iptables allow creation of rules to define packet filtering behavior.

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226 views

Debian 8 - Update Iptables on boot

I am in the process of porting my "configure openvpn server" from ubuntu 14 to debian 8. So far it works well except for this section: # Set up iptables to forward packets for vpn and do this upon ...
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1answer
35 views

Debian network disappearing

I'm running Debian v8 (systemd purged and systemV installed ... works fine). It is a clean installation (Debian v7 used to be on this machine) The harddrives failed after numerous power failures on 1 ...
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0answers
45 views

Iptables - Limit SMTP output traffic

I'd like to limit the output smtp traffic of my server (Debian). For example : only 10 mails per seconds. I want to use Iptables for this purpose. I tried : iptables -A OUTPUT -p tcp --syn --dport ...
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1answer
58 views

NAT box with multiple internal and external interfaces

Similar questions have been asked before but my setup is a little different and the solutions to those questions are not working. A have a CentOS 6 server running iptables with 5 interfaces: eth0: ...
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0answers
280 views

Is it possible to throttle upload bandwidth per `IP` basis using `tc`, `htb` and `iptables` ? (Download limitation not required)

Problem I've searched internet like anything but couldn't find much about limiting upload. The solutions given are not limiting IP basis like this one but LAN as a whole. +-----+ ...
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2answers
149 views

Block all IPs from accessing anything on the server

I want to block all IPs except for my own home IP from doing anything on my server. How can I do this with iptables? For the example lets say my home IP is 1.2.3.4 My server still needs to be able ...
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1answer
73 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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68 views

How to explain strange kernel messages?

I have a server running on Debian Wheezy 3.2.68-1+deb7u1 x86_64. Lately strange records in /var/log/messages appeared. First messages of this log starts just after server reboot. 6.222.18 LEN=44 ...
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29 views

Privoxy - Annoying Error Used IPTables

I'm running privoxy off a machine that also has hostapd installed, I am trying to run all http traffic from hostapd through privoxy i have already tried this: iptables -t nat -A PREROUTING -p tcp ...
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1answer
26 views

Are iptables global or user ip specific?

For example for my web server port I have the following rule: iptables -A INPUT -p tcp --dport 80 -m state --state NEW -m limit --limit 1/m --limit-burst 15 -j ACCEPT #If you spam concurrently for 15 ...
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14 views

iptables presale me to ssh access or calling methods remotely

I have a linux openwrt unit. At its start, I can not make a ssh access if I do iptables -F. If I use iptables -L -n -v, I find several rules that are automatically inserted and it prevents me from ...
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1answer
81 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
77 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 ...
2
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0answers
65 views

ip rule not acting on fwmark

I'm trying to use iptables to load balance web traffic over multiple DSL lines by marking the packets and routing based on the mark. I'm working with CentOS 6.6, Kernel 2.6.32-504.16.2.el6.x86_64, ...
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1answer
80 views

AWS Outbound ACL Rules impact on incoming ssh connections

I am making a bastion ssh server on CentOS 7 in an AWS EC2 instance. When I use the following rules in its ACL, I am able to connect to the server just fine: Inbound Rules Allow traffic on port 22 ...
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1answer
37 views

What ports will an ssh daemon use outbound?

I am making a bastion ssh server. When I use the following rules in its ip tables, I am able to connect to the server just fine: Inbound Rules Allow traffic on port 22 from my client's IP Block all ...
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1answer
42 views

Audit on changes to the running iptables configuration

I'm aware of how to audit for changes to the /etc/sysconfig/iptables file in CentOS/RHEL 6 and earlier, but how do I audit for changes made only to the running configuration?
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2answers
57 views

IPTABLES to allow ssh, ftp, pop, etc from one static IP address with HTTP/SSL open to public

This is my setting in /etc/sysconfig/iptables: #start of my iptables # Generated by iptables-save v1.2.11 on Wed May 27 00:31:22 2015 *mangle :PREROUTING ACCEPT [130933577:29488298585] :INPUT ...
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1answer
39 views

Modification needs to be done in iptables in case of a bridge between two interfaces is implemented

I have a machine with 2 NICs; eth0 and eth1. Each NIC has an assigned IP address and the traffic between them is controlled using the below script. #!/bin/bash SAT_RECV="192.168.200.0/16" NQ=9 ...
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1answer
45 views

Using a VPN for certain applications via a network namespace

I am trying to use a network namespace for VPN-specific traffic, using this guide: https://schnouki.net/posts/2014/12/12/openvpn-for-a-single-application-on-linux/ on Debian. Everything works with ...
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0answers
49 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
58 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 ...
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4answers
224 views

Viewing all iptables rules

I just wanted to ask if there's a way to view iptables rules in a bit more detail I recently added masquerade to a range of ips iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE ...
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1answer
28 views

FTP passive mode, fails

Hi I am trying to setup iptables to allow FTP. When I connect with FTP, i get the following message in my filezilla. Status: Connected Status: Retrieving directory listing... Command: PWD ...
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1answer
60 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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2answers
96 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 ...
0
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1answer
44 views

Unable to setup iptables for ftp passive mode [duplicate]

I tried the following rules to allow FTP: # The following two rules allow the inbound FTP connection iptables -A INPUT -p tcp --sport 21 -m state --state ESTABLISHED -j ACCEPT iptables -A OUTPUT -p ...
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0answers
11 views

Measure data submited to a blocked ip adress in iptables

With: sudo iptables -A INPUT -p all -d $ip -j DROP One can drop all packets submitted to an ip adress (or a range of ip adresses). This method is useful if you want to prevent applications from ...
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1answer
136 views

How to redirect all HTTP request to a local web server

How to redirect all HTTP request to a local web server, supposing we don't have an internet connections Exemple Web server with @IP 192.168.1.1, running apache Client with @IP 192.168.1.X making a ...
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1answer
60 views

Interfaces, IPTables, Connections, Local Connection - Confused :/

I configured my iptables today and ran into some questions i could not resolve yet. So it would be nice, if someone could verify or answer the following to clarify: Each interface can be configured ...
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1answer
43 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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20 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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1answer
39 views

Route a port through a network interface

I'm using OpenVPN on Ubuntu Server to connect to my VPN. That network interface is tun0. All traffic currently goes through the VPN. I'd like to exclude traffic that goes over a specific port, and ...
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0answers
97 views

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 ...
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2answers
90 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
68 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
66 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
27 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 ...
2
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1answer
35 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
75 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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0answers
53 views

“VPN connection failed” when ufw is on even if there are no rules in ufw interface

Ubuntu 14.04 After update related with ufw and switching nvidia drivers back and forth, suddenly, I can't establish VPN connection to internet. I've deleted all rules and reseted profile in ufw ui but ...
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1answer
88 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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0answers
69 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 ...
0
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1answer
35 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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24 views

“iptables -L” isn't showing a rule I just added

I have issue with iptables it's not listing any newly added IPs. I tried both: iptables -A INPUT -s 188.143.232.15 -j DROP and iptables -I INPUT -s 188.143.232.15 -j DROP and service iptables ...
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1answer
47 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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0answers
83 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
52 views

What is blocking: Firewall and tcpwrapper?

Is it possible to find whether firewall(Iptable) or tcpwrapper is blocking a connection without accessing the remote server? (tcpdump?) Thank you,
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228 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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688 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 ...