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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24 views

Route/Forward specific traffic to Interface

I want to use a Rasperry Pi as (Wlan-)Router. The Access Point is working so far: I have an Accesspoint with wlan0 (ip 10.10.0.0/255.255.0.0) and wlan1 connected to the internet. Now I want to route ...
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1answer
64 views

Multiple Gateways for Single Subnet

Right, this might be a long one, so bare with me... I have 2 machines, lets call them local1 and cloud1. local1 has 3 Nics: 2 connected directly to cable modems with public IPS (call them eth0 and ...
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1answer
23 views

Why is my ISP box talking to my DMZ host?

I have a setup where an internet connection is available via ISP box, which has a DMZ feature (one of the hosts can be exposed to Internet). The general setup is the following Internet - PublicIP - ...
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0answers
38 views

Docker is only listening locally on a container connected to a VPN

I've just nuked my CoreOS box and am rebuilding the setup as a Ubuntu Xenial (16.04) based docker platform. I'm happy with it so far but I'm now having to re-resolve a problem I already fixed on ...
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1answer
39 views

Forward outgoing traffic for port to another server using iptables

I'm trying to forward outgoing traffic 194.97.114.3:2010 to another server but with no luck. netstat -anup gives me udp 0 0 94.23.28.183:44174 194.97.114.3:2010 ESTABLISHED ...
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2answers
56 views

Ports aren't really getting blocked with iptables [closed]

I'm on Ubuntu 14.04.4 LTS, I'm under attack from some ports, I blocked all of ports except SSH in my own server, I'm doing that by this way: iptables -F iptables -P INPUT DROP iptables -P OUTPUT DROP ...
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0answers
20 views

How do I remove ufw blocked protocol 59 log noise?

The logfile on one of my private servers running Ubuntu 14.04 is being filled with messages of the following form: [UFW BLOCK] IN=eth0 OUT= MAC=[macaddr] SRC=[srcipv6addr] DST=[destipv6addr] LEN=40 ...
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1answer
72 views

What is the FIREWALLD equivalent to IPTABLES -NOTRACK

I recently converted to centos 7 and so far I am beginning to like the simplicity of zones in my firewall structure, however I can't seem to find a configuration parameter for firewalld like the ...
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2answers
35 views

iptables for internet connection sharing

Objective: I am working on an embedded Linux device with the following network configuration. Interface-1: 'wlan0' acts as an access point. Interface-2: 'eth1' connected to Internet. Interface-3: '...
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2answers
58 views

Iptables on a Debian machine, the delete command needs a networking restart to work?

I have a big problem with iptables, this the thing I try to make : PC windows (192.168.1.1) -> (192.168.1.2) PC Linux (192.168.2.1) -> (192.168.2.2) card I want to forward the messages from Windows ...
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1answer
232 views

Huge performance penalty in gbit link with ip forwarding / masquerade through clear VPN tunnel

I have a problem with IP forwarding between my home computer and a remote server (from online.net). My home connection is a 1 Gbit/s FTTH and the remote server has a 2.5 Gbit/s bandwidth. The context ...
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1answer
27 views

Send local traffic from host A:3306 to host B:3306

I'm having trouble making sense of all the iptable examples out there. I simple want all requests from my machine to host A on port 3306 to actually go to host B on port 3306. How can I do this?
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1answer
101 views

Iptables source mac match not always matching?

I have added some rules to my PREROUTING chain in NAT. Usually at the beginning of a new machine joining the network, these matches don't always match correctly? Im using iptables v1.4.21 on OpenWRT ...
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0answers
11 views

iptables rules only work using -m owner

Let's say I have the following rules, since I only want to allow traffic going over my tun0 interface: iptables -A OUTPUT -o tun0 -j ACCEPT iptables -A OUTPUT -j REJECT Unfortunately, the above ...
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1answer
52 views

Open port 8082 on ubuntu for remote access

I need to open port 8082 on my linux box for remote access. I can access the application on port 8082 locally, but not from my other box. Ports 8080 and 8081 are accessible locally as well as remote. ...
0
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1answer
40 views

Except some IPs from rule to not allow internet through openwrt + openvpn when vpn is disconnected

I have the following working setup on my network: A. ISP-Router (connected to inet, internal ip 192.168.0.1 ) <----> B. eth0 - OpenWrt Router (OpenVPN client running) br-lan (bridge eth1 + wlan0, ...
2
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1answer
48 views

iptables REDIRECT and only allow dport

Quick iptables question, I hope. We're running this in iptables: -A PREROUTING -i eth0 -p udp -m udp --dport 57875 -j REDIRECT --to-ports 5060 and then we also have: -A INPUT -p udp -m udp --...
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0answers
41 views

How to create an iptables rule for a specific bonded network interface?

I have a "bare metal" server with a popular cloud hosting provider. (Running Ubuntu 14 in case that's important.) This machine has a network interface that faces the public internet, and also ...
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1answer
22 views

Redirecting outbound traffic to specific IP to localhost

I'm mocking a service, which would in actuality run on 10.1.10.1, and in so doing am trying to redirect the traffic bound for 10.1.10.1 to 127.0.0.1. To create my rule, I'm running iptables -t nat -...
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0answers
15 views

Connection refused with both iptables and firewalld disabled on CentOS. Why? [duplicate]

My Rig Server A with Bacula Dir installed Server B with Bacula Client installed Both uses CentOS 7 Objective. Open port 9102 to be able to access Server B from Server A via Bacula Dir. The ...
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1answer
52 views

Linux server failing to send SYN/ACK after receiving SYN remotely, works locally

Problem: A server process can be accessed by a device on the LAN or by the server itself, but it cannot be accessed outside the LAN (port forwarding is configured correctly as the server does receive ...
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1answer
34 views

Loading Blacklist of IPs from a file into IPTABLES

In a separate file I'm creating a list of IP addresses to be blocked. This file will have IPs added in or removed on a daily basis. I want to "reference" this IP File into /etc/sysconfig/iptables, but ...
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0answers
25 views

Multiple IP failover on VPN PPTP

I have a server at SoYouStart, I ordered an IP failover. I want to setup a PPTP VPN so I could be able to have one connection to the "normal" IP and one to the failover IP I couldn't manage to do ...
3
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1answer
159 views

Create a multi-homed linux load balancer with two internet connections and one LAN connection

OK,... this has possibly been answered, unfortunately, I have not found anything that looks like it might be the resolution. Ive looked at these pages and they have some useful information, but not ...
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0answers
37 views

Configuration SNAT iptables in ubuntu

I have 2 PC be created by VMWARE 1. PC1 (make iptables router): eth0 's IP: 192.168.1.4/24 (network connection is bridged) eth1 's IP: 192.168.2.2/24. (network connection is wmnet9) 2. PC2: ...
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0answers
12 views

How do I get default LXC iptable rules into Shorewall?

I'm setting up a server which will be hosting multiple LXC containers. However, starting Shorewall results in loss network access from within the LXC containers. If I reboot the LXC host and leaves ...
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0answers
84 views

Forwarding UPnP, DLNA traffic via computer to server

I'm about to tear out what is left of my hair with this. I was able to finally see traffic coming through, but not working in full, when using socat but this setup is not ideal. The idea: I have a ...
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0answers
24 views

How can i measure maximum connection, throughput on iptables?

As the title, I have a linux firewall as router. How can I measure maximum connection, throughput on my server? Thanks
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1answer
22 views

DNAT for connecting a subnet via proxy to the internet

DNAT for connecting a subnet via proxy to the internet I want to connect a server in a subnet to the internet via a proxy-server. But I can’t ping a host on the internet (www). Actually the subnet-...
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0answers
35 views

MySQL on Ubuntu. 10061 error on 3306

A fresh install of Ubuntu inside of a Virtualbox with LAMP option selected. I am unable to connect to the server via telnet on this port or via ODBC from my host machine. I can ping and SSH both ...
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34 views

iptables, ufw, and psad - scanned UDP port alerts from router and devices on home network

I have a fresh install of Ubuntu 16.04. I configured iptables, ufw (with gufw), and psad using instructions from https://www.thefanclub.co.za/how-to/how-secure-ubuntu-1604-lts-server-part-1-basics and ...
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2answers
64 views

iptables - access to port 3306 timeout

I cannot connect to mysql from a remote server. I have bind-address commented out but when I add rules in iptables to block other connections the requesting server's connection times out. I tried ...
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0answers
91 views

OpenVPN DNS resolution not working

I'm currently trying to get a simple OpenVPN setup working and I'm almost there, except for a DNS (or routing) issue I seem to be having. The client connects to the server just fine, and I can ping ...
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3answers
94 views

IP forwarding on Linux

I have three machines Source Machine Destination Machine - IP 10.20.30.40 Intermediate Machine - Host server1.test.com Source machine has SSH access to Intermediate machine and Intermediate machine ...
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0answers
118 views

iptables: Redirect traffic from destination IP to new IP

I have a PC client. I like to redirect outgoing TCP connections on port 80 with the target IP 1.1.1.1 to the target IP 2.2.2.2. The full connection should be redirected, which means also the answer ...
0
votes
1answer
24 views

self-curl blocked by iptables

I can't figure out which rule is missing to make this happen... # iptables -Z ; curl -v -k --connect-timeout 2 http://www.myhost.com/ ; iptables -L -v * Hostname was NOT found in DNS cache * Trying ...
0
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1answer
40 views

Firewall rules for ssh, ftp and webapps

I'm running a small cluster with Centos 7 and want the following rules for firewall. Have ssh access from anywhere (i'm going to further configure that from /etc/ssh/sshd_config) Have ftp access to ...
0
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0answers
117 views

Debian iptables load fail

I Have Debian 8 Jessie and I have installed iptables, but it's not correctly. I can add rule just like: iptables -A OUTPUT -s 212.50.128.0/19 -j DROP but it's not working. iptables -L command works ...
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0answers
14 views

From what file/script libvirt inject rules in iptables when I start service libvirtd?

Everybody know that libvirt have his own list of rules for iptables, that he automatically inject in our iptables, after we start service libvirtd Problem: After standard installation of KVM and ...
0
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0answers
42 views

Forward port 80 to 8080 for a specific IP on the network

I have a specific PC on my network running a web service on port 8080. I also have a different machine which acts as a gateway/router, which I configure using iptables rules. What I want to do is ...
2
votes
1answer
102 views

Forward SSH to another Host

I have an ubuntu server which is visible from internet, let's call it "jumper". And this server has this name actually because I need that whenever an user SSH this server, it jumps (or forward or ...
1
vote
1answer
36 views

How does iptables --hitcount collect its values

Im looking at SSH bruteforce prevention with iptables recent module. I would like to know how does the --hitcount collect the value that it will use? Is it bytes, packets, no. of conntracked items or ...
2
votes
1answer
44 views

Postfix not accepting external connections

I have set up a postfix server that works just fine when accessed as localhost. However I cannot make it available from the outside. The relevant configs are as follows: /etc/postfix/main.cf ...
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0answers
46 views

Prerouting with iptables, destination port to DHCP ip

I have an iptables rule that translates requests to the same IP from different internal hosts by changing the source port. iptables -t NAT -A POSTROUTING -p TCP -d 173.32.1.2 --dport 873 \ -m state --...
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2answers
58 views

Redirecting log from /var/log/kern.log to a separate log file for iptables log

I am trying to redirect iptables log to another file. Based upon my reading on the net, I did the following: In my iptables rule, I have rules like: iptables -A INPUT -s ... -j LOG --log-prefix "...
1
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1answer
41 views

Route ipsec to openvpn with iptables

I am not a very experienced user but I do have determination, after a week with no progres it is getting rough. I have two NIC, one facing to the internet and one towards the internal network. Both ...
0
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0answers
29 views

Can access server via SSH/FTP but other protocols won't work

I followed this guide to setup an "Upside-Down Ternet." Everything was fine up until the part where I configured IPTABLES then I lost SSH connection. Now I expected that because I'm messing with ...
2
votes
1answer
66 views

An iptables rule doesn't work

I'm facing the following problem: I want to block the port 8000 being accessed from the network (block all connections except the ones from 127.0.0.1). So to simplify my problem and as a first step, I ...
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1answer
61 views

SAVE IP ROUTE RULES AFTER REBOOT

I have two internet connections from two different ISPs and I need to balance & failover the traffic originating to and from my network between the two ISPs. My settings: FIRST ISP (eth0): 152....
1
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1answer
105 views

Missing firewallD in CentOS 7 VPS

i fresh installed CentOS 7 in a OVH VPS. but when i ran the command firewall-cmd i got this: -bash: firewall-cmd: command not found so i was looking how resolve that and i saw that basically i ...