A networking program that controls the incoming and outcoming stream of data in a computer.

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Full network logging via linux firewall ( iptables )?

How truly enable full network logging via iptables? There is an option --log-prefix to add a tag to log entries. But the log entries don't show all complete packets. What a grand way to enable full ...
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1answer
197 views

IPtables : Limit number of new ssh connections per minute

I need to ensure on my server that maximum new ssh connections per minute are not more then 5. sudo /sbin/iptables -A INPUT -p tcp --syn --dport 22 -m connlimit --connlimit-above 5 -j REJECT Above ...
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504 views

openwrt firewall - block a set of ip addresses from internet access

I'm running OpenWRT Attitude Adjustment r33556 / LuCI Trunk (trunk+svn9325) on my WNDR3800. I would like to configure my firewall to: Only allow a specific range of IP addresses to access internet, ...
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34 views

Custom firewall zone

Is there a way to create a custom zone using firewall-cmd in fedora. They give you some predetermined zones, but no way to create a custom zone with a custom name and add rules to that zone. Is ...
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1answer
91 views

Linux GUI to track connections made from/to this computer

Is there a GUI to track any socket connection sent to this computer and which program that initiates it? Also if possible track any incoming connection sent to this computer and which program that ...
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1answer
136 views

Intercept incoming TCP/IP packets on Linux and perform NAT

I want to make a decision of what computer is behind the firewall sending the packet. Imagine I have 2 PCs behind the firewall and I want to, based on (my algorithm), make a decision at the firewall ...
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1answer
1k views

Creating UFW rule to allow application to use dynamic ports

I am currently trying to get a Google Chromecast device to work through my Ubuntu 13.04 based computer. Currently, the Google Chrome extension shows "no devices found" as long as my UFW firewall is ...
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2answers
513 views

Missing iptables file on directory /etc/init.d/ (Fedora 17)

Is the iptables file in Fedora 17 moved from /etc/init.d/ to /etc/sysconfig/? I need do some patching to the iptables file to solve the firewall problem (Setting chains to policy ACCEPT: security raw ...
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167 views

PF and types of NAT(Network Address Translation)

As you know, at least 3 types of NAT are used. Of course i need to two types of them.DNAT and SNAT. DNAT : hiding server behind NAT, SNAT : hiding your client behind NAT. Question: I read a quick ...
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3answers
421 views

what is the required ports to be opened on the firewall?

Currently I'll be installing one AIX server behind a firewall, I just asked to open port 443 to use the SSH protocol to access this UNIX server. I already changed the default ssh port to be 443 ...
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57 views

how to list blocked connections events by the firewall?

So, I used firestarter that had logged blocked connections events with some useful details (but it is not being updated and I found somewhat unsafe as any moment we could click to deactivate the ...
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1answer
481 views

Looking to build a low powered linux based firewall

I am looking to build a low powered linux based firewall. I need a reliable piece of hardware that has two (2) LAN inputs and a built in wifi. Fanless and low power system. any recommendations? Any ...
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1answer
70 views

Is there any tools which can be used to make ports available from any firewall network?

I have been testing my application which has TCP/UDP ports for peer to peer with the help of server signalling commands for making communication, that works when I have Public IP or Lan IP and not ...
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2answers
98 views

what is `firewalld --nofork`

I carelessly killed the following process root 470 1 0 Jun06 ? 00:00:13 /usr/bin/python /usr/sbin/firewalld --nofork Is there any consequence from killing the process? Are there ...
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1answer
50 views

RapidIO packet filtering in Linux

I was wondering if there is support in Linux Kernel for RapidIO packets filtering, something similar to iptables, but based on RapidIO header?
2
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1answer
208 views

ufw firewall rules for security.debian.org

What is a practical way to manage a whitelist of firewall outgoing connection rules for http://security.debian.org (on a server that blocks all outgoing connections by default)? My understanding is ...
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3answers
691 views

How to setup transparent firewall using ArchLinux

I am trying yo setup a Transparent Firwall using ArchLinux. My setup looks like this: (ISP, IP: 10.90.10.254) \ \ \ (eth0-> ip: 10.90.10.1 gateway: 10.90.10.254) +-----------+ | ...
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77 views

In Linux is there any tools or package which can do STUN TURN ICE NATs and firewalls break end-to-end connectivity

In Linux is there any way to do this NATs and firewalls break end-to-end connectivity with existing package or tools? e.g: close source cant use it for free ...
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1answer
120 views

Iptable rule to ssh over the internet

I've a server abc.example.com and a remote desktop zzz.example.com. I'm using SSH over a custom port, say, 6789. Whenever my firewall is off, I'm able to connect to the server successfully. But, as ...
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1answer
2k 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
157 views

Possible sftp connection behind a router that is impossible to open any public ports except some standart ports like http?

I want to ask about the problem that I have with my office computer. I cannot reach the router so I cannot redirect any incoming requests to my PC. I have to get a huge file from another computer on ...
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43 views

Firewalld SELinux

Is there any way to better explanation firewall-cmd than the one given in Fedora18 wiki. I am trying to convert iptables to FirewallD in cmd line without GUI but cannot find a decent example or ...
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135 views

PGP keyserver and proxy firewall issues

I am not sure this is a Linux question directly ... I use Arch Linux which uses package signing. This requires me to download a set of pgp keys with the pacman-key program. This works off the ...
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8k views

How to check whether firewall opened for a port but not listening on the port

We will be deploying a new application to a Server and the application will be listening on port 8443. We have asked Network team to open the firewall for the port 8443 on that server before deploying ...
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1answer
92 views

Adblock rule to block g+ / twitter / etc. [closed]

Looks like this rule works to blocking facebook domain, when not visiting the facebook domain (ex.: "like/share" etc. buttons on other pages then facebook): ! don't allow facebook outside facebook.. ...
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iptables rules not reloading on CentOS 6.x

I have one single ipset added to my iptables on a CentOS 6.x box and this rule is lost when the machine reboots. I've found this answer showing how to make a Ubuntu system reload the iptables rules ...
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1answer
381 views

How can I disable UFW logging for a specific event?

My router sends out multicast packets in regular intervals that are blocked by UFW's standard policies. These events are harmless but spam my syslogs and ufwlogs. I can't change the router's behaviour ...
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3answers
551 views

Linux stack for a home network firewall/proxy?

I've got a generic home 'network' where my ISP supplied modem acts as router with a software firewall built-in. My PCs connect directly to this router to access the Internet. I want to place a box in ...
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3answers
212 views

Packet analyzer to intercept and filter incoming traffic before any client app

I am curious if most Linux distros make it possible to intercept incoming network traffic as soon as it enters the system and filter its content based on some rules before any other client can use it ...
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196 views

Port Forwarding Between 2 Internet Machines

Here's my scenario: Setup There are 3 machines: A: on the internet : has ip (a.a.a.a), has port pa open B: my server / gateway : has ip (b.b.b.b), has port pb open C: on the internet : has ip ...
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2answers
313 views

Is it possible to whitelist a specific program in iptables?

Is it possible to allow all traffic for a specific program in iptables? Otherwise using nmap and a strict iptables configuration at the same time seems impossible.
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1answer
23 views

EST/REL or REL/EST in iptables firewall scripts?

-A INPUT -p tcp -m state --state RELATED,ESTABLISHED -j ACCEPT every Firewall rule usually starts with this. Q: Does it matter that is it RELATED,ESTABLISHED OR ESTABLISHED,RELATED?
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908 views

What does this firewall record mean?

Running iptables -L -n gives me the following info: Chain IN_ZONE_work_allow (1 references) target prot opt source destination ACCEPT tcp -- 0.0.0.0/0 ...
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1answer
168 views

How to allow access to web only through proxy?

I have a machine with Linux Slackware 13.37. Is it possible to configure iptables, so the users will be able to access web only through squid? The direct access through the browser will be blocked. ...
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1answer
688 views

Help to understand Iptables Forward chain with DNAT

I have one server where iptables configured with all chains DROP in filter table eth0 :- 10.0.0.2 [ Intranet assume as LAN ] eth2 :- 172.16.0.2 [ External clients assume as WAN ] Now What I am ...
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1answer
173 views

IPFW Port Forwarding

This is my situation: I want to connect to an OpenVPN server from my office (we're using a proxy, only ports 80 and 443 are allowed). Server IP address is: 176.31.250.232:843 My static IP address ...
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1answer
4k views

How to re-enable iptables on Fedora 18?

FirewallD is the default firewall in Fedora 18. I have been using iptables for quite some time and have a custom configuration which I need for logging of ip traffic. I am not used to the new ...
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2answers
2k views

iptables blocking from internet side on eth1?

How to use iptables to deal with two Ethernet ports? eth0 port for LAN use (192.168.1.50 Private IP). eth1 port is connected to the internet via cable modem (80.0.xxx.xxx public IP). ifconfig ...
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2answers
126 views

Fedora Firewall no option as of yet

I need a firewall because I was decade long user of internet security suites on windows. I am not a professional of networks or anything but a student who just needs to block unblock running ...
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1answer
920 views

What to use for firewall testing (port opened or not)

so... we know that we can test that if a port is open on the firewall with: telnet SERVERIP PORT ..but afaik there are services that can't be tested with telnet, because ex.: telnet doesn't know ...
2
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1answer
204 views

How to configure OpenBSD pf to only allow inbound from given countries?

I have an OpenBSD 5.2 box what's running a webserver on port 80 and an SSHD server on port 2222. How can I configure OpenBSD's pf to only allow connections from given countries to port 80 and 2222?
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1answer
255 views

How to interpret and react to Shorewall log?

I see the following pattern in every 2-3 sec, for several minutes in syslog: Shorewall:net2fw:DROP:IN=eth0 OUT= MAC=aa:bb:cc:dd:ee:ff:gg:hh:ii:jj:kk:ll:mm:nn SRC=12.34.56.78 DST=98.76.54.32 LEN=60 ...
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1answer
241 views

Can I limit connections per second for certain UserAgents using UFW?

GoogleBot is hitting my server hard - and even though I have set the CrawlRate in Webmaster Tools it is still hiking up the load on my server and slowing down Apache for the rest of the normal web ...
3
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1answer
2k views

How to understand why the packet was considered INVALID by the `iptables`?

I set up some iptables rules so it logs and drops the packets that are INVALID (--state INVALID). Reading the logs how can I understand why the packet was considered invalid? For example, the ...
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1answer
280 views

Firewall/routing rule in Centos for this setup

I have two ethernet interfaces, namely eth0 and eth1. I want to implement an advanced routing rule but I am totally new to firewall/routing rules in CentOS. Here is what I am trying to do: Both my ...
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502 views

Allow incoming connections from Google Translate only

I have a small web server running on port 80, and I'd like to allow only Google Translate to have access to it. First I tried running dig translate.google.com and dig translate.googleusercontent.com ...
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3answers
600 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 ...
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1answer
1k views

nmap shows me that one service is “open|filtered” while locally it's “open”, how to open?

I have a Quake 3 server. And it's launched successfully. The problem is that no one can connect to that server. I am running: nmap -sU -p 27960 hostname and it's showing me that it's state ...
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3answers
8k views

How to block https facebook site using iptables [duplicate]

Possible Duplicate: iptables to block https websites I am using Zentyal Os as a firewall, it working fine like blocking http sites and but I am not able to block https facebook site. My ...
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119 views

Perform Cisco's DNS Doctoring on FreeBSD

How to perform a change in the DNS response from a DNS server to be a different IP address than the DNS server actually answered for a given name? ...