iptables is the userspace command line program used to configure the Linux 2.4.x and 2.6.x IPv4 packet filtering ruleset. It is targeted towards system administrators. Please, when asking a question about iptables, add the output from the following command: iptables -L -v -n

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4 views

How to turn a UDP feed on and off?

I have a linux application that is sending a stream of UDP packets to a particular ip and port. I need a way of suppressing this packet stream so the packets never reach the network, with the ability ...
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0answers
10 views

Fail2Ban on CentOS 6.5 Never Bans

Environment: *CentOS 6.5 *Fail2Ban 0.8.14-1 *date outputs the correct date Behavior: Fail2ban starts successfully, but does not create iptables blocks after bad SSH login attempts. I'm only concerned ...
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0answers
19 views

IPtables vs bridge vs route (Linux)

IPtables vs bridge-utils vs route I have two network cards in a Linux server and don't know how to make them communicate. After searching a lot I still don't know which method is the one that should ...
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0answers
15 views

transparent proxy with squid3 dansguardian iptables and one nic

I am attempting to filter my home internet connection through transparent proxy (squid3) and dansguardian . I have the following setup: http://i.stack.imgur.com/5Z3DP.png My Ubuntu Server is ...
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0answers
29 views

linux capability - iptables as child process

I have a process that fork-execlp "iptables-restore file.rules". It looks like it doesnt have the permission since i dont see some of the rules not listed like INPUT DROP after the process executes . ...
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1answer
7 views

csf Integrated User Interface not working

i've installed CSF on ubuntu 14.04 using their official install guide after disabling UFW with the following command : sudo ufw disable then i have modified csf.conf with the following values: ...
-2
votes
1answer
36 views

Do cellular network adapters (3G/4G/LTE) have MAC addresses?

We are implementing SSH restrictions by restricting by MAC address in iptables. Without the MAC address restrictions, using an app like iSSH, it's easy to access my server on the go to check on it's ...
0
votes
1answer
29 views

iptables - ignoring -i

In my iptables rules, I want to accept only lo but drop every other interface. but when I execute this command : -A INPUT -i lo -j ACCEPT it is not specifying interface lo but it is accepting all ...
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1answer
8 views

PHP/Ruby captive portal first domain seems cached

I have created a captive portal with iptables I use what many people seem to use : Users can request DNS, packet marked as 99. 99 means no internet else the user does have access. When a user ...
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1answer
46 views

ssh on eth0, everything else on eth1 [on hold]

I wouldn't even consider myself an iptables novice user, so I was wondering if someone could please help me to do this: I want to be able to ssh into one of my servers using the eth0 network ...
2
votes
1answer
35 views

iptables: match only the first packet of established TCP-connection

In my Apache-logfiles I find a lot of entries that contain "GET /w00tw00t.at.ISC.SANS.DFind:) HTTP/1.1" 400 or similar crap. They come from non-RFC2616-connections (HTTP/1.1 without hostname). I ...
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1answer
25 views

I want to proxy only HTTP but I'm not sure what to do with HTTPS traffic

I have a DNS server that resolves all traffic to my Squid server that will proxy all HTTP traffic transparently (it must be transparent or it will drop a invalid url error) which works great. The ...
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1answer
24 views

ip table rules for allow memcache connections

What do the following rules mean? The rules were put in by a sysadmin and seem to be working, but I think there is some redundancy in them. My goal is to allow connections on port 11211. This is on a ...
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votes
1answer
21 views

Port forwarding with iptables -> connection refused

I am trying to redirect requests to my local IP (10.42.42.152) on port 80 to a remote server, e.g. google.com (173.194.113.104:80). The remote server is up, ip_forward is enabled but I only get ...
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vote
1answer
68 views

Port open or not?

I am trying to access the Atlassian Crowd server to configure it, which is listening on port 8095. I can access it from localhost. If I disable the firewall (iptables stop), I can access from a remote ...
2
votes
1answer
40 views

Stateless NAT with CentOS 6

I'm looking to set up the following: ---[IVR 1] | (internet)----[CentOS box]---+---[IVR 2] | ...
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0answers
14 views

tun0 not listening traffic on a simple vpn example

I tried to setup a simple vpn test server on Ubuntu 12.04, called ToyVPNServer. The guide is simple and I take test for days but still cannot get connected. The inspection result is showing the issue ...
0
votes
1answer
15 views

make specified ip log filtering from port mirroring input with iptables [on hold]

I have difficult to create an iptables rule of traffic coming from a switch that is configured as port mirroring. I checked if the traffic from my switch is sent with tcpdump -> Tcpdump detects ...
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0answers
32 views

Reroute outgoing port through other server

I want to run a xmpp-server on another IP than the A-record of the domain points to. +--------+ +--------+ +--------------+ | xmpp | -----> | web | -----> | internet | | ...
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1answer
35 views

Iptables working without configuration

I am currently going to port a Red Hat 6.4 machine and I need its firewall configuration, but something is going on. iptables -L shows a list of rules as expected, but at the same time I can't find ...
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0answers
10 views

Can't connect to Tomcat

I an new to Tomcat and having some problems - I have installed Tomcat 7 and it is running and set to use port 8080 in server.xml. I have opened port 8080 in iptables (and saved iptables) but I cannot ...
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0answers
4 views

Open ports for Age of empires in ubuntu router using iptables [migrated]

The purpose of this question is to learn how to correctly use iptables. As I am currently living in the dormitories in the University and I am using a small netbook as a router to provide wifi in my ...
1
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1answer
23 views

iptables + postfix cant send email

Recently my host provider sent me a letter about some sort of attack from my server. I'm not into security so i found some tutorial and closed all unused ports with iptables. Here is my iptables ...
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1answer
36 views

Something is filtering 27017 port even then firewall is not working

Good day, i' trying to move mongodb database to separate VPS from application, but VPS was pre-configured not by me. I have instance with running mongodb on 27017 port: COMMAND PID USER FD ...
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votes
1answer
40 views

ssh tunneling not working due to strict iptables

my iptables are set so that I can only allow ssh connections. I tried ssh tunneling and I can connect to my sever, but after when I try using my server as a proxy on firefox, pages try to load ...
0
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1answer
60 views

Iptables drop outgoing HTTPs GET request matches string in payload [closed]

I'm using CentOS 5.8(final), kernel 2.6.18-308.8.2, iptables v1.3.5 I want to block a HTTPs POST/GET request to outside which matches a string (defined as ABCxyz) in the POST/GET payload. I tried to ...
0
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1answer
20 views

QEMU guest can access HTTPS sites, but not HTTP

So I'm configuring a QEMU guest on my Debian Wheezy server, using virt-manager. As guest I've installed Ubuntu 14.04.1 server. The server contains the following iptables rule: iptables -t nat -A ...
0
votes
1answer
25 views

Data only seems to go one way on ethernet over usb connection [closed]

I have a router+modem combo connected via ethernet to a raspberry pi (this part works fine) The pi has a usb wifi device plugged in, and runs hostapd, does NAT and provides internet to a household. ...
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0answers
36 views

Iptable rules are automatically removed [closed]

In my rhel 6.5 server I have configured a zimbra mail server and squid proxy server. I have added some iptable rules and saved them and also added to run levels using chkconfig command. But the rules ...
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0answers
7 views

Special type of DMZ? [migrated]

So I have a standard modem-router setup all great to go, my Modem gives an IP Address from my provider via DHCP according to my Mac address. All is good. However, I now want to expose a new virtual ...
0
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0answers
29 views

Why HLS streaming bypass connlimit iptables rule?

excuse me, i have this situation: I need to set limits to the simultaneous connections to a server to enable only X number of viewers of a stream at any time. To make the video streams we are using ...
0
votes
1answer
104 views

Fail2Ban - Iptables - Set does not exist

I have a very strange problem with fail2ban/iptables. Something is not working right, but I can't figoure out what. I have added this conf & and filter for fail2ban: [wordpress-register] enabled ...
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0answers
18 views

Will an inbound iptables rule in ddwrt on port 443 break https? [migrated]

I want to run a vnc repeater service on my home ddwrt router. Due to the possibility of friends/family asking for support in unknown network environments, I'd like the host-repeater application to run ...
1
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0answers
36 views

shorewall can'T start: UNTRACKED state requires Raw Table in your kernel and iptables

I'm trying setting up my firewall and installed and configured shorewall. Unfortunately I tried to directly configure iptables first, but this didn't work. When I start shorewall, I get this messages ...
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votes
0answers
9 views

iptables - remote domain to local [duplicate]

I have a problem and i would ask u for help: We have local www server with example addr 192.168.1.2, remote domain site.com.pl that is pointing at our external IP (let's say 123.124.125.126) and the ...
-1
votes
1answer
19 views

Application protocol-based port forwarding/redirection [on hold]

I need to split traffic on port 80 between HTTP and non-HTTP, and internally forward HTTP traffic to a port nginx will listen to, and non-HTTP traffic to port 22. Does anyone know of a piece of ...
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0answers
66 views

TCP packets not reaching app, iptables dropping?

We are occasionally, but not consistently, experiencing a weird network stack issue. Rebooting the server in question clears it up. It happens as follows (gleaned through tcpdump on the server): ...
0
votes
0answers
27 views

Virtual Interface IP on cpanel not working

I am new cpanel and whm world !! I have a physical server in my office ,configured with WHM . Setup : Mail server Server is inside LAN,Total 13 IPs configured eth5 192.168.100.254 #Main IP ...
0
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1answer
51 views

Can't open ports to ouside

I need to open my webserver to internet. I have no idea whats wrong with my config but no ports opened to internet, and server does not respond to ping. I have debian squeeze webserver with following ...
1
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2answers
37 views

Allow only IPSEC outgoing traffic to a port (using IPTABLE?)

Problem: I've a situation where IPSEC server and the target server (Say http server) happens to be the same machine and I need allow ONLY the traffic coming through IPSEC server to have access to a ...
-1
votes
0answers
45 views

ubuntu 12.04 vps server pptp setup not working, openvz host has ppp/pptp enabled

I'm trying to setup a vpn between two servers with pptpd on one server and the client running on the other. I am using ubuntu 12.04 on both server vps's. I had the one vps provider enable all the ...
0
votes
0answers
20 views

NAT Traffic via my instance in Microsoft Azure

I'm working in Azure IaaS Environment I have a private network 172.16.0.0/16 in which I have few linux instances running (172.16.0.1-5) My instances are accessing the public internet on port 80 (so my ...
0
votes
1answer
41 views

Forward traffic to VPN

I have several servers I want to put on a VPN. I've set the VPN up with OpenVPN and that's working fine, each machine can access the other servers on the VPN. My issue is I would like to somehow ...
1
vote
2answers
51 views
+50

iptables, ICMP and RELATED

I am using the following simple iptables rule that accepts related packets: -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT I am letting ICMP echo-requests pass with this other rule: ...
1
vote
0answers
41 views

Shorewall: DNAT to IPSEC tunnel zone not routing correctly

I have a ipsec tunnel working that gives access to a 192.168.4.0/24 lan. It is working fine and I can access hosts on the other side without problem: # from fw and lan hosts: # ping 192.168.4.44 PING ...
0
votes
1answer
27 views

How can I tell what's happening to my packets?

I'm trying to bring up a little box on my network. I just reflashed the firmware and it's supposed to come up as 192.168.1.1 by default. My router is a DSL modem at 192.168.0.1; it usually uses a ...
0
votes
2answers
56 views

My ubuntu server won't allow loopback wget

I have the following rules on my Ubuntu Server 14.04: #!/bin/sh # Flushing all rules iptables -F iptables -X # Setting default filter policy iptables -P INPUT DROP iptables -P OUTPUT DROP iptables ...
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votes
3answers
37 views

Changed SSH port but iptables refuse

I just changed my SSH port from the default 22. Now, I cannot access it anymore, my thought would be the firewall. I already added the new port to the iptables then do sudo iptables-save. However it ...
1
vote
1answer
127 views

Duplicate iptable rules

I have this iptable rules: -P INPUT ACCEPT -P FORWARD ACCEPT -P OUTPUT ACCEPT -N fail2ban-ssh -A INPUT -p tcp -m multiport --dports 22 -j fail2ban-ssh -A INPUT -p tcp -m multiport --dports 22 -j ...
-1
votes
0answers
24 views

Blocking all the traffic from an interface and redirecting it to TOR [duplicate]

I've set up a OpenVPN VPN server which allocates 10.2.4.X IPs (interface tun1) to clients. Server's IP is 10.2.4.1. Tor has TransPort 8118 and DNSPort 5300 listening, obviously, on 10.2.4.1. These ...