Odd Permission from firewall regarding Adguard


New Member
Hi there,

First off, I must say that I love your product. I’m an undergrad university student and even with my constrained college budget, I recently bought a lifetime Adguard license for my Mac. I also purchased a license for the iOS Adguard as well.

I’m a security conscious user and like to maintain control on all of my devices. Therefore, when I switched over to macOS from Windows recently, I looked for a solid firewall product to monitor my outgoing connections. I bought the Little Snitch firewall app and it has been working splendidly.

Recently, however, Little Snitch threw an odd message regarding Adguard. The message stated that Adguard via adguard-tcpkill was attempting to access: /dev/bpf0 (Berkeley Packet Filter)

Here is a direct link to an image of the alert from my firewall:
I have also attached the image to this post.

What is this Berkeley Package Filter and should I allow Adguard access to it? Currently, my firewall (Little Snitch) is restricting Adguard’s access to it - whatever it is. Adguard seems to be working fine but my browser is acting very strangely.

I use Mozilla Firefox and every time I launch this browser, my entire OS freezes for 5-8 seconds after which the browser finally appears. Then, the browser freezes up for another 2-3 seconds. After that, everything goes back to normal. Is this odd behavior related to Little Snitch blocking adguard-tcpkill from /dev/bpf0 (Berkeley Packet Filter)?

Some information:
OS: macOS Mojave (v10.14.6)
App: Adguard for Mac (v2.1.2.595 release (CL-1.4.138)

Thank you and I look forward to hearing from you soon.