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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57 views

Forwarding UPnP, DLNA traffic via computer to server

I'm about to tear out what is left of my hair with this. I was able to finally see traffic coming through, but not working in full, when using socat but this setup is not ideal. The idea: I have a ...
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22 views

How can i measure maximum connection, throughput on iptables?

As the title, I have a linux firewall as router. How can I measure maximum connection, throughput on my server? Thanks
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1answer
20 views

DNAT for connecting a subnet via proxy to the internet

DNAT for connecting a subnet via proxy to the internet I want to connect a server in a subnet to the internet via a proxy-server. But I can’t ping a host on the internet (www). Actually the subnet-...
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28 views

MySQL on Ubuntu. 10061 error on 3306

A fresh install of Ubuntu inside of a Virtualbox with LAMP option selected. I am unable to connect to the server via telnet on this port or via ODBC from my host machine. I can ping and SSH both ...
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29 views

iptables, ufw, and psad - scanned UDP port alerts from router and devices on home network

I have a fresh install of Ubuntu 16.04. I configured iptables, ufw (with gufw), and psad using instructions from https://www.thefanclub.co.za/how-to/how-secure-ubuntu-1604-lts-server-part-1-basics and ...
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2answers
54 views

iptables - access to port 3306 timeout

I cannot connect to mysql from a remote server. I have bind-address commented out but when I add rules in iptables to block other connections the requesting server's connection times out. I tried ...
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0answers
61 views

OpenVPN DNS resolution not working

I'm currently trying to get a simple OpenVPN setup working and I'm almost there, except for a DNS (or routing) issue I seem to be having. The client connects to the server just fine, and I can ping ...
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3answers
93 views

IP forwarding on Linux

I have three machines Source Machine Destination Machine - IP 10.20.30.40 Intermediate Machine - Host server1.test.com Source machine has SSH access to Intermediate machine and Intermediate machine ...
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0answers
91 views

iptables: Redirect traffic from destination IP to new IP

I have a PC client. I like to redirect outgoing TCP connections on port 80 with the target IP 1.1.1.1 to the target IP 2.2.2.2. The full connection should be redirected, which means also the answer ...
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1answer
23 views

self-curl blocked by iptables

I can't figure out which rule is missing to make this happen... # iptables -Z ; curl -v -k --connect-timeout 2 http://www.myhost.com/ ; iptables -L -v * Hostname was NOT found in DNS cache * Trying ...
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1answer
39 views

Firewall rules for ssh, ftp and webapps

I'm running a small cluster with Centos 7 and want the following rules for firewall. Have ssh access from anywhere (i'm going to further configure that from /etc/ssh/sshd_config) Have ftp access to ...
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0answers
69 views

Debian iptables load fail

I Have Debian 8 Jessie and I have installed iptables, but it's not correctly. I can add rule just like: iptables -A OUTPUT -s 212.50.128.0/19 -j DROP but it's not working. iptables -L command works ...
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12 views

From what file/script libvirt inject rules in iptables when I start service libvirtd?

Everybody know that libvirt have his own list of rules for iptables, that he automatically inject in our iptables, after we start service libvirtd Problem: After standard installation of KVM and ...
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0answers
41 views

Forward port 80 to 8080 for a specific IP on the network

I have a specific PC on my network running a web service on port 8080. I also have a different machine which acts as a gateway/router, which I configure using iptables rules. What I want to do is ...
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votes
1answer
77 views

Forward SSH to another Host

I have an ubuntu server which is visible from internet, let's call it "jumper". And this server has this name actually because I need that whenever an user SSH this server, it jumps (or forward or ...
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1answer
35 views

How does iptables --hitcount collect its values

Im looking at SSH bruteforce prevention with iptables recent module. I would like to know how does the --hitcount collect the value that it will use? Is it bytes, packets, no. of conntracked items or ...
2
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1answer
38 views

Postfix not accepting external connections

I have set up a postfix server that works just fine when accessed as localhost. However I cannot make it available from the outside. The relevant configs are as follows: /etc/postfix/main.cf ...
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0answers
43 views

Prerouting with iptables, destination port to DHCP ip

I have an iptables rule that translates requests to the same IP from different internal hosts by changing the source port. iptables -t NAT -A POSTROUTING -p TCP -d 173.32.1.2 --dport 873 \ -m state --...
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2answers
53 views

Redirecting log from /var/log/kern.log to a separate log file for iptables log

I am trying to redirect iptables log to another file. Based upon my reading on the net, I did the following: In my iptables rule, I have rules like: iptables -A INPUT -s ... -j LOG --log-prefix "...
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1answer
31 views

Route ipsec to openvpn with iptables

I am not a very experienced user but I do have determination, after a week with no progres it is getting rough. I have two NIC, one facing to the internet and one towards the internal network. Both ...
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0answers
29 views

Can access server via SSH/FTP but other protocols won't work

I followed this guide to setup an "Upside-Down Ternet." Everything was fine up until the part where I configured IPTABLES then I lost SSH connection. Now I expected that because I'm messing with ...
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votes
1answer
56 views

An iptables rule doesn't work

I'm facing the following problem: I want to block the port 8000 being accessed from the network (block all connections except the ones from 127.0.0.1). So to simplify my problem and as a first step, I ...
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1answer
51 views

SAVE IP ROUTE RULES AFTER REBOOT

I have two internet connections from two different ISPs and I need to balance & failover the traffic originating to and from my network between the two ISPs. My settings: FIRST ISP (eth0): 152....
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1answer
71 views

Missing firewallD in CentOS 7 VPS

i fresh installed CentOS 7 in a OVH VPS. but when i ran the command firewall-cmd i got this: -bash: firewall-cmd: command not found so i was looking how resolve that and i saw that basically i ...
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27 views

KVM - libvirt qemu script make duplicates in iptables

OS: CentOS 7 Firewall: iptables libvirt: 1.2.17 Problem: I used guide to make port forwarding from host to gues machines. Link to guide: http://wiki.libvirt.org/page/Networking#...
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2answers
71 views

OpenVPN per user rules while not routing Internet traffic

EDIT: I know that learn-address is what I would need to use to call a script (as specified in the openvpn-netfilter project) to set the firewall rules. I guess my question is more related to the ...
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1answer
33 views

How can I only allow TCP connections for 1 port using iptables on Unbantu? How can I also set a maximum packet on a connection?

I'm running a server for public. I just want to allow TCP connections and I want to limit the packet to prevent ddosing a bit and setting a maximum IP/new connections per seconds with iptables. How ...
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votes
1answer
13 views

iptables port forwarding to specify ip

I use the following command to forward tcp 2222 in a host node to tcp 22 in a vm (192.168.0.100): iptables -t nat -A PREROUTING -i vmbr0 -p tcp -m tcp --dport 2222 -j DNAT --to-destination 192.168.0....
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2answers
48 views

Check if iptables rules are working

I have three virtualboxs. 1) Virtual machine VM-A that works as a router with two interfaces: eth0 - 10.160.10.254 eth1 - 172.10.0.254 2) Virtual machine VM-B that works as an internal network ...
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0answers
26 views

netfilter, block port range [31000-32000] on public interface eth2

I need to block the port range [31000-32000] on my public interface eth2. Services can be accessed using private network interface eth3 I have tried : root@master-sbg-01:~/# iptables -A INPUT -i ...
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0answers
56 views

Drop fragmented packets in nftables

Using iptables is it possible to block fragmented packets with this rule: iptables -A INPUT -f -j DROP But there isn't a equivalent in nftables. There is any way to do it?
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1answer
64 views

Howto configure Ipset to block entire countries IPs

I need to block some countries using ipset and iptables. What I've done so far (create new ipset set 'geoblock'): sudo ipset create geoblock hash:net,port then I created the following script /usr/...
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0answers
27 views

How to isolate two containers connected to the same bridge?

I have several LXD containers which are bound to a single bridge (the default lxdbr0 or another one, it does not matter). The host itself has another two interfaces, one ultimately connecting it to ...
3
votes
2answers
88 views

Ubuntu as NAT Gateway with iptables

I'm trying to configure Ubuntu 14.04 to act as a NAT gateway between a private and public network. Public Interface -> eth0 (178.x.x.x) Private Interface -> eth0:0 (192.168.206.190/17) I've tried ...
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0answers
19 views

Iptables linux routing with 2 chain proxies

Im trying to setup a connection between a PCs in my local network, to foreign resource XYZ in a specific way. My network is currently configured like this: I have a pc behind the proxies -> Then I ...
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0answers
18 views

Iptables multiple port redirects based on destination address

I have iptables setup for selective routing. In the current configuration it checks if the dst address is listed in a specific chain and if it is not it redirects the traffic to my proxy port which is ...
1
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0answers
41 views

Route all traffic from virtual interface to temporary tun0

I'm trying setting up at home an automated torrent client to download some big GIS databases I produce at work and release as .torrent files. My home server is a Raspberry PI with one Ethernet ...
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1answer
14 views

Edited IpTables, now SFTP suddenly stopped working

I removed some things from my IPTables that were no longer needed and now my SFTP simply times out upon attempting to connect with FileZilla: Status: Connecting to ###.93.110.###... Response: ...
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1answer
165 views

OpenVPN Ubuntu Server Routing Problems No Internet

I'm running OpenVPN on Ubuntu 15.04. When I connect to the server, I can connect and authenticate correctly (I use PAM auth because I'm lazy). Once connected I can't ping the server or access the ...
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1answer
190 views

Can't establish SSH connection even on localhost

Having problems getting a simple SSH connection to even localhost on my Ubuntu 15.10. Server was set up many months ago and was able to create access for SSH with keys, but cannot duplicate that ...
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votes
1answer
45 views

How can I block access to the internet for static addresses?

I have a router on CentOS 7 which provides access to internet for several IP addresses, which are reserved at DHCP server. Other hosts are blocked. If someone put static address from the reservation ...
1
vote
1answer
179 views

ICMP ECHO REPLY is not being SNATed correctly

I am trying to provide L3 connectivity between two remote LAN networks (10.0.0.0/24, 10.0.1.0/24) using OpenVPN with the following setup: +----------------+ +---------------------+ +----------------...
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0answers
176 views

CentOS 5.11 apf/iptables; iptables sometimes fails when apf restarts

On one of our old servers, a CentOS 5.11 machine using apf as a front end for iptables, we're having an intermittent problem with iptables failing when apf restarts on occasion. When this happens, the ...
1
vote
1answer
124 views

Allow Docker containers to use IPSEC VPN on host

I have Docker and an IPSEC VPN tunnel on my workstation, but the containers can't access hosts behind the VPN. Is there anything I can do, e.g. with IPTables or routes to allow access? [Note: I'm ...
2
votes
2answers
217 views

iptables / KVM forward port

I have a server with one external IP address (e.g. 1.2.3.4). On that server I use libvirt to run virtual machines. Now I want to access a virtual server on my host via ssh (port 1234) from the outside....
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0answers
51 views

Route all the trafic using iptables nat in linux

I'd like to route all the trafic through iptables NAT in linux, I'd like to route all the traffic through TOR. My script is accepting only TCP and UDP protocols, but I need to route all the protocols ...
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0answers
174 views

IPTables - Redirect ppp0 traffic to external side eth0

I've some servers on 2 differents networks. On the first network ( many servers ), I've only one public IP adress (ex: 193.193.192.192) and a small local network ( 172.16.1.0/24 ) ; On the second ...
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1answer
177 views

Port Forwarding on DROP policy

I'm trying to do a port forwarding on port 80 to a virtualmachine. If I set default policy to ACCEPT on input, output and forward chains the forwarding works. However, if I put the policy on DROP and ...
2
votes
1answer
129 views

Docker - This site can’t be reached

I installed a tomcat image and ran a container: [root@MY_IP ~]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS ...
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0answers
16 views

IPsec and pinging rightsubnets

I have been racking my brain about this. I have openswan running and I have been able to get tunnels up. Unfortunately, when I try to ping computers on my right subnet, I am not able to get any ...