Questions tagged [firewall]

Typically software that runs to prevent network traffic from reaching a computer. Also a hardware device that works on a network level rather than running on a single computer.

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3
votes
2answers
141 views

Figuring out what is blocking HTTP request on macOS Mojave?

I have a simple http-server running with an index.html, which I'm trying to serve over to another device over LAN. I can access the website in the host computer using localhost and it is recorded as a ...
20
votes
3answers
66k views

How to restrict “Remote Login” (ssh) access to only certain IP ranges?

Can someone please tell me how to restrict SSH access only to certain IP ranges (e.g. local network) and not the whole Internet? I guess this has to be done via firewall.
3
votes
1answer
52 views

pf redirect rules don't work logging

TL;DR: On Mojave (haven't tested on others), when creating rdr rules in pf, the rules work for a while (with some issues accessing the target port directly), but after a while the rules stop working, ...
2
votes
0answers
674 views

How to configure MacOS firewall to block outgoing IP ranges?

Recently I was watching a Gizmodo journalist's videos about her experiment with blocking outgoing connections to Google, FB, Microsoft and Apple. I wonder if it is possible to modify MacOS's built in ...
98
votes
10answers
88k views

How to get rid of firewall “accept incoming connections” dialog?

I've accepted this so many times that firewall should already remember it. For example, I get it for Eclipse when starting my java programs in debugging mode ... sometimes this dialog is displayed ...
1
vote
1answer
35 views

Where can i find the source code for the pfctl utility?

I have looked here: https://github.com/apple/darwin-xnu But all i can find is the 'back end' for the pfctl tool, but i am interested in the command-line pfctl tool itself, the option parser and so on....
0
votes
1answer
46 views

How to route traffic out a non-standard interface using pfctl?

I have a VPN which has setup a default route, which is (of course) different to my gateway. All my traffic therefore gets routed through the tunnel. however i would like to exempt certain apps from ...
0
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0answers
16 views

Program mouse and keyboard movements to be run with input on Mac

This is a very specific question. I'm running a gaming server for my friends and I to play on (on my old iMac that I just use as an external monitor for my MacBook Pro now), and I have a firewall in ...
0
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0answers
53 views

Mac OS X firewall rules to block UDP connection to an external server

Can anybody help to recommand a firewall app for Mac OS X? I'm going to block UDP connection to an external server, and then I need to check whether it switch to TCP connection to the server ...
0
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2answers
102 views

PF Firewall : Every time I use `pfctl`, I get errors about ALTQ support

I have a slightly elaborate firewall setup where my server usually has between 400 and 800 ip addresses firewalled. It switches back and forth between two different pf tables. Every day it rebuilds ...
0
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0answers
17 views

Any way to block a specific HTTPS request from a specific application?

There's an app running on my mac (macOS 10.12.6) that occasionally makes an HTTPS request to a resource at a specific URL. I'd like to block this request, but allow all other requests from this ...
1
vote
1answer
200 views

Routing localhost traffic to external IP address

I have a host with Mac OS and another machine (192.168.100.50) in the same LAN. I would like to configure Mac OS in that way if I access localhost:443 it will redirect to 192.168.100.50:443. I'm able ...
2
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0answers
29 views

macOS: Restricted admin account

Is it possible to create an admin account which will allow you to install programs, but not to force install programs that are not verified? In other words, an account that can do anything accept ...
1
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0answers
28 views

Enable packet filter firewall (pfctl -Ef) temporarily stops all network connection

I've noticed that when re-setting my firewall with a new set of rules, all network communication completely stops for a short time, until it regains with the new set of rules. In fact, it also ...
0
votes
1answer
181 views

Can I Open Port 443 on my MacMini without using the Server App?

I'm using an AT&T router where I have port 443 open. I did a port scan and it does not show 443 open. I have the firewall open with all the default options listed that Allow incoming connections. ...
5
votes
3answers
7k views

Blocking internet access for a specific application on Mac OS X

How can I block internet access to a specific application in Mac OS X? I need this to be done from the command line and hopefully use the ipfw terminal command. Specifically I am looking to toggle ...
6
votes
3answers
911 views

How to launch pf at startup?

I am looking for a pretty elegant way to launch the pf - a.k.a. Packet Filtering - process at startup. Using the launchctl or the pfctl commands, root privileges are required and so it is useless to ...
2
votes
1answer
202 views

How to start pfctl at boot

Before El Capitan I used to enable pfctl at boot by adding -e to the start up parameters. In /System/Library/LaunchDaemons/com.apple.pfctl.plist <string>/sbin/pfctl</string> <key>...
1
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0answers
106 views

How to block TCP connections from unidentified IP addresses mac

I started up a private minecraft server for my friend and I, and that required me to use generic TCP forwarding in order to open it up to accept his IP address. I used this program called serveo.io ...
4
votes
5answers
1k views

I'm trying to block game “X” from accessing the internet including updating

I'm using OS X El Capitan and I'm trying to prevent a game from accessing the internet including blocking it from checking for updates for the launcher or the game itself. I've gone into Security -> ...
0
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0answers
15 views

Firewall off by default, and when I turn it on it doesn't block connections

Yesterday, I had to get a PHP app running locally on my brand new, plain-vanilla Mac Mini. I was disturbed (to put it mildly) to discover that Apache was already installed, and running, and serving ...
3
votes
3answers
2k views

How to limit the bandwidth on a per-application (or per-process) basis in OS X Yosemite?

Whenever I use Homebrew or Apple Store to download a large application, it sucks all my available bandwidth and I am then unable to browse the web. How can limit the bandwidth per-application or per-...
1
vote
1answer
30 views

Blocked websites on macOS host but not on Win7 virtual machine

In China there in the Great Firewall which blocks i.e. youtube. Fortunately in my university in China someway they provide access to youtube, so students can use youtube by means of campus wifi. I ...
14
votes
1answer
11k views

How stealthy is the stealth mode of the firewall? Does it increase security?

In the System Preferences there is the option: `Security & Privacy -> Firewall -> Advanced... -> Enable Stealth Mode Does this options significantly increase the security when ...
10
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2answers
25k views

Does iOS have a firewall?

Does iOS support a built-in firewall like macOS does? I don't see anything about it in Settings.
0
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0answers
181 views

`pf` - No ALTQ support in kernel - ALTQ related functions disabled

I'm using pf on my server, and it's working great. So much easier to use than ipfw (after some initial config confusion). But there is one thing that is driving me nuts.... I'm sure you probably ...
1
vote
1answer
225 views

How to unblock an application with socketfilterfw?

I am compiling a software from scratch and running its tests. I do this often. The tests open ports and expect connections. Whenever I run the tests, I get the Do you want the application “run-...
1
vote
2answers
373 views

How to block everything except my connection to the VPN?

I'm trying to make Murus block everything, except my connection to the VPN server. I don't want my Mac to make any outbound calls to any ports unless via the VPN connection. I'm trying to add a rule ...
0
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0answers
782 views

PF Firewall on macOS Mojave - Block outbound rule not working (blocking Plex SSDP/UDP broadcast)

All, I'm new to pf please forgive my ignorance in advance. I'm attempting to block an SSDP/UDP Broadcast from my Plex Server on a Mac Mini to the LAN. The Mac Mini is on internal IP address 192.168.2....
2
votes
1answer
12k views

Apple USB Ethernet Adapter has a self-assigned IP address and will not be able to connect to the Internet

Cannot connect MacBook Pro (Retina, 15-inch, Mid 2015) (10.13.3) to the internet through my Apple USB Ethernet Adapter. I am receiving this error under System Preferences/Network: "Apple USB Ethernet ...
1
vote
1answer
76 views

Several applications trying to connect to IP

I have several applications on my computer which are attempting to connect to a small hand-full of IPs over port 80(http). This seems suspect to me and I'm not sure how to proceed. Currently I am ...
0
votes
2answers
1k views

Which incoming ports do you need to open in osx firewall?

I use pf (BSD packet filter via Terminal). The recommended use of pf is to block all incoming ports and then open those you need. I want my system to work properly and don't miss things like ...
15
votes
2answers
2k views

Do pre-built Little Snitch configurations exist and are they shared?

Is it possible to import configurations that have been created elsewhere into Little Snitch? For example, a ready to go basic ruleset for someone who wants to block iCloud's more intrusive features. ...
1
vote
1answer
434 views

How do I open a filtered port in pf?

I have opened a number of ports, and am familiar enough with pfctl, but even though I have opened various ports, then show up as "filtered" - which means of course that they are not open. How can I ...
5
votes
4answers
23k views

Firewall settings with “imagent”

Among others that I recognize, I have the "imagent" been allowed to pass true my firewall (allow incoming connection). What/who is it, and do I must have it or can I just block it. I do not ...
2
votes
0answers
173 views

How to prevent “Do you want the application foo to block incoming connections?” popup from command line

As a developer, I run a testsuite of some self-compiled binaries which try to listen on some ports on startup. This causes a barrage of popups "Do you want the application foo to block incoming ...
5
votes
1answer
609 views

socketfilterfw and repeating error messages

Every two seconds I get the following messages via Console: Standard 13:47:41.404793 +0100 socketfilterfw MacOS error: -67065 Standard 13:47:41.405321 +0100 socketfilterfw UNIX error ...
1
vote
0answers
202 views

use `pf` to allow TCP traffic on specific port (from specific subnet)

So, I've read various posts about how to use both the Application Firewall (apf or socketfilterfw) and the Packet Filter (pf) at the same time. I thought this would be straightfoward since I'm not a ...
1
vote
1answer
701 views

How to open two ports (both TCP / UDP) using pf

I own a MacBook pro (Retina, 15-inch, Early 2013), running macOS Sierra 10.12.2 as host computer and VMware Fusion Pro Version 8.5.3 with Windows 10 and Linux as guests OS's. So my question is how do ...
-3
votes
1answer
241 views

Who is trying to use the Stealth Mode as reported in Console

I found following in my Console on MBA 10.13 Stealth Mode connection attempt to UDP 192.168.0.12:52734 from 8.8.8.8:53 Stealth Mode connection attempt to UDP 192.168.0.12:57880 from 8.8.8.8:53 ...
2
votes
0answers
18 views

Getting notification when firewall settings have changed

I'm using packet filter engine to setup my Firewall connection. However, there might be other entities that may override my firewall settings on the same way (processes running with 'root' privileges ...
0
votes
1answer
3k views

Any tips for blocking an address range for outgoing packets?

Anyone used ipfw or pfctl to block an IP address range for outgoing packets? I would like to temporarily block Apple's IP address range 17.*.*.* to find everything that's phoning home phoning home. ...
27
votes
1answer
125k views

Should I block incoming connections from “netbiosd”?

My (application) firewall settings are configured to block incoming connections from netbiosd. I don't recall setting this myself, and wonder what the consequences are. What are the consequences of ...
2
votes
1answer
506 views

pfctl to add rules at runtime WITHOUT editing /etc/pf.conf?

I have an app that (while it is running and only while it is running) needs to make changes to the packet filter (pf) so that it blocks or allows certain traffic. These rules should be in addition to ...
2
votes
1answer
5k views

How do I use pf/IceFloor to block an outgoing connection to an IP address?

I am running an application that regularly phones home and reports a little more information than I'm comfortable with. I would normally add the reporting server's hostname to /etc/hosts, but the app ...
3
votes
2answers
2k views

Mojave install crashes after power on login

I have a mid 2012 MBA (4GB ram, 128GB SSD) that I have upgraded from High Sierra to Mojave 10.14. the upgrade finished successfully. When I power on I am presented with the initial logon screen, and ...
0
votes
0answers
86 views

Passing L2TP over IPSec VPN through a `pf` Firewall

I am trying to set up some custom firewall rules in the pf firewall in macOS (10.11 in this case). These are traditional network-based rules, not application-specific rules. I'm having some issues: ...
53
votes
3answers
62k views

What is the modern way to do port-forwarding on El Capitan? (forward port 80 to 8080)

The old utility ipfw was discouraged in recent versions of Mac OS X and is now gone from El Capitan. What is the modern way to do port forwarding in El Capitan? I simply want port 80 to forward to ...
1
vote
1answer
73 views

How can I reconfigure my PF.conf to be more secure

I want to make my computer more secure and a part of it I want to do with reconfiguring my PF firewall. How can I reconfigure my PF.conf to be more secure? I made a github repo where I posted my ...
4
votes
2answers
2k views

Little snitch and different network profiles

Is there any way to have different "little snitch" rules set for different networking profiles ? like for HOME one rule list for WORK another etc ...