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sgctoday at 3:11 AM3 repliesview on HN

I just tried littlesnitch and it did not resolve very many ips to domains, which is pretty basic. It also failed to identify most processes, and they were grouped under "Not Identified". It appears these are known limitations of the Linux version [1]. So for that alone I need to stick with opensnitch.

[1] "Little Snitch for Linux is built for privacy, not security, and that distinction matters. The macOS version can make stronger guarantees because it can have more complexity. On Linux, the foundation is eBPF, which is powerful but bounded: it has strict limits on storage size and program complexity. Under heavy traffic, cache tables can overflow, which makes it impossible to reliably tie every network packet to a process or a DNS name. And reconstructing which hostname was originally looked up for a given IP address requires heuristics rather than certainty. The macOS version uses deep packet inspection to do this more reliably. That's not an option here." -- from https://obdev.at/products/littlesnitch-linux/index.html


Replies

littlesnitchtoday at 9:59 AM

Regarding unidentified processes: Little Snitch daemon must have been running when the process started in order to identify it reliably. It's best to reboot after installation so that Little Snitch starts before everything else. I should probably note this somewhere.

And regarding failed reverse DNS names: Little Snitch is sniffing DNS lookups. If lookups are encrypted, there is little it can do. We usually recommend DNS encryption at the systemd layer, not at app layer. This way we can see lookups on 127.0.0.53 and the actual lookup sent out is still encrypted.

Also, it's currently only sniffing UDP lookups, not TCP. The eBPF part is already very close to the complexity limits (700k instructions of allowed 1M) and adding TCP parsing would exceed this limit. It should be possible to forbid TCP port 53 with a rule, though. Some complex DNS lookups will fail, but routine things should still work.

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a022311today at 11:01 AM

I guess that makes sense, since it's pretty new. OpenSnitch is great software in terms of functionality but I find the UI lacking. If LittleSnitch can keep the same functionality, while improving the UI, I'm switching. My other current concern here is that the LittleSnitch UI is just a Webview and I think it would be much better if there was a native option (ideally GTK-based for me, but Qt would also be acceptable). Webviews are slow and full of bloat.

toredashtoday at 5:34 AM

Is there any DNS based software to do block/allow? Kinda lika what's present in CiliumNetworkPolicies in Kubernetes networking?

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