iptables allow creation of rules to define packet filtering behavior.

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Block all tor traffic from my server

I'm trying to prevent all traffic from Tor exit nodes from hitting my website. I've searched and have attempted a few of the solutions, this is what I've done. I curled the https://check.torproject....
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2answers
280 views

Routing Configuration sending some traffic over VPN

I have a DD-WRT router with an OpenVPN service configured. I'd like to send only certain source IP's over the vpn connection. I believe my current routing table (as seen with netstat -rn) sends all ...
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3answers
131 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
272 views

Forward traffic coming into dummy interface on to another interface(?)

Can I forward traffic coming into a dummy interface on to another interface? Or is it not a real interface at all even? Chain FORWARD (policy ACCEPT 0 packets, 0 bytes) pkts bytes target prot ...
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1answer
91 views

Unexpected netstat output in DNAT conditions

So, here I have a basic setup with SOCKS5 proxy listening on, oh, say 8123 I redirect TCP to the proxy via iptables From iptables perspective everything looks peachy, iptables -t nat -v -L shows ...
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1answer
129 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 ...
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1answer
282 views

Change iptables log format

Is it possible to change the log format of iptables ? I want to add the ssh_client in the log. I have already made an iptables rule for outgoing ssh iptables -I OUTPUT -p tcp --dport 22 -j LOG --...
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1answer
294 views

ubuntu lts and cgroup support in iptables [closed]

I don't understand why Ubuntu community built iptables without cgroup support and what I don't understand if community didn't make it? Maybe Ubuntu use another some way (iptables without cgroup etc)? ...
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450 views

How to match properly against an IP set of type 'hash:ip,port'?

My current setup is that I have a server with several IPv4 addresses. Let's ignore the IPv6 part for now, as the symptoms are identical there. In the firewall rules I'd like to match against HTTP ...
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1answer
41 views

Access to webapp from a different machine

So i have three virtual machines (virtual box). One is the router/firewall. It's running snort + snortsam . This machines runs a webapp in tomcat From this machine I'm trynig to access the webapp i ...
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1answer
95 views

Allow ftp out through iptables

I have been having difficulty allowing ftp through iptables. Right now my ftp looks like this. Chain INPUT (policy DROP) target prot opt source destination ACCEPT tcp -...
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201 views

Valid iptables Firewall on DD-WRT to access Internet on a Virtual Access Point

Device: Linksys WRT54G v5.1 Firmware: DD-WRT v24-sp2 (07/22/09) micro - build 12548M NEWD Eko I use this router as an AP with 2 SSIDs (Private wl0 + Guest wl0.1) and I connect it to a switch (...
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1answer
79 views

What is blocking: Firewall and tcpwrapper?

Is it possible to find whether the firewall (iptables) or tcpwrapper is blocking a connection without accessing the remote server? (Maybe with tcpdump?)
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0answers
484 views

Port forwarding with iptables and PIA VPN for single user

I've gotten a Private Internet Access VPN setup on a Mythbuntu 14.04 machine and I am at wits end trying to get port forwarding working with rTorrent (and ruTorrent). My setup is rTorrent running ...
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1answer
3k views

Fedora 21 Port Forwarding with firewalld (firewall-cmd); how does it REALLY work? Or, does it?

Fedora's ability to forward ports using the apparently "native" networking software, firewalld, appears to continue to be broken beyond credulity. Please note that it hasn't really worked since at ...
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125 views

Linux - iptables - get YouTube streaming bytes usage

How do I get bytes usage using iptables for a particular IP, including YouTube streaming videos? Currently, I am using the following IP tables rules to get data usage by IP address: sudo iptables -I ...
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2answers
137 views

IPtables errors

I am working on a project. I am trying to write iptables rules to control network traffic. I have written some rules. When I try to apply them to the boxes that I am working on I either get locked ...
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1answer
134 views

linux nat different rules

eth0 (192.168.1.0/24) --> wan eth2 (192.168.10.0/24) --> lan0 I use these rules to enable NAT on my linux gateway: iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE iptables -A FORWARD -i ...
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507 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 192....
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101 views

Route wireless LAN through OpenVPN

I am trying to set up my home server to act as an OpenVPN gateway so I can connect to my VPN from any device without installing special software of them. My server is running Ubuntu 14.04. The host ...
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0answers
107 views

How to route vpn traffic over hostapd-raspberry pi

I have a raspberry pi running hostapd and I am able to connect my laptop as a wifi client to the raspberry bi wifi router. The problem is with the vpn traffic, I cant connect to my office vpn with ...
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1answer
31 views

iptables drop policy

Audit my rules I'm ask if I really need of two INPUT policy: iptables -P INPUT ACCEPT iptables -F iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT ...
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50 views

iptables not getting saved ? centos

I am trying to save the iptables, when I run command #service iptables save it says [ok] but when I again open the iptables the rules get revert to default. Can anyone help me to understand this ?...
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1answer
180 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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586 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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1answer
167 views

DDOS defence with iptables

I have server with Debian 6 with a many games servers and sadly, I'm getting ddosed. So, there is my ask for help. I want make solid firewall, where my server will safe.
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1answer
135 views

On a router, what decides if a packet should be forwarded or directed into the router itself?

I'm trying to learn how packet routing works on a linux-based router (OpenWRT in my case) a bit better for setting up a few projects/just-learning. Referencing the below chart, I'll break this into ...
2
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2answers
261 views

Is it possible to have multiple virtual machines with the same (guest) ip on the same host?

What I try to achieve: Multiple virtual machines (virtualbox) on a Debian host which communicate with another server (not with each other or the host). All VMs need to have the same static network ...
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0answers
140 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 ...
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1answer
220 views

Does NAT allow accessing internal network (or router's local interface) from outisde by default?

I am using older SOHO router wl500gP (it is v1 but I think this is not important) with custom Oleg firmware. My topology looks like this: 192.168.3.3 192.168.3.2 NAT 192.168.2.1 ...
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1answer
414 views

iptables allow INPUT from a specific url

I'm using DD-WRT, and can telnet into it to add iptable rules. I'm looking for a rule that will allow IN from a specific address (say, mydomain.com) on port 80 that will point to an internal IP (say, ...
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3answers
293 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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2answers
58 views

output in iptables

I have added the rule to iptables file, however the command does not show it. $ sudo less /etc/sysconfig/iptables Generated by iptables-save v1.4.7 on Fri Oct 24 13:28:48 2014 *filter :INPUT ...
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1answer
283 views

How to enable ping between machines connected in two interfaces?

I have a linux board with two ethernet interfaces as mentioned below. eth0 connected to another linux machine (ad-hoc) eth0 on board 191.168.1.2 connected to Linux machine 192.168.1.3 eth1 on board ...
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1answer
81 views

iptables | redirect from local [interface:port] to local [interface:port]

0 down vote favorite I have two interfaces eth0 (192.168.1.95) and eth0:1 (10.0.0.100) i want all packet for 192.168.1.95:9900 (from any 192.168/24) will be redirect/forward to 10.0.0.100:9900 and ...
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1answer
66 views

How to prevent an application from connecting to a network with iptables? [duplicate]

I have read the manual page of iptables in terminal, but it has complicated syntax and I don't fully understand how to use options like: user, user ID, UUID and so on. Suppose my username is foobar ...
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51 views

Shorewall configuration : providers and LAN

Hi all and thanks in advance for the answers. Currently, I have different providers configured in shorewall. I'll will probably have to change one of them. The problem is I won't have any Public IP ...
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2answers
266 views

Impossible to browse web after configuring iptables

I'm trying to configure iptables on my ubuntu computer. These are my rules: Chain INPUT (policy DROP) target prot opt source destination ACCEPT tcp -- anywhere ...
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1answer
67 views

Email evading my spam filter

I'm having trouble with email evading my Barracuda Spam firewall. I believe the spammers are using my A Record to bypass my MX Record which is what directs email to my Barracuda for processing. How ...
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1answer
116 views

Redirect user once using iptables

I have an access point (Raspberry Pi) running Raspbian (Debian). I need it to redirect user visiting specific website to another one, but only when the user visits the first site for the first time. I ...
2
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1answer
3k views

iptables and RETURN target

I don't understand what the RETURN target does in a iptables command. The doubt comes from this guide where it says: A chain is a set of rules that a packet is checked against sequentially. When ...
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1answer
464 views

Where can I find what the latest iptables version is?

I may be blind but I just can't see what the iptables latest version is. I've checked iptables homepage. I've also searched the internet and nothing.
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1answer
33 views

unable to block out-going traffic

I've run $ iptables -I OUTPUT -j DROP -d [ip address] and found that some processes are still connecting the destination ip I've blocked above: $ lsof -p [pid] it shows: ...
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0answers
155 views

How do you tweak iptables limit rules on openSUSE Tumbleweed?

I have a fresh install of openSUSE Tumbleweed, it is logging a lot firewall related stuff due to my apple devices multicasting to enable airplay. Lines look like: Mar 14 12:45:13 server kernel: SFW2-...
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2answers
39 views

iptables for Asterisk

I am running Asterisk with FreePBX. I would like to log all failed attempts and after a while ban them. Ideally after 3 failed attempts in 1 minute, ban for 1 hour. Is it possible to see if this ...
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1answer
3k views

How iptables tables and chains are traversed

I know linux has 3 built-in tables and each of them has its own chains as follow: FILTER: PREROUTING, FORWARD, POSTROUTING NAT: PREROUTING, INPUT, OUTPUT, POSTROUTING MANGLE: PREROUTING, INPUT, ...
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0answers
199 views

Restrict the maximum number of independent IP connection on specific port at the same time

I set up a server as a socks5 proxy. I'd like restrict the maximum number(1 or 5 or 20) independent IP connection on specific port at the same time. I have searched on google, only see some articles ...
3
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3answers
552 views

monitor bandwidth on interface with tc or iptables

I would like to log a warning message to /var/log/messages file if either ingress or egress bandwidth on eth0 interface is over a certain threshold. I could do this with a script which reads the value ...
3
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2answers
133 views

How to disable network access for a user?

Trying to disable the network access for the user: [root@notebook ~]# iptables -I OUTPUT -m owner --uid-owner tempuser -j DROP [root@notebook ~]# ip6tables -I OUTPUT -m owner --uid-owner tempuser -j ...
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1answer
140 views

Redirect traffic through the server

My task is to redirect traffic (port range) through the server. Here is the schema: Why NAT is not appropriate here: If NAT is set to "Tunnel Server", then all users will be assigned the same IP. ...