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
-5
votes
1answer
23 views
How to develop a standalone webserver
I try to explain my project. I have a server with 2 interfaces one has to offer a website and absolutely nothing else. The other interface will be used to control and manage this server. To the ...
0
votes
1answer
26 views
NAT via iptables and virtual interface
I'm trying to implement the following scenario:
One VM-host, multiple guest VMs, each one gets its own IP-address (and domain).
Our server has only one physical interface, so the intended use is to ...
3
votes
1answer
32 views
Squid transparent proxy for outgoing traffic only
I have a Rails server that's a bit API heavy and so I want to run a Squid caching transparent proxy, between all port 80 activity, and the real world. However I don't need incoming traffic to go ...
0
votes
1answer
23 views
ssh connection refused with out iptables rulles
I changed the ssh port from 22 to 2021 and it worked correctly till 3hours ago,after that when I can't connect to ssh.
ssh: connect to host 130.185.72.125 port 2021: Connection refused
so I checked ...
0
votes
0answers
26 views
how to log all forward ip address
I am running vpn servers, but some customers using vpn sending spams
so I want to log all ip forward information into a log file
eg: x.x.x.x(public IP)--->forward 10.0.0.x(vpn privated IP)
if ...
1
vote
1answer
24 views
iptables redirect tcp to checkip.dyndns.org from localhost to 127.0.0.1:8118
I've tried several different combinations of rules and nothing seems to be working. I know that you can't use prerouting table for a request coming from the localhost so I used the output table and ...
0
votes
0answers
21 views
What Server Monitoring Software works with csf/lfd/iptables?
Hi I am looking for web based monitor software that monitors Config Server Firewall and works on Debian.
Similar to how http://snorby.org/ works with snort?
Does anyone know if there is such a ...
1
vote
2answers
35 views
restrict Openvpn users to a certain segments
i have three segments behind openvpn server DMZ(192.168.1.x) Dev(192.168.2.x) and PROD(192.168.3.x). Their are two groups of users one group can connect to all segments from openvpn other users i want ...
0
votes
1answer
43 views
How to open port 10011 in centos using iptables
I need to open port 10011 for an application called Teamspeak 3 to work.
I'm using CentOS and i tried the following commands :
sudo iptables -I INPUT -p tcp --dport 10011 -j ACCEPT
i pressed ...
0
votes
0answers
27 views
Real DROP while reconfiguring iptables
I got a quite complicated firewall (8 segments) and sometimes I need to reload rules and add some new vlans. I'd like to quiet the traffic for few seconds while new rules are loaded. I.e. I want all ...
1
vote
2answers
37 views
IPTABLES issue - trying to DROP any connections to 3306 except from 127.0.0.1 and VPN
I have a VPS where I have successfully set up VPN. I connect with OpenVPN client. The VPN server interface is 10.8.0.1 and the client receives 10.8.0.? IP. And I am able to ping 10.8.0.1. I also seem ...
0
votes
1answer
37 views
iptables for openvpn/dd-wrt
I'm hoping some iptables or dd-wrt guru can help me here.
I'm basically trying to configure my network with an additional wireless virtual interface so that I have a separate SSID (wl1.1) that I can ...
-1
votes
2answers
34 views
iptables is deleting all ip's that i have block automatically
After I do add the ip adresses that is attacking me, I do add this iptables -A INPUT -s 109.73.162.160 -j DROP and service iptables save.
The ip that I do add to my blocklist is lost within a few ...
1
vote
0answers
44 views
Windows Firewalls iptables equivalent
I'm looking for an equivalent for iptables in windows, recently my server has been getting hit by a DDoS and I know how to block it using iptables but not in Windows.
I'm looking to do something ...
2
votes
1answer
20 views
iptables after drop ftp goes through
I cannot deny access to FTP for a IP address.
First of all i needed to deny everything so i did like this:
#iptables -F
#iptables -P INPUT DROP
#iptables -P OUTPUT DROP
#iptables -P FORWARD DROP
...
1
vote
1answer
67 views
What is the proper iptables configuration for Apache Solr on CentOS?
I know for a fact that iptables running is causing my instance of Apache Solr to be inaccessible.
How do I know this? Because I ran:
/sbin/service iptables save && /sbin/service iptables stop
...
0
votes
1answer
62 views
How do I allow only US IP addresses using iptables?
I have a site that is only relevant to US visitors and would like to block all non-us visitors from accessing the site. What is the best way to do this with iptables given that I have a CIDR list of ...
1
vote
1answer
31 views
Using knockd with shorewall
I'd like to migrate my old pure iptables firewall configuration to a shorewall setup. I get the basics, but I haven't been able to replicate my existing knockd setup:
I have a 'tmpknock' chain that ...
0
votes
2answers
49 views
Restarting webmin firewall/iptables
I'm trying to figure out how can I restart iptables setup made from webmin.
When created the firewall rules, webmin saved everything into iptables.up.rules.
I used the iptables to DROP as default ...
1
vote
0answers
22 views
netfilter: How to mark packet by reqid?
I have the following problem. I have SAs that use firewall marks. So only packets that have that mark get encoded and decoded.
I managed to set the mark for packets that shall be encoded but I cannot ...
0
votes
3answers
56 views
Is blocking unresolved IP addresses a good idea?
I have a Website where :
We currently have a lot of bots trying to grab our content (it's a
business directory) from China, Ukraine, etc...
5% of IP addresses are "unresolved", according to ...
0
votes
1answer
37 views
Blocking FTP access with iptables
I am trying to set up iptables to log connection attempts to port 21 on a server, then deny the connection. The logging works, but I can't get iptables to actually reject the connection or drop the ...
1
vote
2answers
56 views
iptables blocking traffic
Can someone please explan why IPTABLES is blocking any ports in this list of rules:
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere ...
-1
votes
2answers
118 views
DDOS Attacks Explanation [closed]
I have some questions regarding the ddos attacks and how it really works , i really need some good explanation for it as i can't find any good reference that can help me .
Questions :
what are the ...
0
votes
2answers
41 views
Should I disable iptables when I'm using csf?
Should I disable iptables when I'm using csf ?
any help appreciated.
-1
votes
1answer
81 views
Linux - What's wrong with these Iptables rules?
I just want to prevent nmap and packets that are considered harmful to my VPS (Setup : Debian - Nginx webserver).
After applying these rules and disconnecting from ssh I couldn't reconnect anymore.
...
0
votes
1answer
39 views
service iptables restart does not work
I am trying to add the following line in the /etc/sysconfig/iptables in CentOS so I will be allowed to access mysql.
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 3306 -j ACCEPT
...
1
vote
2answers
71 views
Linux - Counter Measure against Stress Tools
I have a VPS running Ngix and currently hosting a few websites. As you know VPS have low resource and the security measures should be done by client.
I just noticed many stress tools are out there ...
2
votes
1answer
68 views
Slumbering apache server refusing connections, but not via localhost
I'm pushing a moderate amount of traffic (about 20 req/s) to a simple PHP API running on an Apache server. The Apache server slumbers (mod_status barely registers one active request), however, I'm ...
0
votes
1answer
45 views
Why am I still able to get a response on port 80 when I've shut down all ports except 22?
My goal is to shut down absolutely all ports on my Ubuntu server, except port 22 (SSH).
I followed the instructions from this question here on Server Fault, plus instructions here and here.
However, ...
1
vote
0answers
60 views
Disable kernel processing of TCP packets for raw socket
I'm working on a TCP/IP implementation, for an embedded device, that I want to test from a Linux user space process using raw sockets.
raw(7) says that
Raw sockets may tap all IP protocols in ...
0
votes
2answers
36 views
Redirect connection to different port on other IP?
When someone makes a connection to myIP:123, I'd like my server (Ubuntu) to redirect their connection to otherIP:456. Connections to other ports should obviously be treated normally. I'm pretty sure ...
0
votes
1answer
20 views
IP Redirection with iptables and vsphere
I use ESX4.1 (vmware vsphere4) and I have one Public IP (X.X.X.X) in vswif0 and (192.168.1.1) in vswif1 and 2 virtual machines with local IP (192.168.1.2) and (192.168.1.3)
I want to use iptables ...
1
vote
1answer
55 views
Using Ipset and Iptables for MAC address filtering
I use MAC address filtering on my Linux router. Here is what I have done:
iptables -A INPUT -i eth5 -m mac --mac-source 00:07:e9:84:2b:99 -j RETURN #User: Someuser
iptables -A INPUT -i eth5 -j DROP
...
1
vote
2answers
64 views
How can I get port forwarding to work with iptables?
I want to protect my MySQL Server from portscanners/probes. So my idea is to put the external port on let's say 36636, internal port has to stay at the default 3306 for compatibility with local apps.
...
3
votes
1answer
41 views
ipset - recommended method to reload rules after reboot
Am implementing ipset on some Fedora 16 systems.
Since ipset rules run in memory and are lost on reboot planning to use a crontab @reboot script to reload the rules and send an email to administrator ...
7
votes
1answer
378 views
iptables: Port forwarding with masquerading is not working
I'm having some issues with my port forwards. NAT seems to work ok and one out of the port forwards seem to work (udp port 7887 to machine 192.168.1.100). But not the others.
I doubt that it matters, ...
0
votes
1answer
36 views
How to block specific UDP packet outgoing from machine using iptables
I want to block specific UDP packet OUTGOING from my machine using iptables. Packet has a string in "hex in RAW"(?) i want to check packet by it.
Like: If UDP packet hex RAW match "test_text" - block ...
1
vote
1answer
39 views
How to get the average packet rate per ip for a port?
Is it possible with iptables to limit inbound packets by source-ip based on the number of average inbound packets for all source-ips? If so, how?
I'd like to limit new ips to the average inbound ...
0
votes
1answer
56 views
IPTables Rules Slow Connections to Bridge Interface
I have a KVM host which bridges its eth0 as br0. I have one guest which uses the bridge adapter (rather than NAT) with its own public IP.
If I setup basic firewall rules on the host, it suddenly ...
2
votes
2answers
62 views
Redirect traffic between two ports with iptables
My goal is to run a webserver on port 3000 and make it available to my network over port 80. The best answer I found so far is this nice one liner.
iptables -t nat -A PREROUTING -p tcp --dport 80 -j ...
0
votes
0answers
46 views
Redirection from subnet to the Internet with Iptables [closed]
I have this in my home:
laptop -->((192.168.10.0/24))<-- [eth0]desktop PC[wlan0] -->((192.168.1.0/24))<-- router ---> ((Internet))
Meaning: The laptop is connected to the desktop PC via ...
-1
votes
1answer
46 views
Why can't I add two '…-m recent --update --hitcount…' rules to iptables chain?
To stop brute force attacks on my server (OS is CentOS 6) I want to
block for 1 minute everyone who makes more than 4 login attempts during last minute
block for 1 day everyone who makes more than ...
1
vote
2answers
98 views
Increasing `iptables` verbosity and determine logging location on a CentOS based server?
Having an odd problem here with regards to pound reverse proxy no longer directing traffic properly on a CentOS based distro (ClearOS 6.2.x).
I believe that it's an iptables issue or something else ...
1
vote
3answers
52 views
Is it a good practice to allow all ports from netstat result by putting them in iptables
I'm configuring the firewall and several times i discovered it is blocking a service or port that is needed such as dns or https..etc is it safe to do netstat -nat | grep LISTEN then whatever port ...
2
votes
0answers
84 views
How to Enable IPtables TRACE Target on Debian Squeeze (6)
I am trying to use the TRACE target of IPtables but I can't seem to get any trace information logged. I want to use what is described here:
Debugger for Iptables.
From the iptables man for TRACE:
...
0
votes
1answer
42 views
IP Table, what does this construct mean ::INPUT ACCEPT [0:0]
I am looking at an IP Table construct, what does the following mean :
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
thanks
2
votes
2answers
85 views
Forward http traffic to another ip address with iptables
We want to forward all http traffic to another IP address on an Amazon EC2 stock Linux machine (CentOS based). I know how to do this with proxy rules and apache, but I was assuming iptables would be a ...
1
vote
1answer
71 views
Iptables: Forwarding packets doesn't work
I have 3 Linux Systems A, B and C. A is a TCP Client and sends a message to TCP Server on C. A can see only the external IP of B which is at wlan0 interface, 192.168.0.3
------------------ ...
-2
votes
0answers
37 views
My server got its iptable config hacked - How was it done and how to avoid it? [closed]
Possible Duplicate:
My server's been hacked EMERGENCY
I had my server hacked and its iptable was changed. This stopped anyone from accessing any page on the server.
How could this be ...
