off at will using sysctl, and is only saying the default action is to not enable IPv6 on interfaces, but the module is completely there and loaded. I think the check in the patch is OK, but there is the case where you could have default.disable_ipv6=1, but eth0.disable_ipv6=0.