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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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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 ...
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1answer
50 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. ...
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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 ...
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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 ...
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212 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 ...
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`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 ...
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344 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....
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2answers
231 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 ...
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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 ...
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1answer
70 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 ...
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1answer
136 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-...
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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 ...
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171 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 ...
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1answer
167 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 ...
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0answers
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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 ...
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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 ...
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68 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: ...
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1answer
61 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 ...
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206 views

How can I block all ports with PF except port 80 and 443?

How can I block/close (or drop all the packets coming from) all ports with PF except TCP port 80 and TCP 443? So I only want to make use of port 80 and 443 via TCP. I tried this, but I receive an ...
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2answers
276 views

Firewall on. I blocked IP 93.184.220.29 with PF but it still popsup in netstat -n

The firewall is on. I blocked IP 93.184.220.29 with PF but it still popsup in netstat -n. How is that possible? jen:~ jen$ sudo pfctl -t blockedips -T show Password: No ALTQ support in kernel ALTQ ...
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0answers
16 views

HTTP requests stuck on ERR_CONNECTION_REFUSED, solved but with username issue

This is related to the OSX/Pirrit thread from here. After two days of debugging and visiting Apple stores, I eventually erased all data on the disk and migrated my files later with Migration Assistant....
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42 views

How do I unblock vm from firewall?

How do I accept anything from my virtual machine (named vagrant). Tried to add this row in the /etc/pf.conf: pass in from 192.168.10.11 to 192.168.10.1 where .11 is the vm and the .1 is the host. ...
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1answer
188 views

Is the firewall really pfctl, or another instance of pfctl?

I was mucking around with pfctl a while back, didn't get very far and forgot about it. Yesterday, I couldn't ssh into a remote machine. I disabled the firewall in system preferences but still had the ...
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1answer
396 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 ...
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0answers
389 views

Blocking Incoming Connections to Open Port Daemons

OS: macOS 10.13.5 High Sierra; HW: Mid-2010 MacBookPro7,1 13” 2.66GHz Core 2 Duo I am interested in blocking incoming connections to Apple’s two persistent daemons with internet-facing open ports—...
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44 views

Opera browser behaving strangely

I occasionally use Opera Browser, but it recently started behaving strangely. When I opened it today, it asked me for my password for the first time in a long time, if ever: I didn't think twice ...
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1answer
53 views

FTP Issues on MacOS, can't write on the disk

I'm developing a website for a client, but some space of the server we will be used to transfer large files of softwares like Maya Autodesk (my client working with 3D modeling). I'm trying to ...
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1answer
138 views

How to allow the “Word of the Day” screen saver to fetch the words with LittleSnitch?

A friend of mine (not on StackEchange) has used LittleSnitch to explicitly disallow Internet access for every process/app that attempted to access the Internet except the ones he actually needs to do ...
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0answers
217 views

Adjust MTU on Airport Extreme

I have a Mac Mini sharing internet via pf (Murus static NAT) to an airport extreme. If I set the MTU on its client (Macbook Pro, via the Wifi Preference Pane) to 1372, I get flawless internet. I'd ...
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0answers
55 views

How do I prevent Apple Remote Desktop broadcasting over a specific network interface?

I have two active network interfaces on my machine connected to two different subnets. I run Apple Remote Desktop Admin to administer hosts on only one of the two subnets. How do I restrict Apple ...
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1answer
315 views

pf.conf to block *only* a specific IP address when VPN is not connected

I'm trying to configure a packet filter firewall to block access to a small range of IP addresses when a VPN is not connected. My rules should allow https/http traffic apart from this small, specific ...
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1answer
7k 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 ...
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0answers
652 views

Captive portal on MacOS

I want to implement a basic captive portal. For the test setup, I have a mac mini connect to wifi (192.168.1.1) and ubuntu laptop connected to it via lan. What I am trying to achieve is for the the ...
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1answer
700 views

OS X Firewall blocking external connections to NGinx Docker container

I have an Docker container running NGinx on a macOS High Sierra machine behind a corporate firewall that cannot be disabled. The container is unable to be accessed externally from other machines on ...
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1answer
547 views

Redirect Local Port through bridge to Internet Shared static IP

I have my cable modem (10.0.0.1) to my iMac (10.0.0.36), and my iMac (10.0.0.36) with a (bridge100 192.168.2.1) Internet Shared IP to my debian machine (192.168.2.34), and all of that is working ...
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1answer
2k 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: ...
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73 views

Block internet/network access to a specific application, or just to launch an application?

We have a legacy application which tries to force login at startup - but the server is not accessible. If there is no internet it just skips login (talk about security). I have ethernet so I'm after ...
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0answers
47 views

PHP mail not sending (possible macOS Server or Firewall issue?)

This is a relatively complex problem and LONG description, so bear with me. Please ask questions in the comments if you think I can clarify something. I am hosting multiple websites on a single ...
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1answer
318 views

Murus internet sharing not working

I have Murus 1.4.12 and am following the directions to share my internet connection from en0 (static IP connected to Comcast modem/router) through en3. Both the client and server are macOS High ...
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1answer
41 views

Hardware Router For macOS [closed]

I "think" I understand that all firewalls are software. However, I am splitting the monthly internet bill with a roommate who has the ISP modem/router in his room. I would like add (if possible) more ...
3
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1answer
2k views

macOS packet filter (port forwarding)

I am trying to redirect the outbound traffic to destination port 80 to the local proxy port 127.0.0.1:8080 without success /etc/pf.anchors/com.forwarding rdr pass inet proto tcp from any to any port ...
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3answers
664 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 ...
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1answer
1k views

What is the loopback interface lo0 on Macs?

What is the loopback interface lo0 on Macs? What's the use of it? Does it have any vulnerabilities?
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1answer
612 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 ...
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1answer
996 views

Application Firewall is not enabling pfctl

I have a development environment that uses the Pow webserver. When I initially set it up, it automatically reconfigured the firewall to allow me to connect to my_project_name.dev urls. Last time I ...
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0answers
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How to avoid OS X downloading things while using tethering [duplicate]

When on the road, I would like to use my phone's LTE connection and tether it to my macbook. However, I do not have an unlimited data plan, so I don't want the mac to download a bunch of stuff (OS X ...
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1answer
2k views

ARDAgent.app - what is it?

I sign into a few different email accounts for different family members and I have a few. Im not sure if that is how it happened but What is ARDAgent.app? I found it as being allowed in my Security ...
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1answer
2k views

Port Forwarding on Mac Pro with macOS Sierra

I would like to port forward from my macOS Sierra computer with IP address of 152.1.2.3 to my NAS which is 192.168.2.3. Specifically I would like to access the HTTP web server on my NAS at 192.168.2.3/...
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1answer
55 views

Filter out ARP query from given ether:ip

Let's say on my network there is a hacker who floods my computer with arp messages to associate his MAC address with the IP of the computer I want to reach. It's like he sends the following message ...
3
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1answer
4k views

How to Connect a router to console, using a mac

I just purchased a non-Apple router (a pfSense SG-1000 device by Netgate). As a contingency plan in the event I would forget my web interface password, to then save my bacon, I want to be able to ...