Run MTR on MacOS without sudo

Coming from Linux/Windows it rather feel bothersome to run mtr with sudo each time if you want to quickly diagnosis a hostname/IP address.

Since, mtr require access to raw packets. MacOS permissions doesn't allow it to access those raw packets without sudo, fortunately we can fix that by setting ownership of executables to root and SUID by following steps -

Step 1: Find path of mtr executables

First we need to find the path of mtr-packet which is another program which handles the networking and does the actual tracing.

command -v mtr-packet
/opt/homebrew/sbin/mtr-packet

Here we can see, it's residing at /opt/homebrew/sbin directory, but that's not the true location of it, let's figure out why!

ls -lsh $(command -v mtr-packet)
0 lrwxr-xr-x 1 jugal admin 34 Aug 31 23:28 /opt/homebrew/sbin/mtr-packet -> ../Cellar/mtr/0.96/sbin/mtr-packet

Ah, we can see /opt/homebrew/sbin/mtr-packet is actually linked to /opt/homebrew/Cellar/mtr/0.96/sbin/mtr-packet, that's where we are going to apply the necessary permissions.

Step 2: Change ownership of executables to root

Change ownership of mtr-packet to root user by issuing following command -

sudo chown root /opt/homebrew/Cellar/mtr/0.96/sbin/mtr-packet

Step 3: Set SUID bit

We also need to set SUID (Set User ID) to 4755 -

sudo chmod 4755 /opt/homebrew/Cellar/mtr/0.96/sbin/mtr-packet

Run the mtr command again, and it should work without prompting you for sudo password.

Note: The paths given as example are taken from Homebrew on M4 cores, Mac Intel architecture's path may differ.

Reference(s):

• Dave's Network Blog

• Dzubayyan's Articles