[GTALUG] Ubuntu -- Disabling Ping

Howard Gibson hgibson at eol.ca
Wed Aug 29 23:23:08 EDT 2018


On Wed, 29 Aug 2018 21:54:15 -0400
Jamon Camisso via talk <talk at gtalug.org> wrote:

> On 29/08/18 21:44, Howard Gibson via talk wrote:
> >    I am playing with my hack Ubuntu machine, and I am sorting out
> > security. I want to disable ping.  This is a laptop, and I want to
> > document the application of aluminium foil.
> > 
> >    The standard ping disabler is the following line...
> > 
> > # echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all
> > 
> >    This works fine on my Fedora laptop.  On Ubuntu, I get...
> 
> The # makes me think you are root on the Fedora laptop.

   Yes, I have a Fedora laptop, and that is how I disable ping.

> > $ sudo echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all
> > -bash: /proc/sys/net/ipv4/icmp_echo_ignore_all: Permission denied
> 
> That's expected with a sudo echo > redirect invocation. The shell is
> doing redirection. sudo is invoking echo, the output of which is being
> redirected in your normal user's shell to a file that you do not have
> permission to write to.
> 
> Try this if you want to go the sudo route:
> 
> echo 1 |sudo tee /proc/sys/net/ipv4/icmp_echo_ignore_all

   It works!

   Thank you.  

   Now all I have to do is stick it in a boot script.

-- 
Howard Gibson 
hgibson at eol.ca
jhowardgibson at gmail.com
http://home.eol.ca/~hgibson


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