Permanent Use of IPv4

["Stephen P. Molnar" <s.molnar@sbcglobal.net>]

Thanks for help from this gropup I can force the use of IPv4 by 
running:  sysctl -w net.ipv6.conf.all.disable_ipv6=1.

For a number of reasons I have just done a fresh install of Stretch, 
hoping that the installer woould allow me to select IPv4, which, of 
course it didn't.

Although I have been using Linux since the early days of Slackware, I am 
not a hardware or OS person.

My question is how can I implement the sysctl statement on boot?

Thanks in advance.

--
Stephen P. Molnar, Ph.D.
Consultant
www.molecular-modeling.net
(614)312-7528 (c)
Skype: smolnar1