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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21 views

Cannot get client to pass DNS queries through openVPN tunnel

I cannot get my openVPN client machine (Windows 10) to pass DNS queries through the VPN tunnel. I am pushing 10.0.0.1 as a DNS server and the VPN connection shows that it is the DNS server for that ...
0
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0answers
13 views

cannot start iptables on opensuse linux

i am trying to run the iptables service on opensuse linux , but unforunately its failing to activate and systemctl status message shows that its failing to find the /etc/iptables.rules file , i also ...
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0answers
18 views

Two ips rotating each time an email is sent - iptables

I have two ips attempting to rotate each time an email is sent from server. The following commands say they are configured: sudo ifup venet0:0 ifup: interface venet0:0 already configured sudo ifup ...
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0answers
21 views

Unable to connect to web server hosted in private subnet of VPC via NAT hosted in public subnet

I have hosted my android/web application on a EC2 instance in the private subnet (10.0.1.0) of my VPC. This instance has apache-tomcat installed on it, but does not have a public IP. I also have a ...
2
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1answer
34 views

I need to REJECT first incoming UDP packet by srcip

Im currently under attack by spoofed udp packets. Every spoofed ip trying to send just 1 udp packet in 30sec. But there is tons of ip. I need to drop first packet. But if same srcip in 30sec sends ...
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0answers
22 views

Router configuration for two WAN with the same ip range

I have the situation depicted in this diagram: I'm trying to route two WANs that are using the same class A IP network, and I cannot figure out which is the proper way of doing it. As a compromise ...
1
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0answers
14 views

Docker's iptables=false option seems to have not the desired behavior

Good morning at all. I am running Ubuntu 14.04 server and Docker 1.8.1 and UFW is my front-end to manage iptables. I need to run an application into a container. I do need the following behavior: ...
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0answers
9 views

Can I use a reverse-proxy on a hosting service to redirect connections to multiple IPs while taking care of maintaining sessions?

I have a situation where I am trying to host my own web server because I need some custom software, including telephony, WebRTC, node.js, etc. However, my net connection in the town and country where ...
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0answers
13 views

Forward port to virtual IP in namespace

So, I followed this guide to make a namespace where I can run my VPN: https://schnouki.net/posts/2014/12/12/openvpn-for-a-single-application-on-linux/ It works fine so far, but I have one problem. I ...
2
votes
1answer
48 views

OpenVPN Access Server: Remote Subnet Cannot Access Client's Resources

I have OpenVPN Access Server running on AWS. Here's the configuration: 172.18.16.0/20 Client (172.18.16.101) ----- OpenVPN Server (172.16.0.0/20) | ...
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2answers
105 views
+50

iptables with transparent proxy, how to pass the user IP

I have a local transparent proxy, but my problem is that packets, when re-routed, have the router IP and not the user. These are the rules that I currently have in place: iptables -t nat -A ...
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2answers
34 views

Trying to access port 3306 (only using it locally)

I am trying to open port 3306 on my archlinux distro. I've tried multiple different iptables settings, but I can't seem to get it to work. (Locally) Here's my current iptables setting: Chain INPUT ...
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votes
1answer
34 views

Port forwaring with iptables generate 404 error on apt-get

I have a server with Proxmox OS installed and some virtual machines inside. Following a guide found on the web i modified my /etc/network/interfaces like shown below to create a virutal interface ...
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votes
1answer
22 views

Config differents external proxy to every VM with iptables

I have a virtualization server with one IP and 5 VM. To get internet access and ssh access in every VM I do this in -------------/etc/network/interfaces------- auto vmbr2 iface vmbr2 inet static ...
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0answers
30 views

Redirect IP to another IP [closed]

My domain redirects to my Teamspeak 3 Server on port 9987, and it works perfectly. But now I will add a second server to block DDoS so I must redirect my domain to server #1 and server #1 must ...
-1
votes
0answers
7 views

Port forwarding within network using iptables [closed]

I'm trying to redirect external traffic internally within my network? This is my set up: External IP- Router - Ubuntu Server (Open to all traffic -192.168.1.2) - Raspberry Pi ...
-1
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0answers
9 views

Can't ping Subnet A from Subnet B with router between them [migrated]

I experimented with subnetting in my home network and Raspberry Pi. The ISP Cable Modem has 4 eth-interfaces and 1 wlan interface which all seem to be switched together. The routers IP is 192.168.0.1 ...
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0answers
36 views

Ping not reaching in OpenVpn clients to subnet and vice versa

I have a vpn server which is connected to vpn client having ip 10.30.0.x now. I want it to able to ping another private client connected to vpn server. Please note that other private client is private ...
0
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1answer
37 views

Can't connect to Nginx from remote browser (weird issue)

I've got a really weird issue with Nginx, I can't access it from my browser. I have installed a CentOS 7 virtual machine on my computer with Nginx, PHP-FPM and MariaDB installed and configured. The ...
0
votes
3answers
170 views

Randomize destination port for *every* packet with iptables

There is a program at server side listens on port 3333, and a dedicated client box which sends and receives packet to the server, I'd like to setup a set of iptables rules, make every packet ...
1
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4answers
71 views
+50

Puppet: converting a custom template into config file

I took over administrative duties for an Linux environment of around 20 boxes. Trying to consolidate configuration management with Puppet. Most is straightforward, however I stumbled on the firewall ...
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0answers
19 views

General matter of stateful iptables

I made a set of stateful iptables rules which only handle accepted traffic (More or less). The workflow can be seen in the image below. My questions are: Is it a good idea to drop INVALID state or ...
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votes
1answer
25 views

iptables allow certain ports and disable the rest

I have the following scenario: I only want to allow access to 22, 80 and 443 ports and everything else permit. My iptables -L looks like this: Chain INPUT (policy ACCEPT) target prot opt source ...
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3answers
38 views

iptables “host/network not found”

If I add this line to my iptables: -A INPUT -s /32 -i tcp -p tcp -m tcp --dport 22 -j DROP I get the error: iptables-restore v1.4.14: host/network' not found` When running: sudo iptables-restore ...
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votes
1answer
16 views

How to ban a ip with fail2ban using fail2ban-client and actionban

I am on fail2ban 0.8.3 and I would like to ban an ip address after reloading fail2ban. I tried: fail2ban-client get myjail actionban ip after that I get an empty line in bash and fail2ban status ...
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0answers
15 views

Is there any reasons not to disallow port scans on a public server?

Port scanners like nmap or angry ip use TCP packets with flags Fin, psh, urg on. Are there any reasons not to block TCP packets with those flags on?
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0answers
46 views

Default gateway is not reachable [migrated]

I have a vmware player on which i have installed CentOS 6.5. And on that CentOS 6.5 i have installed lxc and on that lxc i have installed centos 6.3. I am using NAT and bridger as a Network adaptor ...
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0answers
22 views

openvpn port UDP 53 connectivity issue

I need to run openvpn server on port 53. I have a bind server already running on this port. Here are my iptables rules to let my gateway decide to which service it should redirect traffic: # ...
0
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1answer
19 views

How can I add rule to iptables on ubuntu to enable redis on local ip but not external

I've followed the various scripts to set up 2 linode machines. Both have an external and local Ip. On one I have installed redis, and I want to connect to this machine via the local ip. Which rules ...
0
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0answers
17 views

Iptables config for BubbleUpnpServer

SUDDENLY my bubbleupnpserver is not able to connect on the port 58050 for http and 58051 for https. Yesterday was working, no changes on the server, puff, today no working anymore. Maybe it's ...
5
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2answers
131 views

CentOS 7 iptables not persistent after reboot

I installed a minimal CentOS 7 version on a development server to virtualize some linux guests with kvm/qemu. To use iptables instead of firewalld I install iptables-service and do: systemctl stop ...
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0answers
18 views

iptables hex string match rule migrate to Vyatta (BROCADE)

I have a string match, drop rule working in iptables firewall that I would like to migrate to a Vyatta firewall. Is string matching even possible in Vyatta? If so how can I replicate the following ...
2
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0answers
17 views

Samba server disappears from the browser list after a period of time

I have a Ubuntu server running as a router. On the server I use iptables and DHCP 3.1.3, Samba 3.4.7 and OpenVPN 2.1.0 server. I have problem with Samba server disappears from the VPN client browser ...
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0answers
21 views

iptables configuration for SSDP discovery

I'd like to configure iptables to allow SSDP discovery. SSDP works by sending a multicast UDP packet to 239.255.255.250 on port 1900, to which each UPnP supporting machine in the local network replies ...
0
votes
1answer
22 views

Block redirected port from external access using ufw

I have an application that uses ftp. I redirected the 21 port to 2221. But I see that 2221 is accessible from external even though it is not specified in ufw rules. So I want to block 2221 from ...
0
votes
2answers
27 views

How to list open but not used (by a process/program) port?

I have a VPS with debian wheezy installed on it. A firewall is active on the it with all ports not allowed by default. The firewall can be managed through the web interface of the provider of the VPS ...
0
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0answers
19 views

Expert iptables Nat - Virtual interface ip address issue

I've been looking information related to this problem several days, I had no luck finding a concrete explanation. Explanation about this issue: With this command I redirect one ip to another ip in ...
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votes
1answer
43 views

Port 22 Connection Refused After Ubuntu IPTables Tutorial [closed]

I followed this tutorial from ubuntu on iptables. My commands are as follows: sudo iptables -A INPUT -p tcp --dport ssh -j ACCEPT sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT sudo iptables -A ...
0
votes
0answers
19 views

Loading iptables rules from /etc/init.d/

I decided to load my iptables rules from /etc/init.d/ on my Ubuntu 15 server. Is this good practice? Here is the script I have: #!/bin/sh iptables-restore < /etc/iptables.rules exit 0 By the ...
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votes
2answers
45 views

“Software caused connection abort” after removing rule in iptables

I use Putty to connect to a Linux Red Hat machine on an AWS instance. My local computer is Windows 8. On the iptables I had to make a change and accidentally forgot to put back this default rule: -A ...
-1
votes
1answer
60 views

Route torrent traffic through VPN interface [closed]

I'm trying to set up my own seedbox with rTorrent and I would like to redirect all torrent traffic through my VPN. I know there is a bunch of QA and HOWTOs on this subject. I've read a lot and came ...
0
votes
3answers
53 views

iptables ip address block ignored?

Running top on our server gives us load average: 68.67, 63.48, 60.30 We suspect this is from too many httpd connections. running: netstat -tun 2>/dev/null | awk '{print $5}' | cut -d: -f1 ...
0
votes
1answer
30 views

How to only allow access to a given IP and port on a nat forwarding rule?

I'm using Rancher to manage a set of Docker containers. I'm trying to secure these containers with iptables, and have got as far as completely blocking all access to it and now have been unable to ...
0
votes
0answers
22 views

amazon server using RedHat EL 7 on port 3306 so that i can access mysql database remotely

I want to remotely access mysqld on port 3306 but when hen i telnet from public ip address i get a connection time out error. Whats happening here. But within the server telnet is working just fine ...
0
votes
2answers
43 views

server1 & server2.. because w/same firm.. ssh connection shows private ip.. how to enforce public ip being using during ssh's?

server1 has a private and public ip. server2 has a private and public ip. generally.. if server1 to ssh to server2 .. server2 would recognize server1 by it's public ip. but because both servers are ...
1
vote
1answer
41 views

forwarding from internal to external network does not work

I have a Ubuntu 14.04 LTS server with two NICs. One is connected to the internal network (eth0, 192.168.4.0/24) and the other one is connected to a router with internet access (eth1, network ...
0
votes
1answer
26 views

iptables drop hex-string tcp synack

I'm not sure can drop packet syn ack flood with hex string match, can someone help me and give me clue how to do this? 17:03:10.274551 IP (tos 0x0, ttl 89, id 6656, offset 0, flags [DF], proto TCP ...
0
votes
1answer
45 views

Blocking ddos string with iptables [duplicate]

I want to ask how do block spefic packet payload? 14:46:35.837759 IP 145.92.16.14.27017 > x.27030: UDP, length 25 0x0000: 4500 0035 44a4 0000 ee11 53ae 915c 100e E..5D.....S..\.. ...
0
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0answers
17 views

Cisco Anyconnect + iptables - force all traffic over VPN (and drop all traffic when no VPN connection)

I'm trying to force all traffic over a VPN, and drop every other traffic, just like it was asked and done in this question: iptables - force all traffic over VPN (and drop all traffic when no VPN ...
1
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3answers
66 views

10,000 entries in iptables on CentOS 4GB Ran, dual core 2.3ghz?

I am running a linux box with FreePBX/Astrisk installed. I have blocked China and Hong Kong using lists from ip2location. com/blockvisitorsbycountry.aspx website. My fail2ban was going off like ...