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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8 views

Centos internet sharing with dual WAN and subnet routing

Situation is like this: eth0 has internet access with VPN for 2 subnets 192.168.2.x nad 192.168.30.x eth1 has internet access eth2 is the one to be the connection to allow internet connection ...
0
votes
0answers
9 views

Return OpenVPN Internet clients' traffic to non-default gateway

At home I have an OpenVPN server which is at the same time an OpenVPN client. The purpose is to share one foreign IP address between several devices. In the local network everything works fine since ...
3
votes
1answer
22 views

Is the use of the RELATED state in iptables used properly?

I have been seeing many people using the ESTABLISHED and RELATED flags together to ACCEPT traffic through once a connection was previously accepted (see Allowing Established Sessions). Say I setup my ...
0
votes
0answers
18 views

iptables multiple interfaces same subnet to multiple vlan interfaces

In our lab network we are running multiple virtual routers and want to replace them with iptables. I am not sure if this setup will be possible nor not sure where to start. The new setup will be a ...
-2
votes
0answers
22 views

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

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 ...
-1
votes
1answer
25 views

what is wrong with this rsyslog configuration?

I am trying to get rsyslog to log to the following custom log file /var/log/iptables.conf instead of syslog. Iptables has got logging enabled, here is an example log line outputted from iptables ...
-1
votes
0answers
17 views

Postfix to Use Ipv6 on Rotation Basis [on hold]

I want to setup my vps to use ipv6 on rotation basis and make ipv4 as incoming for postfix. i have 16-ipv6 address and 1-ipv4 address Need help in configuring the same in my vps. It has centos 64 bit ...
3
votes
3answers
154 views

Iptables rules with ! character

I have entered iptables rules to log a specific connection on our server, but it doesn't seem to be working as I want it to. Here are the rules: 1 LOG tcp -- !10.51.0.0/16 ...
0
votes
0answers
11 views

Syslogd acctack

My hosting company told me, my VPS server (CentOS release 6.6) have abnormal activities issue (hacking other server) and blocked my outgoing traffic, they just give me limit info: The hacking ...
0
votes
0answers
18 views

Linux - iptables - get youtube streaming bytes usage [on hold]

How do i get bytes usage using iptables for particular IP for all data usage including youtube streaming videos Currently i am using following IP tables rule to get data usage by particular IP ...
1
vote
1answer
20 views

How do I get firewalld to restrict access to all except specified IP addresses?

I would appreciate some assistance with configuring firewalld please. Here's a bit of background. All I want to do is prevent all access- except whitelisted IP addresses to a web application running ...
-1
votes
0answers
15 views

How to force users binding to specific IP, using IPtables?

I want to give some web users the possibility to have a dedicated IP, both for receiving and for sending. So it means a web script for WEB user XX, received by Apache on IP x.x.x.x, when opening ...
2
votes
0answers
38 views

How do iptables work with NFQ in terms of traffic shaping in snort?

I'm trying to understand how iptables and NFQ work together with snort. The reason that I ask this is because from what I understand snort can be set to IPS via NFQ but if you have iptables there ...
0
votes
1answer
46 views

ipTables IP Range will not be blocked

I have setup fail2ban with this Tutorial http://wireflare.com/permanently-ban-repeat-offenders-with-fail2ban/ and it seems working. But the attackers are changing their IPs and thats why I decided to ...
0
votes
1answer
5 views

Secure elasticsearch but allow remote CRUD

I'm going to run a bit of software on server A to add and remove entries from elasticsearch on server B. How can I allow these remote create and delete operations, but still keep ES secure? Is ...
0
votes
1answer
34 views

Cannot acces Port 8443 of my Ubuntu server

I try to connect to my Ubuntu server over port 8443 using nmap. PORT STATE SERVICE VERSION 8443/tcp closed https-alt As you can see to the outer world the port 8443 appears to be closed. ...
0
votes
0answers
15 views

iptables, after specifying an interface to drop traffic it drops all traffic of all interfaces

We have currently the situation that one interface (eth0) is linked to the internet. and we 2 other devices (eth1/eth2) for management purposes. Now the idea is to block off eth0 completely from the ...
0
votes
1answer
39 views

Setting up iptables filter to allow Git

Sorry I am new at this server stuff, so bare with me and if I'm missing any info let me know! I'm trying to setup my Ubuntu 14.04.2 LTS server to have a solid iptables firewall. Right now I think it ...
-1
votes
0answers
7 views

guest wifi with Hostapd [closed]

Hi i'm using Hostapd with the following config. wlan0 bridge to br0 and getting a dhcp from my router (range 192.168.2.1-100) wlan0_0 also bridge to br0 and getting dhcp from dnsmasq (range ...
-1
votes
2answers
76 views

iptables rule to send email

I have to send emails (and only send, not receive) from a linux server (SUSE Linux Enterprise Server 11) and I think I should add kind of the following rule to the iptables: iptables -A OUTPUT -p ...
0
votes
0answers
19 views

Increase Max prefix length for --log-prefix in iptables

I am using centos and iptables complains about the Max prefix length which is 29 for --log-prefix option. How can I increase this limit?
0
votes
0answers
12 views

OpenVZ container(s) and NAT

I have been trying to days to solve my NAT issue with OpenVZ. I have used their guide on their website/wiki, however I just seem to be unable to get it to work. My Linux box is running on CentOS 6 ...
1
vote
2answers
43 views

How do I drop requests from dig?

Basically I'm getting tons of request to my named/bind service, basically those requests are being rejected by named, Those are the messages i get, from tons of ips., How extacly can I drop those ...
-1
votes
1answer
49 views

trouble opening port 8080 on rackspace dedicated redhat linux [on hold]

I have a server running apache on port 80, and I'm trying to setup nginx running on 8080 to setup/test nginx setup before switching out apache for nginx. I've never had issues opening a port before, ...
0
votes
0answers
32 views

Source IP rate limiting in iptables: hashlimit vs recent

I want to perform rate limiting per source IP in iptables. For example, limit the rate at which a host can establish new SSH connections to 5 per minute. To my knowledge there are two ways of doing ...
0
votes
1answer
30 views

Why is port 443 (but not port 80) being exposed to nmap when iptables is configured to drop the traffic?

A Debian box is running web services on ports 80 and 443 and iptables is configured to allow web traffic only from white listed ip addresses. A second Debian box (that is not white listed) is using ...
1
vote
1answer
86 views

Docker - Exposed ports accessible from outside - iptables rules ignored

I have a docker container running like: docker run --name some_container_1 -p 8080:80 -d some_image Which works fine. The container exposes it's port 80 to 8080 and is accessible from localhost. ...
-1
votes
1answer
26 views

How to implement iptables using Puppet

i would like to implement these rules below in puppet from puppet master to clients Could anyone help me to get the script for this iptables rules, and in which file we want to have this below ...
0
votes
2answers
45 views

Redirecting RDP (port 3389) with iptables

I have a Debian server with an IP 10.10.10.5 and a Windows computer with an IP 10.10.10.7. My plan is to make the Debian server forward all RDP traffic to the Windows computer with these iptables ...
1
vote
1answer
33 views

iptables KVM prerouting SMTP

I have a host machine that has to manage traffic on port 25 and route to port 25 on the KVM machine for postfix deamon like this scheme: WAN --> (25) HOST_MACHINE --> (25) ...
0
votes
2answers
47 views

Ubuntu Iptables Dual Wan - Forward wan 1 & 2 to an internal server

I'm having problems configuring iptables rules on a double wan setup. The OS is Ubuntu 12.04 LTS. I have 2 Wan connections, both with static IP. Wan-1 is on eth2, Wan-2 is on eth4. I want both of ...
1
vote
0answers
41 views

Virtual IP Pool for NAT with StrongSwan VPN

I'm trying to wrap my head around a site-to-site VPN configuration using StrongSwan that will allow remote sites to connect to our AWS VPC. The catch is, the remote gateways will potentially be using ...
0
votes
0answers
35 views

iptables command to get bytes used by specific ip on port 443

I have hosted a WiFi network and i need to monitor data usage by every IP address on port 443(https) Here is the iptables rule used to share INTERNET from eth0 to wlan0 sudo iptables -t nat -A ...
0
votes
0answers
10 views

Guest as Virtual machine connection to Host [migrated]

I have guest run on my machine on qemu with configuration: /usr/local/kvm/bin/qemu-system-x86_64 -enable-kvm -cpu host -smp 8 -hda ${TEST_VIRT_ENV_IMAGE} -m 4096 -netdev user,id=user.0 -device ...
2
votes
0answers
43 views

When is route lookup performed when a packet flows through iptables?

Iptables is often illustrated using diagram I fail to understand when route lookup (routing tables) is performed: inside the "Routing Decision" grey boxes? If so, does it mean a packet is routed ...
1
vote
1answer
22 views

iptables rules for StrongVPN-like VPN endpoint

Goal: To replicate the functionality I have with StrongVPN on my own Debian VPS. With StrongVPN, seemingly, all ports on the public IP provided are forwarded to the client, meaning, e.g, ssh :22 from ...
1
vote
2answers
44 views

How to use a server as a “tunnel” in between the clients and the router, in a small network?

Consider a small network with 1 router (192.168.1.1) and clients (192.168.1.x). The router (OpenWRT) provides Ethernet LAN and WiFi for the clients, to connect to the Internet. Now, I want to use a ...
0
votes
1answer
24 views

CentoOS - iptables issue when trying to enable specific IP

I've got the following iptables: num target prot opt source destination 1 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 2 ACCEPT all -- ...
0
votes
0answers
25 views

HowTo: OpenWRT routing/tunneling all traffic through an inline Snort sensor

I want all traffic that hits the OpenWRT router redirecting/ tunnelin through a dedicated Snort/Suricata machine, before it leaves the local network. The Snort/Suricata machine should act as an inline ...
-1
votes
2answers
39 views

IPTables not blocking IPStresser [closed]

I have been trying four days to block DDoS attacks with no success. I want to block anything that isn't whitelisted. This is my idea on OS Centos 7: //Delete All Existing Rules iptables --flush ...
0
votes
0answers
23 views

Iptables forward traffic from A to B where A is not gateway for B

I want to forward ssh traffic from A port 2222 to B port 22. I do have ipv4 forwarding set to 1 on both interfaces. Still, this does not work. What is wrong? Machine A: eth0 192.168.0.150 eth1 ...
0
votes
0answers
25 views

Strange issue with nginx proxy upstream and ssh port forwarding

We were using nginx legacy till now, but we upgraded our system to 1.6.2 recently. We have a port forwarding of ssh as well as load balanced nginx server for two separate internal servers. The ...
1
vote
1answer
30 views

iptables can't NAT multiple IP addresses

I have a server with two network adaptors: eth0 and eth1. This server is running two distinct https webservers: One is listening on eth0 (172.29.49.112:8443) The other is listening on eth1 ...
-1
votes
1answer
22 views

how to configure fail login delay using iptables

Like in Subject, I need to set particular delay i.e. when wrong password is provided. I can't use PAM. Thanks for any help.
0
votes
0answers
19 views

How do I ban IP's that request files that do not exist using fail2ban? [duplicate]

I have recently started using Fail2Ban and need to configure a specific 'Jail'. My apache error logs are filled with requests for files within my /var/www folder. The folder doesn't contain any ...
0
votes
0answers
22 views

Ebtables to setup forwarding and nat

I would like to use ebtables to perform the following 2 things without using bridge-utils SCENARIO I: I would like to forward all the packets received from eth0 interface onto the eth1 interface. ...
0
votes
4answers
236 views

telnet cannot connect to port without firewall

If I try to connect to MySQL with telnet myhost.com 3306 I get a network not reachable error, even when I flush all iptables rules. I can reach other ports like ssh (with the same iptables rules ...
0
votes
1answer
73 views

Setting up Squid Transparent Proxy on a machine separate from the router

As explained in the title, I'm trying to set up a Squid Transparent Proxy on a machine separate from the router, and also separate from the private network I want to filter through the proxy. The ...
0
votes
0answers
15 views

Traffic accounting with iptables with multiple chains

I have a linux firewall setup with 3 zones: - green for LAN (192.168.0.0/24) - blue for WLAN (192.168.1.0/24) - orange for DMZ (192.168.2.0/24) All zones have systems running and I want to know what ...
1
vote
0answers
51 views

openvpn TLS handshake fails on client because firewall drops packets (but why?)

I seem to have problem with my openvpn server - client connection. now, the important information is in the log (verb3) of my client: Mon Mar 30 17:09:59 2015 OpenVPN 2.2.2 ...