Re: Proposal to apply mask to IP address set on rule

Andy Ruhl <[email protected]> Fri, 23 May 2025 16:18:05 -0700

Newsgroups	gmane.os.netbsd.devel.network
Message-ID	<CAJcb3foAE7o3ct_rTX+K86KA_-MoFrZHUxVWtZcCzcwmCp5KzA@mail.gmail.com>

On Wed, May 21, 2025 at 9:16 AM Emmanuel Nyarko <[email protected]> wrote:
>
> Supposed we want to block or pass packets from a subnet
>
> Say 192.168.64 subnet.(24 bits masking)
>
> So if We
> "pass from 192.168.64.7/24" on a rule.
>
> Is it ideal to also match all packets from 192.168.64 subnet ? As it would if we passed as
> 192.168.64.0/24 on rule.

Allegedly I'm a network guy.

When you add the subnet mask to a rule, to me that means "use the
subnet that the address resides in".

For example

nmap -sn -n 192.168.64.57/24

means "scan 192.168.64.0/24"

If you're applying an IP to an interface with the mask, it's just
indicating the mask for the IP.

Andy