A firewall is a piece of software that controls what connections can be made to and from a network.

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What does an empty iptables mean?

I’m using CentOS and when type in the following iptables command: iptables -L -v The output is as follows: Chain INPUT (policy ACCEPT 19614 packets, 2312K bytes) pkts bytes target prot opt in ...
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Deny all incoming connections with iptables?

I want to make some simple iptables rules to deny all incoming connections and allow outgoing. How can I do that?
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226 views

What alternatives exist for Zone Alarm?

I like having Zone Alarm to warn me when programs are trying to phone home / request for updates etc. However, I feel its interface is a little clunky and was wondering if there are any alternatives ...
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3answers
589 views

Safe access to my home network subversion repository

I have a subversion server setup on my home network (windows). I'd like to open a port in my router/firewall and allow access to it from the net. What do I need to do to make sure I don't put both ...
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3answers
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How can one restrict network activity to only the VPN on a Mac and prevent unsecured internet activity?

I'm using Mac OS and connect to a VPN to hide my location and IP (I have the 'send all traffic over VPN connection' box checked in teh Network system pref), I wish to remain anonymous and do not wish ...
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4answers
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Tools to monitor hack attempts/port sniffing

What tools are available that allow me to monitor if someone is using a port sniffer on my computer and/or display any possible hacking attempts? I'm using OneCare, but the firewall information is ...
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8answers
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Internet connection under Windows Vista stops working until reboot [closed]

I have a fairly clean Vista Home Premium SP1 install on my desktop. There aren't many applications installed. My Internet connection always seems to stop working after web surfing for a while - ...
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1answer
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Import Export specific Windows Firewall Rule

How do I Export and Import specific Window Firewall rule (both Inbound and Outbound) ? I can do Import / Export policy but it will use ALL rules not specific rule. Same with Export List, it can ...
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3answers
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How can I get my routers to forward ports correctly?

My network currently looks like this (simplified): Note that Router #2 is connected to the LAN interface of Router #1. This should be familiar to anyone who has seen a standard static-IP setup ...
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1answer
525 views

Rackspace Firewall/Gateway Setup

I have rackspace account and wish to have this sort of setup: Firewall/Gateway eth0 - Public IP (56.X.X.X) eth1 - Private IP (10.X.X.X) Ubuntu 10.10. Accepts connections from the internet and ...
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2answers
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Cookies blocked by router?

My friend has a D-Link DI-524 router that she uses for her home broadband. It's a pretty vanilla setup with the standard firewall settings, DHCP enabled etc. However, recently she has experienced ...
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1answer
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Remote Desktop access Windows 7 system from Windows 8

I have 2 windows systems... Windows 7 (192.168.2.8) Windows 8 (192.168.2.9) Both are connected to WiFi router. They have been assigned address 192.168.2.8 & 192.168.2.9 respectively. I have ...
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Connect and use to multiple networks in Windows 7?

The core of this questions I suppose is "How to I tell Windows 7 which interface to use for each network?" My current set up is: 1) 10/100 cable connected to my corporate network, which is behind a ...
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2answers
496 views

Issue with China's Great Firewall (or other odd networking issue)

We periodically deploy an application to a computer located in China (from Canada). We deploy the changes using Subversion - we're talking a ~100Mb diff. We've noticed that the speeds are good until ...
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4answers
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how to ssh two computers behind NAT and Firewall, without third computer

I am trying to ssh into my Linux box at home. My home is a dorm-style environment - NAT and Firewall with personal laptop running Arch Linux. My work is corporate style Windows 7 - NAT and proxy ...
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2answers
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Stopping PING requests on my home router

I can imagine that somehow not responding to PINGs from WAN would be an ok idea regarding home network security. But can there be any down-sides to this? I imagine games implement their own PINGs, so ...
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9answers
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Force web address to go through HTTPS

At my work, http://twitter.com is blocked, but https://twitter is not. Is there any way to have all programs/browsers access this URL using the HTTPS protocol instead of HTTP? This specifically ...
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3answers
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Configure OSX Firewall to Allow SSH Server?

If I turn on my OSX firewall, ssh is disallowed. If I turn it off, ssh can connect just fine. These are the settings from the ssh host: while I don't know what I'm doing, I figured that giving ...
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6answers
803 views

Standalone firewall + antivirus or combined security tools?

For years I'm using some antivirus software and different firewall. Now every antiviruses have got some firewall features and there are complete "internet security" complexes... and every firewall get ...
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7answers
216 views

Corporate site filter

Alright so my work blocks a bunch of websites for obvious reasons. They even blacklisted logmein.com so thats out. I feel that I am capable of getting all my work done AND keeping up with my warfish ...
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3answers
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What are the most common dangerous domains that I should block?

I am trying to configure my wireless router to block domains that are potentially dangerous to privacy, security, and bandwidth-hogs. Is there a list of domains that I can block at the router level? ...
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4answers
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Multiple web servers behind a single firewall

I have multiple web servers behind a single firewall (SVN, Exchange, etc.). I want to be able to access all of the various servers remotely, but since they are All using the same port (the standard ...
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2answers
128 views

Is hardware firewall useful?

I found out that my PC was attacked, which took almost 99% of my upload internet resource for unknown usage for more than two months. I formatted my PC; update windows and internet security. It should ...
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5answers
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Windows Firewall is blocking Windows Update

I recently uninstalled ZoneAlarm and have decided to use Windows Firewall as my firewall as ZoneAlarm was causing me grief when I was syncing my iphone. Anyway, I've noticed just then that Windows ...
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2answers
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If I use a proxy server, can my computer bypass the ISP?

If somebody is using some kind of proxy server to connect to the internet, does their computer connects to the ISP first and then to the proxy server, or does it connect to the proxy server first and ...
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3answers
147 views

Is there specialized software for testing the security of a computer?

I'm trying to secure my computer against local network attacks for when I'm at university or a LAN party. Although my dad's computer store is also running a Windows Server so it might be handy to ...
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Is there a respected AntiVirus and software firewall app that doesn't invade your privacy?

I recently purchased ESET's AV and firewall software suite. I know it to be a respected app but when reading the license while installing they made it clear that they will collect not only information ...
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What is the best way to restrict network access for one machine on a home LAN?

As an example, I have 3 computers on a home network: Machine A Machine B Machine C What I would like to do is isolate "Machine C", so that it cannot communicate with "A" or "B" and vice versa. It ...
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1answer
2k views

How to append netsh firewall rules, not just replace

I am using a script to set firewall rules in netsh. netsh.exe advfirewall firewall set rule name="Block External IP's" new remoteip="$($ipArray[0])" I thought that set was used so that it would ...
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3answers
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How can I prove (with logging) where a port block is occurring?

How can I prove (with logging) where a port block is occurring? I've set up an FTP site on IIS (windows 7 home) and set up a rule in the Windows Firewall allowing access. The ftp site is accessible ...
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4answers
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Using pfSense, OpenVPN Connects but Still Can't See the Network

I am having an OpenVPN issue. I have a pfSense box at home configured to allow traffic through a VPN tunnel. The client computer is Windows XP Home, behind a standard Comcast connection and a ...
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2answers
680 views

Would there be any problems with DEP turned off?

I recently moved to a fresh Windows 8 x64 system and I learned that my favourite firewall (JPF - Jetico Personal Firewall) doesn't get along with Win8x64 (CRITICAL_STRUCTURE_CORRUPTION errors), but I ...
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How to prevent applications from modifying Windows 7 firewall policy

Basically I've set my Windows firewall the way I want it, but apparently any application can create it's own rule to completely override my settings. How can I prevent this from happening?
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What security changes are necessary when connecting DSL modem directly to PC instead of router?

Windows XP I have a user with a single PC that was connected to the internet via a standard home router. The router is now having hardware-related issues and to save money, they're considering ...
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1answer
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Windows XP Wifi connected but can not access Internet with browser

I have two laptops: Windows Vista laptop which connects fine to Internet (writing this post from it now) Windows XP SP2 laptop which connects fine to Wifi, Router but not Internet When I try to ...
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2answers
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Detect what outgoing ports are bypassed by firewall

My school has a firewall which limits most outgoing ports. There're only TCP/80, TCP/443, TCP/21 allowed. Is there's a way to find out all the outgoing port allowed by the firewall? My current idea: ...
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How to use OpenVPN through a restrictive firewall?

I'm currently in the situation of attempting to setup OpenVPN on a personal VPS, for connection primarily through an overly restrictive firewall. All of the setups mentioned below work when used ...
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1answer
70 views

Is password required for restricted database servers [closed]

I have a dedicated Database server which is have PostgreSQL 9.1. This server has firewall. Only 10.0.0.3 is allowed to connect and access to this server via Firewall. All other requests from other ...
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3answers
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Mac OS X's firewall asks: allow the application “master” network access?

In OS X 10.6.5, the following dialogue popped up: What is this application? What does it do? Cheers! EDIT (to increase googlability): OS X firewall: Do you want the application "master" to accept ...
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1answer
810 views

Safely share a printer in my local network

I have a Windows 7 PC with an attached laser. I want to share the printer over my network, which includes a Wifi router. How can I do this safely without allowing outside traffic to get into it? It's ...
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2answers
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Losing 1/3 of my download speed with my new router, any ideas on how to fix?

I recently replaced a dying D-Link router with a Cisco/Linksys RSV4000. I'm really happy with the device but it seems when my cable modem is plugged in to it I lose 1/3 of my download speed. When I ...
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1answer
163 views

Intermittent connection and “Firewall Blocked” log entries on Cisco DPC3939B with firewall “disabled”

First, I apologize if this question seems to be "all over the place". I've tried to sum it up as clearly as I could, but there are a lot of moving parts, so I've tried to be detailed with my ...
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2answers
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Cannot connect to my mac via SSH

I want to open a connection to my mac (10.8) via SSH. An SSH-server is installed by default on OSX. Remote login is enabled, so the service is running and I can connect to to localhost via ssh. ...
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1answer
329 views

How to block a program from using IPv4?

I have a program that can communicate over IPv4 (TCP and UDP) and over IPv6 (TCP and UDP). I want to block the program from being able to use IPv4. I tried the Windows Firewall: Except it blocks ...
4
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1answer
283 views

Hints on diagnosing performance issue in OpenBSD firewall

My OpenBSD 4.6 pf firewall has started having really bad performance in the past few weeks. I've isolated the firewall (as opposed to the WAN connection, switch, cable, etc.) as the problem, but need ...
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5answers
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Bridge between Wired and Wireless networks for a single device?

EDIT 18/05/2011: Thanks for your answers, bridge mode IS the solution in most cases for this problem, but I can't use it because it breaks my web server. I am now looking at setting up a specific ...
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1answer
587 views

Limiting network connections to specific sites when travelling / tethered (in windows)

I often find myself accessing the Internet while travelling via either (gasp) dial-up or via a very limited data plan on a cell phone. I'd like to make sure that my laptop does not use the network ...
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How to configure Windows Firewall to allow all ports in use by IIS Express

My understanding of this technet article, per the page that brought me there*, is that I can configure the Windows Firewall to allow all inbound traffic on any port being used by a specified ...
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1answer
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Why does NTP require bi-directional firewall access to UDP port 123?

From What are the iptables rules to permit ntp?: iptables -A INPUT -p udp --dport 123 -j ACCEPT iptables -A OUTPUT -p udp --sport 123 -j ACCEPT Also, from the NTP website: ... ntpd requires ...
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If you block an .exe file in Windows Firewall, are you also blocking the .dll files it uses or it needs to be done separatly?

Let's consider this scenario: There's some X software downloaded from the internet with one .exe file and several .dll files. The .exe file is prevented from accessing the Internet by using Windows ...