A firewall is a program that controls the incoming and outgoing network traffic on a system. Use this tag for all questions related to firewall configuration and operation.

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iptables to block all websites

I have Debian 7, and I want to block all websites in my computer, unless my email, using IPTABLES or others firewall. How can I block all website, include http and https too. How can I do this?
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2answers
55 views

Error when redirecting ports with iptables: No chain/target/match by that name

I am trying to redirect all incoming TCP connections, originally to port 80, to port 8090, because I am running Confluence in 8090 and I want to avoid it running as root, which is a requirement to ...
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1answer
54 views

Blocking or forwarding packets as access point

I set up my Pi 2 as a wifi access point following this tutorial. I'd like to implement a rudimentary QoS, according to the DSCP field in every packet's header. That means, blocking packets using low ...
3
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1answer
149 views

Which ports should I open for apt-get to work?

I installed Webmin, and then set up the firewall like this: INPUT SSH port ALLOWED Webmin port ALLOWED HTTP port (80) ALLOWED DROP EVERYTHING ELSE FORWARDING no rules OUTPUT no rules If I remove ...
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1answer
17 views

ufw rule deny default outgoing

I want to deny all outgoing traffic by default, except ssh connections. I added this rules: ufw default deny outgoing ufw allow ssh Then I restarted the firewall by: ufw disable ufw enable ...
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1answer
32 views

Block outgoing connections to certain IP using PF

Can someone give me a hint on how to setup a basic deny rule whenever any TCP request is sent to a specific IP address? I am using the PF packet filter. Any help?
4
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1answer
1k views

Outgoing firewall application similar to Little Snitch for Mac

Is there a Linux application similar to Little Snitch? Little Snitch is an outgoing firewall that temporarily blocks outgoing network requests until the user decides whether to allow the connection or ...
3
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1answer
169 views

How to combine iptables rulesets

Say there are several iptables scripts (run at boot time), all of which run something like iptables -A ... to add rules. I'm thinking this could be improved, turning all those shell scripts into text ...
0
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1answer
25 views

Block outgoing connection from running process

I have an java application that I have been developing. I use a external db server that I can't control. I want to simulate connection error to it, but I'm unable to do it. I have tried to use ...
2
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1answer
54 views

How to Mark Traffic using IPtables?

I'm trying to mark traffic, How shall I write following code in terms of IPtables? /ip firewall mangle> add chain=prerouting src-address=10.1.1.1/32 action=mark-connection \ ...
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2answers
1k views

NAT and source IP filtering in PF, using OpenBSD >= 4.7

I just read a book about PF (The Book Of PF, No Starch), but there's one question not answered by it. If I have a gateway machine using two interfaces, $int_if and $ext_if, and I NAT the packages ...
5
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1answer
3k views

Installing pfSense firewall on an SSD

I was looking at creating a home firewall running pfSense (as I could not get IPCop to boot properly on my hardware). Doing a little research, however, I have some concerns with installing it onto an ...
2
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1answer
493 views

iptables Port Forwarding — no service with the port

I have setup a network as in the image below: Firewall (FW) running CentOS 6 has two physical interfaces with subinterfaces: eth0:2 — 10.100.1.78/25 eth0:3 — 10.100.1.79/25 eth3 — 192.168.0.21/24 ...
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0answers
22 views

Can I inherit iptable rules on/under windows? [migrated]

Don't really want to purchase a VPS just to test some iptables stuff for my gameserver. Was curious if it's possible to load up debian on vmware player and install nginx, nodejs, mysql, etc (which is ...
0
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1answer
45 views

How to block telnet using iptables command

I am trying to block telnet on my server but I have failed to do so. I have added following firewall rules in INPUT chain of filter table for the same. INPUT CHAIN(filter table): <some other ...
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2answers
53 views

iptables configuration - ssh connection only from a remote network

I'm trying to configure Iptables of a server in order to permit SSH incoming connections only from a certain network. by the way this is the rule chain : # Drop anything we aren't explicitly ...
11
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1answer
11k views

Difference between SNAT and Masquerade

I am confused what's the actual difference between SNAT and Masquerade? If I want to share my internet connection on local network then whether should I select SNAT or Masquerade?
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0answers
38 views

Why is my laptop being blocked from connecting to a PPTP VPN server?

I have a fairly simple network at home Internet --> Modem --> Linux Router --> Switch --> Laptop The problem: There is a PPTP VPN server at work that I need to connect to from home. I configured my ...
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1answer
54 views

to allow certain ips and block all other connections on AMAZON EC2 ubuntu 12.04

How do I allow certain IPs and block all other connection in iptables on AMAZON EC2?
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1answer
76 views

is iptables broken on my raspberry-pi? how to fix?

I am getting some person(s) trying to brute force my ssh, from multiple ip addresses (small sample) : May 22 19:50:02 rpi sshd[1272]: pam_unix(sshd:auth): authentication failure; logname= uid=0 ...
2
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2answers
81 views

How can I allow SSH and SMTP only using IPTables?

I've got a raspberry pi set up to send me periodic emails. As it's connected to the internet 24/7, I need IPTables set up properly. I want to allow incoming SSH and allow emails to send out on port ...
11
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3answers
14k views

How can I block a range of IP addresses with an Amazon EC2 instance?

I know a certain range of IP addresses are causing problem with my server, 172.64.*.* what is the best way to block access to my Amazon EC2 instance? Is there a way to do this using security groups or ...
6
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2answers
13k views

IPTables - Port to another ip & port (from the inside)

I currently have a NAS box running under port 80. To access the NAS from the outside, I mapped the port 8080 to port 80 on the NAS as follow: iptables -t nat -A PREROUTING -p tcp --dport 8080 -j DNAT ...
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1answer
33 views

Help about CentOS 7 apps & Driver [closed]

I'm using pc for several years but never tried Linux so I'm quite noob in this field. I'm using Autodesk maya, Nuke & will learn houdini very soon. I found that linux works faster for this apps so ...
0
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2answers
44 views

Determine what port OpenSUSE firewall is blocking

I am having a problem with the WebStorm IDE in that I cannot use its built-in FTP capabilities probably due to my OpenSUSE (Tumbleweed) firewall blocking some needed ports. I am assuming that because ...
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1answer
34 views

Linux IPTables - Ignore Range of IPAddresses

I am currently modifying some of my IPtables rules on a public server and have run into a bit of a dilemma. The goal is to do the following: Rate limit the amount of SSH connections that can be made ...
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0answers
18 views

equivalent of iptables rule in ip6tables

I m newbie in the iptables. I have the following iptables rules in the source code of a project iptables -t mangle -I PREROUTING ! -i br0 -p TCP --dport 45 -j MARK --set-mark 0x1000 iptables -t nat ...
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4answers
2k views

How to do domain filtering in Linux?

Preferably something similar to iptables. Basically, I want to do domain filtering/whitelisting/blacklisting like I would with IPs in iptables. Are there any recommendations on how to do this?
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37 views

firewalld isn't blocking/dropping ports for ports mapped from docker containers

I have firewalld installed and running on my machine. here are my active zones # firewall-cmd --list-all-zones ... drop (active) interfaces: enp2s0 sources: services: http https ssh ports: ...
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2answers
621 views

FreeBSD ipfw keepstate vs setup keep-state

A lot of examples where people are using keep-state with setup together. For example: ipfw add 1 allow tcp from any to me 22 setup keep-state Because of setup, this rule will allow only SYN ...
0
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3answers
63 views

How does the iptables work with IPv6?

I would like to set up a firewall on Linux Debian for IPv6. It is important to use iptables for me. I have tried to change the ipv4 folder to ipv6. How can I set up iptables for IPv6?
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1answer
31 views

package from IP arrives at certain port => open portrange to IP for x seconds

I have been toiling with an issue on iptables: I am trying to make a portrange open to a specific IP for x seconds/minutes as a result of a single packet being sent to a specific port. Not exactly ...
0
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1answer
285 views

How to configure Centos 7 firewallD to allow docker containers free access to the host's network ports?

I have docker installed on CentOS 7 and I am running firewallD. From inside my container, going to the host (default 172.17.42.1) With firewall on container# nc -v 172.17.42.1 4243 nc: connect to ...
2
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1answer
89 views

NFS Port Blocking Firewall Issue

I am a little stumped on this one and maybe I have been staring at this for too long...but I cannot get my Mac (10.10.3) machine to connect to my Oracle Linux 7 (CentOS/RH 7) server with its firewall ...
14
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1answer
6k views

Is it better to set -j REJECT or -j DROP in iptables?

There's an example of iptables rules on archlinux wiki: # Generated by iptables-save v1.4.18 on Sun Mar 17 14:21:12 2013 *filter :INPUT DROP [0:0] :FORWARD DROP [0:0] :OUTPUT ACCEPT [0:0] :TCP - ...
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0answers
71 views

Disable networking only inside of a single terminal

I want to run a command in the terminal to disable networking, just in that terminal. How can that be accomplished? I'm running OSX. Note: I only want to disable the networking in that terminal. ...
2
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2answers
594 views

Is there any PF log parser for FreeBSD

I am runing FreeBSD 8 stable with PF as firewall, I am looking for any tool for parsing PF log's.
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0answers
83 views

How to create a rule on IPCop firewall for bittorrent trafic to work properly?

I've been trying to use my favourite torrent client (µTorrent) after setting up my IPCop (last update 2.1.9) and it warned me that my router/firewall was blocking the traffic and that I had to open a ...
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0answers
63 views

Redirect all ARP traffic from eth0 to eth1

I would like to redirect ARP traffic, but I'm struggling with arptables and ebtables. I have 2 interfaces: eth0 10.10.10.25 eth1 10.10.10.20 Both in 10.10.10.0/24 I want to redirect the ARP ...
1
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1answer
48 views

Unable to access another server over local network on Digital Ocean

I have two servers. Let's call them A and B. Both are running ubuntu server 14.04. B runs percona server. Now I do not have any firewall set-up on either servers still I am unable to connect to server ...
2
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1answer
54 views

Close the neccessary Ports [duplicate]

I am using Linux Mint and I am newbie. Someone is trying to access my computer via my MAC Address and open port. I have some questions: I know that there are different type of port like TCP and UDP. ...
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40 views

Forcing google/youtube safesearch on Ipfire

I use IPFIRE firewall os and even though it has a force safe search feature it doesn't seem to work. Would there be any other way to force this feature as I cannot seem to. Create a new cname in ...
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0answers
168 views

How can I redirect internet traffic from local to proxy server with ip tables (DEBIAN 6)

So i made topology as shown in figure. Router have 3 interfaces like this: eth0 to internet side (with ip 192.168.1.10/24 gateway 192.168.1.254/24). eth1 to server-PC side (with ip ...
0
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2answers
108 views

Connection Timeout for ssh connection depending to the ip location?

I have a machine where I can connect it using ssh from different networks. But when I have moved to other country I have not be able to connect it. What may be the cause? I am able to ping the server ...
2
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1answer
34 views

Are there any loopholes in IP restricting sshd?

Say that i want to only allow username/password logins on my private network, but restrict all external sources on to key/cert login. I would do something like this: RSAAuthentication yes ...
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0answers
52 views

CSF not blocking port when removed from csf.conf

I have removed VNC port 5901 from the csf.conf configuration file and executed a csf -f a csf -x and a csf -e to flush and restart CSF. There is a vncserver running on port 5901 and when doing an ...
0
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1answer
61 views

mount times out with iptables --policy OUTPUT DROP

I previously ACCEPTed all output traffic by default. Recently changed the policy to DENY output by default, only opening ports needed for server/application functionality. When I tried to mount a ...
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0answers
153 views

CentOS as home network router: IPTables Port Forwarding failure

I have currently set up a home server with a CentOS 6.6 installation on it. The server has two NIC interfaces which I'm using it as my router and DHCP server. Here's a diagram showing the network ...
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3answers
85 views

how to automate creating firewall rules?

There is a complex live system - few vlans. In each of them there are linux servers, and on every server there are services. Services connect together - for example service http on host A connect to ...
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4answers
1k views

Can't add large number of rules to iptables

I made a very simple bash script (echo at start, runs commands, echos at end) to add approx 7300 rules to iptables blocking much of China and Russia, however it gets through adding approximately 400 ...