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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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 ...
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 ...
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 ...
26
votes
2answers
14k views

Xcode.app gets scanned by socketfilterfw (OS X Firewall) at every launch

Situation: When I launch Xcode, socketfilterfw, OS X's application based firewall, starts using a lot of CPU. After some research I narrowed it down to this: socketfilterfw reads all the files in ...
22
votes
4answers
30k views

How can I get the exact URLs/requests that a program is trying to connect to?

I currently use Little Snitch to control network traffic on my Macbook Pro, and see what my apps are connecting to. Unfortunately, Little Snitch only shows you the hostname that an app is connecting ...
21
votes
4answers
13k views

Enable ssh-key-only login to my Mac for 1 user

I have a Macbook Air that I would like to allow remote SSH access to without a password. I have created a user called remotepair that I have logged into and verified I can used the Mac with. I have ...
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.
18
votes
2answers
15k views

Reasons to prefer Little Snitch over the built-in firewall

Every now and then I browse through software you must have on your mac type lists and more often than not somebody mentions Little Snitch as a must-have application. Now what I think that many people ...
18
votes
3answers
45k views

How can I open a port (not application) in the OS X 10.6 firewall?

Let me preface this by saying: I do not want to drop my firewall completely Yes, I really do need particular ports rather than an application. So I see that there is the option to allow particular ...
16
votes
4answers
28k views

What is the “akd” process, and do I need to allow it to connect to the internet?

I use Little Snitch as a Mac OS firewall. Usually, it's fairly clear to me what needs to connect to the internet and what doesn't. However, I can't figure out what akd is or does, and why it needs to ...
15
votes
4answers
53k views

How to open a specific port in Firewall OS X 10.9.4

How do I open a specific port in the firewall? I can not use the "allow connections from application" as I want to open the port for Jenkins, that is not on the list...
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. ...
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 ...
13
votes
2answers
5k views

Disable Little Snitch in guest account?

It's annoying as hell to let others use your computer on a guest account with Little Snitch installed, all the consecutive popups one after another...it's really ridiculous. Also in the event my ...
12
votes
4answers
16k views

Why does Microsoft Word need to allow incoming network connections?

When I turn on the Mac firewall I get prompted to allow the MS office apps (Word, Excel, Powerpoint) to accept incoming connections. Why is this, and is it safe to allow it ? I'm running Mac OS 10.7....
11
votes
1answer
29k views

Firewall for outgoing connections

Is there a firewall for OSX Lion, that allows controlling of outgoing connections? The built in firewall handles only incoming connections, apparently.
11
votes
1answer
27k views

MacOS X - iptables?

Where is iptables in MacOS X? I'm running Yosemite 10.10.5 (14F27) and it seems to be missing. If it's not actually native to OS X, what's the best way to install it for this operating system? If for ...
10
votes
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.
8
votes
3answers
6k views

Blocking incoming hostile traffic dynamically with PF and fail2ban on OS X

The bigger picture is that I am trying to dynamically block/unblock IPs using fail2ban 0.8.14. I have been following an old guide for OS 10.5 with doesn’t include PF. I think I’ve configured ...
8
votes
2answers
4k views

Can I block ports and network traffic when using Personal Hotspot?

I would like to block ports and network traffic when using my jailbroken iOS device as a Personal Hotspot. The reason is I don't want my backup program, computer updates, or any high bandwidth usage ...
7
votes
1answer
3k views

Dropbox109 process asking to access firewall on Yosemite

As the title says, I have a process called Dropbox109 asking to access the internet. I have denied it. I have Dropbox installed since Mavericks, and its been working fine (uploads/downloads/sync). ...
7
votes
1answer
547 views

Always Asked to Configure Firewall for iTunes

Whenever I open iTunes, I get the standard OS X dialog, Do you want the application "iTunes.app" to accept incoming network connections? Every time I click allow, but I am asked the same thing without ...
6
votes
2answers
7k views

How do I drop outgoing packets to specific host/port?

I want to test something locally. For that, I'd like to be able to drop outgoing packets sent to a specific host/port. I tried messing around with pf rules using Murus (the non-free version), but have ...
6
votes
4answers
1k views

Open ports. Safe?

My friend is currently running the default firewall with "Block all incoming connection" (except the basic ones like 80). I just scanned his mac for open ports and I found the following: Open TCP ...
6
votes
3answers
30k views

How can I setup my mac (OS X Yosemite) as an internet gateway

It should be possible, but I searched for a day and cannot get a decent HowTo. There seemed to be a Gateway Setup Assistant, but the Wikipedia link only goes to the server app now. Maybe it is easier ...
6
votes
3answers
912 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 ...
6
votes
3answers
14k views

Little Snitch reports outgoing connections for AirPlayXPCHelper for wrong subnets?

After upgrading to El Capitan, I've started noticing annoying connections from the AirPlayXPCHelper to 192.168.1.0/24 subnet (my home network isn't in 192.168.1.0/24 subnet, it's in 172.16.0.0/12 ...
6
votes
5answers
3k views

Is there a way to use different network connections for different apps

At work we have a firewall that prevents certain outbound connections. But I also have a Clear wireless personal hotspot. I would like to use the work connection for normal requests but for certain ...
6
votes
1answer
3k views

pfctl - howto add an anchor and make it active / load it

So i can add an anchor to the already enabled firewall by doing something like this: $ pfctl -a anchor_name -f /etc/anchor_rules.txt the file "anchor_rules.txt" might contain something like this: ...
6
votes
3answers
6k views

Questions about how Internet Sharing works

A simple checkbox and a menu allow you to share your internet connection (no matter which interface you get it on) with any other interface (theoretically). But, the guts of this is a little confusing....
6
votes
2answers
11k views

Migration Assistant fails on Ethernet Mavericks-to-Mavericks migration

I have the following setup and am attempting the use Migration Assistant over Ethernet: Source machine: Early 2009 24-inch iMac running OS X 10.9 Destination machine: Latest MacBook Pro Retina ...
6
votes
2answers
3k views

“Accept incoming network connections” issue

Due to some graphic and/or code based changes, within programs like Dropbox, iTunes, jDownloader etc. (but mostly Java-based applications), the built-in firewall keeps asking for verification. ...
5
votes
1answer
2k views

How to Use Terminal for “Little Snitch” Functionality without Little Snitch

I'm a Terminal newb, and trying to wrap my head around manual "Little Snitch" functionality without using Little Snitch. From the research I've been doing, I've landed on the fact that I need to ...
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 ...
5
votes
2answers
3k views

How does Application Level Firewall work?

I'm a bit confused about OS X Mountain Lion's Application Level Firewall. I have enabled ALF (Application Level Firewall) in Settings -> Secuity & Privacy -> Firewall and have some rules for some ...
5
votes
1answer
670 views

How to open port 9150 on a Mac so external devices can connect to it?

On Localhost I can access and connect to port 9150, but on another devices on the network it cannot see the port and cannot connect to it. I've checked and there is no firewall on the network ...
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 ...
5
votes
2answers
10k views

Mac OS X Server ignores remote HTTP connections, but accepts local ones

I cannot get Mac OS X Server's web server to accept connections from other machines on the same LAN. This is on OS X 10.8.2, running on a Mac mini which originally shipped with Lion Server. I can ...
5
votes
2answers
36k views

How to open a port in macOS Sierra 10.12.4

I'm running macOS Sierra 10.12.4 and am trying to open a port (12345). I can't use the GUI firewall tool as it's app specific, not port specific. I have tried the following this article, but it did ...
5
votes
1answer
846 views

Which built-in tools do Little Snitch-like applications rely on?

Little Snitch is a well-known piece of software that allows Mac users to block outgoing connexions from a specific app. Now, whenever I ask how to do the same with built-in OS X tools, I get an ...
5
votes
2answers
5k views

How can I tell Firewall to allow incoming connections for Python.app running Django

Each time I run my Django development server, I get a dialog to allow incoming connections. No matter what I do : Click Allow in the dialog box Add to the Firewall via the OS X GUI (both real and ...
5
votes
2answers
4k views

What are the numerous incoming connections I see on public wifi for?

In general I have incoming connections disabled by my security software (Little Snitch). But even when I do this, on public wifi, I see numerous incoming connections for netbios and mDNSResponder ...
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 ...
5
votes
1answer
383 views

Mountain Lion firewall is randomly delaying DNS requests

I recently experienced some delays during DNS host resolution on OS X 10.8. To test it I started a simple script which tries to repeatedly resolve the same hostname 20 times: #!/bin/sh for i in `seq ...
5
votes
2answers
6k views

Fixing “a sealed resource is missing or invalid” warning

I've changed the application icon of my Eclipse editor, and this causes a confirm dialog to pop up asking me if I allow the program to accept incoming network connections. I faced this before, but ...
4
votes
3answers
8k views

Is allowing port 80 on Little Snitch safe?

In Little Snitch, I allowed port 80 when a "google.com" popup appeared on my screen. I'm wondering if that was a good idea. If a hacker installed a program on my Mac, and that program sent ...
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 -> ...
4
votes
3answers
8k views

How does one lock down OS X Server using the PF firewall?

Assume I have ip blocks for China, Russia, North Korea etc. How would I configure pf to allow those IP addresses to only access ports 80 and 443, and be denied access to other ports? I have an ...
4
votes
1answer
6k views

Is ipfw available in Mountain Lion?

Is ipfw available in Mountain Lion? The reason for asking is that they introduced pf in Lion, but kept ipfw, however there is a chance that ipfw would eventually be removed. I found this: Can I use ...
4
votes
1answer
11k views

How to stop Windows firewall from blocking Bonjour hostname resolution

I have Bonjour installed on my Windows 7 PC, and the installer appears to have poked all the necessary holes in the Windows firewall. However, I can't ping windows-pc.local from my Mac. If I ...