Question regarding use of nano in Terminal ^

If you just want to check a value, you don’t have to edit a file. Just run the following command:

sysctl net.inet.ip.forwarding

It should return:

net.inet.ip.forwarding: 0

Which is the default value. Why do you want to change it?

nano isn't mouse enabled. you move around nano by pressing the cursor key.

Skip the stuff on installation. It's already installed on macOS.

https://www.hostinger.com/tutorials/how-to-install-and-use-nano-text-editor

R

If you are just checking on values within a configuration file and you are not familiar or aware of the commands to check the specific values as @etresoft mentions, then using the "less" command is safer than using "nano" since you could accidentally edit the file you are viewing if you are not careful. With "less" you can use the arrow keys to scroll up & down within the file line by line or use the Page Up/Dn keys to scroll a page/window at a time, or the Home/End keys to scroll to the top or bottom of the file.

less  /etc/sysctl.conf

Starting with macOS Catalina many system files are stored on a read-only volume so you may not be able to edit them directly. If Apple expects certain system configuration files to be modified they will be located on a writeable volume, but I'm not sure how Catalina handles these situations when you want to manually edit a system configuration file. Instead it may be easier & safer to use the specific macOS system commands such as the one suggested by @etresoft.

If you modify a system configuration file, you should always back it up first just in case something goes wrong. It is so easy to make a mistake and sometimes the mistake can be so subtle that you will have a hard time even noticing the mistake. This is true no matter how experienced a person is with the command line.

This may not be a simple question, any familiarity with nano or less/more or other commands aside... What problem are you working toward solving with this current approach? Not how are you solving it with nano, but what is the more general issue or problem that you are seeking to address with the NAT forwarding settint?

macOS generally makes an expensive and problematic router, and NAT is whole buckets of fun, but that’s hopefully all fodder for another time and you can (hopefully) avoid using a Mac as a router...

Here? Use the sysctl command.

View:

sysctl net.inet.ip.forwarding

Change:

sysctl -w net.inet.ip.forwarding=1

I don’t, however, have a Catalina system handy to check.

etresoft wrote:

That file doesn’t normally exist at all.

Thanks, I'm not familiar with macOS system internals. I only used it as an example on how to use "less" since the OP provided the path to that file in an earlier post.

For future reference, ^ means hold the Control Key while typing the letter that follows the ^

^R means Control-R

^O means Control-O

^X means Control-X

etc...

That file doesn’t normally exist at all.

No big deal. I doubt that the OP is ever going to reveal the big mystery anyway.