Disable IPv4 on Red Hat 7.3

aidylewis · 07-13-2017, 08:44 AM

I am trying to disable IPv4 on Red Hat 7.3. I would have thought this would have been a kernel setting or an ip down on a network interface.

Many Thanks

Aidy

Rickkkk · 07-13-2017, 09:42 AM

Hello aidylewis,

A quick web search yielded this information. I suggest you give it a try.

Code:

Here's how to disable the protocol on a Red Hat-based system:
Open a terminal window.
Change to the root user.
Issue the command sysctl -w net.ipv4.conf.all.disable_ipv4=1.
Issue the command sysctl -w net.ipv4.conf.default.disable_ipv4=1.

Cheers :-)

aidylewis · 07-13-2017, 10:32 AM

Dear Rickkkk

Thanks for your reponse but I made a mistake and I am on Amazon Linux:

Code:

cat /etc/*release
NAME="Amazon Linux AMI"
VERSION="2017.03"
ID="amzn"
ID_LIKE="rhel fedora"
VERSION_ID="2017.03"
PRETTY_NAME="Amazon Linux AMI 2017.03"
ANSI_COLOR="0;33"
CPE_NAME="cpe:/o:amazon:linux:2017.03:ga"
HOME_URL="http://aws.amazon.com/amazon-linux-ami/"
Amazon Linux AMI release 2017.03

And I receive:

Code:

sudo sysctl -w net.ipv4.conf.all.disable_ipv4=1
error: "net.ipv4.conf.all.disable_ipv4" is an unknown key

Would the kernel be compiled that differently?

DavidMcCann · 07-13-2017, 10:39 AM

As you see, you were absolutely right to think this was a kernel setting: sysctl gives you considerable (and dangerous!) powers over the kernel.
http://access.redhat.com/documentati...c-dir-sys.html
See also the man pages for proc and sysctl.

Oops! Our posts have crossed! Amazon Linux in a cut-down version of Red Hat. This would work in CentOS, but evidently that bit was thought unnecessary by Amazon.

You could try adding
net.ipv4.conf.all.disable_ipv4=1
net.ipv4.conf.default.disable_ipv4=1
to the end of the file /etc/sysctl.conf and see if that works.

On reflection, I'm not sure that you can disable ipv4 and leave ipv6 in place: I think ipv6 may require some ipv4 code, but this is all a bit beyond me. Usually people want to know how to rempve ipv6. Perhaps you could tell us why you want to do this? There might be another solution to whatever your problem is.

Rickkkk · 07-13-2017, 10:50 AM

Quote:

Originally Posted by aidylewis

Dear Rickkkk

Thanks for your reponse but I made a mistake and I am on Amazon Linux:

And I receive:

Code:

sudo sysctl -w net.ipv4.conf.all.disable_ipv4=1
error: "net.ipv4.conf.all.disable_ipv4" is an unknown key

Would the kernel be compiled that differently?

Hi again aidylewis,

I believe your best course of action would be to follow DavidMcCann's suggestion to begin with, and read up on the applicable commands for your version of linux.

I am neither a generic RHEL nor Amazon Linux user, so it would be more prudent to wait for/seek advice from members more experienced in those distros. I wouldn't want to lead you astray ... :-)

Cheers.