CentOS - Jan 2008 - modprobe.conf and ipv6

Greetings,

Are these still valid modprobe.conf for centos 5 ?

alias net-pf-10 off
alias ipv6 off

Secondly, Are they still valid in centos 5 for the same reasons we put them
in the modprobe.conf for centos 4 ?

The centos wiki says yes.

It used to be a "speedup" issue in centos 4 among other things if I
recall
correctly.

What I don't understand is, if you turn off ipv6 on the NICs, why do we have
to do this in modprobe.conf?

Thank you in advance.

 - rh