On 08/29/2018 09:54 PM, Jamon Camisso via talk 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.
$ 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
That way tee is invoked with elevated privileges and writes its output to the file.
Or you can become root like on your Fedora system and use echo 1 >...
you could also do the following: sudo sysctl net.ipv4.icmp_echo_ignore_all=1 -- Alvin Starr || land: (905)513-7688 Netvel Inc. || Cell: (416)806-0133 alvin@netvel.net ||