iptables allow creation of rules to define packet filtering behavior.

learn more… | top users | synonyms

1
vote
1answer
293 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 ...
0
votes
1answer
83 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 ...
0
votes
1answer
67 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 ...
1
vote
0answers
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 ...
1
vote
2answers
290 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 ...
1
vote
1answer
68 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 ...
1
vote
1answer
119 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
votes
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 ...
0
votes
1answer
521 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.
0
votes
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: ...
1
vote
0answers
165 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-...
1
vote
2answers
43 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 ...
5
votes
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, ...
3
votes
0answers
202 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
votes
3answers
566 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
votes
2answers
136 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 ...
0
votes
1answer
142 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. ...
1
vote
1answer
134 views

Config iptables ssh over VPN

How can I define a rule that only allows ssh via VPN in iptables? My iptable Rule is following: #!/bin/sh IPT="/sbin/iptables" $IPT --flush $IPT --delete-chain $IPT -P INPUT DROP $IPT -P FORWARD DROP ...
0
votes
1answer
608 views

Switching between Network Interfaces

I am trying to write script to switch between two interfaces on a Linux machine, wlan0 and eth0. My primary reference is: http://askubuntu.com/questions/338100/forwarding-traffic-between-2-interfaces ...
0
votes
1answer
69 views

Nat with saving real client IP

I have this schema: Client -> NAT server -> Game server On NAT server I have the following rules: iptables -A FORWARD -d $MC_IP -p tcp --dport 25550:25580 -j ACCEPT iptables -t nat -A PREROUTING -d $...
1
vote
2answers
2k views

iptables allow only ssh and vpn traffic

I have dedicated server with ubuntu 14.10 installed. The server should connect to an openvpn server and the traffic should only go through the vpn, except for SSH traffic. My idea is to realize it ...
0
votes
0answers
286 views

Get real IP after OpenVPN tunneling

I try to route traffic from one Server to another using OpenVPN. In the end users should only connect to the forwarding machine. It basically works using this iptables rules: iptables -t nat -A ...
2
votes
1answer
4k views

how to block only certain outgoing ip connection with iptables

(Centos 5.5) to block xxx.xxx.xxx.xxx: # iptables -A OUTPUT -j DROP -d xxx.xxx.xxx.xxx then verify by: # iptables -L OUTPUT --line-numbers Chain OUTPUT (policy DROP) num target prot opt ...
1
vote
1answer
524 views

NAT External IP to local server using iptables

I have a adsl connection with static IP (lets say 1.1.1.1). My debian firewall connects Internet with ppp and IP is assigned to firewall directly; ppp0 Link encap:Point-to-Point Protocol inet addr:1....
2
votes
0answers
69 views

Why is traffic matching the public zone instead of the desired zone?

Trying to self-train on firewalld I set up apache and configured the zones as follows: [root@localhost ~]# firewall-cmd --get-active-zones work sources: 192.168.122.1 public interfaces: ens3 [...
1
vote
2answers
569 views

Why do iptables drop / log even if the appropriate packet should be accepted?

I'm setting up a server running Debian Jessie with some applications like iptables firewall, fail2ban, openvpn, apache, ... The iptables firewall is configured in the way, that it logs every packet ...
1
vote
0answers
509 views

iptables: No chain/target/match by that name

I'm trying to configure iptables to get Redsocks working {purpose is to get system wide socks proxy} #!/bin/bash # Create new chain iptables -t nat -N REDSOCKS iptables -t nat -A REDSOCKS -d 0.0.0.0/...
2
votes
1answer
577 views

Iptables can't forward from/to internal LAN with proxmox

I have an host with proxmox with single public ip and some virtual machine installed whit webservers and multiple doimains, the first VM is a proxy with haproxy that forward the request to other VM ...
0
votes
1answer
417 views

IPTables Firewall/Router/Gateway needing to block outbound traffic from users

I have multiple ethX interfaces. eth0 is connected to the internet. eth1 is connected to a trusted network. eth2 is connected to a network I need to impose usage rules. What I'd like to do is ...
2
votes
1answer
3k views

forward packets from one interface to another interface using iptables

I have an embeded system with 2 interfaces e0 and m0, whose ips are 10.0.0.20 and 192.168.0.20, respectively. Incoming packets into e0 have an ip of 10.0.0.10 and should be forwarded to m0 interface ...
1
vote
1answer
710 views

PPTP Through IPTables

If this has already been answered, I apologize, I could not find an answer to this during my searching. I am new at Linux/Unix and I have recently implemented a Raspberry Pi firewall/gateway on my ...
0
votes
0answers
174 views

iptables - How to remove connection tracking

I'm using this command for redirect all web traffic (http) into my local web server iptables -t nat -I PREROUTING -p tcp --dport 80 -j DNAT --to 192.168.11.100 Then i test, access a website and got ...
1
vote
2answers
2k views

iptables - Redirect web traffic to LAN Server

I have a webserver which is running on ip address 192.168.11.100 How can i use iptables to redirect all web traffic (http and https) to my webserver on LAN? After that i want to add except list mac ...
0
votes
1answer
420 views

How can I set up the ULOG target with iptables and MySQL

I'm running CentOS 6.6 32bit as a firewall box using iptables. I want to be able to use the ULOG target to store dropped packets in a MySQL database for statistical analysis. After much Googling I ...
0
votes
1answer
1k views

iptables - Redirect except list MAC Address

I'm using iptables on my router to redirect all web traffic to my page. But i don't know how to except my mac address list. I did command like this: iptables -t nat -A PREROUTING -m mac ! --mac-...
3
votes
0answers
517 views

Routing traffic for specific user to specific interface

I have a Linux box with these interfaces: eth0 Link encap:Ethernet HWaddr 14:da:e9:ef:75:7d inet addr:176.9.85.182 Bcast:176.9.85.191 Mask:255.255.255.224 tun0 Link encap:UNSPEC ...
1
vote
0answers
163 views

Redirect all ARP traffic from eth0 to eth1

I would like to redirect ARP traffic, but I'm struggling with arptables and ebtables. I have 2 interfaces: eth0 10.10.10.25 eth1 10.10.10.20 Both in 10.10.10.0/24 I want to redirect the ARP ...
0
votes
1answer
30 views

how to block my phone from the vps?

My android phone wlan mac is x1:x2:x3:x4:x5:X6 I want to block the phone to logon in the vps. here is the iptable command: iptables -A INPUT -m mac --mac-source x1:x2:x3:x4:x5:X6 -j DROP I found ...
2
votes
0answers
1k views

restrict IP traffic between VLAN sub-interfaces

I have a router/firewall-PC with two VLAN sub-interfaces eth2.100 and eth2.200: I would like to allow communication between networks 192.168.100.0/24 and 192.168.300.0/24(PC3 network). In addition, ...
0
votes
1answer
3k views

Port Forward :80 and :8080 to Two Different Servers

On a CentOS 6 server with an IP address of 172.16.1.10, how can I configure iptables to route traffic destined for 172.16.1.10:80 to 192.168.1.10:80, and traffic destined for 172.16.1.10:8080 to 192....
0
votes
1answer
389 views

Stateful user-space firewall for Linux

Is there any stateful user-space firewall for Linux? I'm looking for a firewall that doesn't rely on anything in Linux kernel (like iptables/netfilter) and works with raw packets.
1
vote
0answers
363 views

Limit transfer speed rate by Iptables Rules

I have D-Link Router DSL-2730U that support busybox OS and iptables version 1.4.0 I managed successfully to block the host for being connect to the internet using the following command block by ip ...
1
vote
1answer
2k views

Java Client Connection Refused by Linux Server

I have a Java server and client, which is a simple server that prints a message when the client communicates with it. It works perfectly fine when the client and server are on the same machine. When I ...
2
votes
0answers
194 views

Dropping packets before mangle POSTROUTING

In iptables on Linux 3.10, why do packets which have been DROPed by the FORWARD chain of the standard table still appear in the POSTROUTING chain of the mangle table? -- I'm trying to use the standard ...
1
vote
0answers
183 views

Shorewall on router keeps blocking apt-get update on virtual guest

I have a dual-IP LXC server with several unprivileged containers configured for three users. Each user has his own bridge: lxcbr0, lxcbr1 and lxcbr2. For efficiency, the host runs apt-cacher-ng. Each ...
1
vote
1answer
148 views

Redirect traffic destined for IP and port

I have a program that wants to connect to 1.2.3.4 on port 5678, but it can't because the port is blocked on our network. However, I do have an SSH tunnel set up that redirects localhost:5678 to 1.2.3....
2
votes
2answers
162 views

What does this iptables rule mean?

Reading this article on how to configure OpenVPN, I see the following paragraph: Raspbian has a firewall to protect your Raspberry Pi from unknown and unexpected Internet sources. We still want ...
1
vote
2answers
2k views

Forwarding a Localhost:Port to an ExternalIP:NewPort

We have got an application running on our linux server. From that application, when we try and access localhost(127.0.0.1):localport, it should be forwarded to an external IP. Users will only try and ...
1
vote
1answer
229 views

iptables, differentiate ports based on hostname

Is there a way, using iptables, to ACCEPT traffic from HOSTNAME1, HOSTNAME2, HOSTNAME3 to port 22 and FORWARD traffic from everyone else to a different port and make the rule persistent? HOSTNAME1/2/...
0
votes
1answer
233 views

How to unmask an IP with iptables?

Is there a way to unmask an IP using iptables? I know to mask all-in-one is following by: iptables -t nat -A -POSTROUTING -j MASQUERADE