Questions tagged as ['iptables']
I have following setup: Proxmox Host dedicated server with one public IP and installed IPTables and bunch of Virtual Machines with docker installed.
I use iptables to port forward port 443 to one of the VM's via DNAT and it works fine from outside of the Host ie Internet. But if i try to access resources within VM running on VM via the public IP it is not accessible.
Use case: i have nginx with SSL ...
Main question is how to connect to a vpn server via a vpn client which is a NAT instance, let me describe about it.
I have a group of service instance(ubuntu 18.04) named A
One instances which i use for NAT instance named B
both group A and instance B are in same vpc, A has no public ip ,B has one pulibc ip, and which i did is use B as a NAT and set SNAT in vpc so group A can access internet ...
So I have 3 OpenVPN Access Servers, and downloaded the config for all 3 of them. Then on my raspberry I ran 3 instances of
openvpn (even with a different subnet configured in the Access Servers) with each of the config files.
My goal is to be able to route incoming traffic to individual devices, e.g.
IP_of_Access_Server_1 leads to
Client_1 in my network,
IP_of_Access_Server_2 leads to
Client_2 etc. That' ...
I have 4 IPs something like that
and two ports
my Linux server should connect those IPs with ports. Now I want to make this process automatic. To be more precise, the server tried to connect
10.10.10.11:1000 but it failed now it should try to connect
10.10.10.11:1001 automatically and so on.
The problem is that I do not know how to do it. ...
I'm trying to achieve something easy but apparently I'm missing something.
In my box I have a VPN client running which created a
tun0 interface. The box has external traffic coming from the
I would like to forward the traffic from
tun0. I run the following commands:
iptables -A FORWARD -i eth0 -o tun0 -s 192.168.100.0/28 -j ACCEPT iptables -A FORWARD -i tun0 -o eth0 -m state --state ESTAB ...
I have a number of public ips behind a debian router connected to vms. I want a specific ip not to be able to use port 25 outgoing.
I have tried /sbin/iptables -A OUTPUT -o ens19 -p tcp --destination-port 25 -s xxx.xxx.xxx.xxx -j DROP along with several other combinations of command but I cannot get it to work. It will block outgoing ports on the router fine but not for systems behind it.
I have iptables starting from
root@Ubuntu-18-VM:~# iptables -S | grep -oP '(?<!^:)cali-[^ ]+' cali-FORWARD cali-INPUT cali-OUTPUT cali-cidr-block cali-from-hep-forward cali-from-host-endpoint cali-from-wl-dispatch cali-from-wl-dispatch-5 cali-fw-cali2847b154969 cali-fw-cali4bb24809f90 cali-fw-cali531f8f2e712 cali-fw-cali5a82b3ff301 cali-pri-_CV ...
I'm trying to debug some networking issues and I'd like to add the "router alert" flag to some SYN packets that are being sent from my server. Is there a way to do that using iptables?
I'm looking at the mangle table but I couldn't find anything on adding arbitrary tcp header options to the packets. I imagine it would be something like
iptables -t mangle -I OUTPUT -p tcp --dport 22 --tcp-flags SYN SY ...
I observed that netfilter changes the source port when a connection is established in the conntrack module. I need to prevent this behavior.
Here is what I have done to reproduce my problem:
- I create a netfilter rule that will perform DNAT from port 2002 to 2003
sudo iptables -w -t nat -A OUTPUT -s 192.168.30.3 -d 192.168.30.1 -p udp --sport 2001 --dport 2002 -j DNAT --to-destination :2003
- I t ...
I have this rule in my iptables to block domains ending with
sudo iptables -A OUTPUT -j DROP -m string --string ".watch" --algo kmp
But the problem is that the
. cannot be matched. So the line above does not match anything. But if I remove the dot from
watch it works okay.
How can I block the dots "." in iptables rules?
Output iptables drooping 443 even when rule allows it
This are my current rules
INPUT DROP [2:406] :FORWARD DROP [0:0] :OUTPUT DROP [0:0] :DOCKER - [0:0] :DOCKER-ISOLATION-STAGE-1 - [0:0] :DOCKER-ISOLATION-STAGE-2 - [0:0] :DOCKER-USER - [0:0] :LOGGING - [0:0] -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -s 192.168.1.1/32 -p udp -m udp --sport 53 -m co ...
I'm having trouble seting-up iptables on Ubuntu 20.04.
Does anyone know why this doesn't work?
# iptables -A INPUT -m set -–match-set cf src -p tcp -m multiport –dports http,https -j ACCEPT iptables v1.8.4 (legacy): unknown option "set" Try `iptables -h' or 'iptables --help' for more information.
cf has the cloudflare ip's:
for x in $(curl https://www.cloudflare.com/ips-v4); do ipset add c ...
I live in a country where there is no DDOS protection for game servers ( UDP Protocol ).
Since latency is important for users, I can't host it in other country or region.
So I have only one option left and that is using fail-over servers.
I have a main dedicated server where game server is running.
I have 64 dummy VPS where I have installed Nginx proxy.
So the main server's IP ...
Could you help me?
sudo echo "1" > /proc/sys/net/ipv4/ip_forward sudo iptables -t nat -A PREROUTING -p tcp --dport 443 -j DNAT --to-destination 184.108.40.206 sudo iptables -t nat -A PREROUTING -p tcp --dport 80 -j DNAT --to-destination 220.127.116.11 sudo iptables -t nat -A POSTROUTING -j MASQUERADE
I am using these iptables rules to create loadbalancing servers. I am just distributing .mp4 and .mp3 contents, b ...
I'm working on a site-to-site vpn, where one end us a UDM and the other is Strongswan. The goal is to provide bi-directional routing into a cloud environment. I'm completely baffled why this isn't working.
The good news is Strongswan connects and will pass traffic. But I have some routing issues on the Strongswan side. My Strongswan host has two interfaces, eth0 which has the public internet IP o ...
I'm trying to route traffic between two openvpn servers; I would like to have the following connection:
Client --> OpenVpnServer1 --> OpenVpnServer2 --> Internet
I have both servers running and working separately, but I have tried to configure OpenVpnServer1 to forward all it's clients traffic to OpenVpnServer2 using iptables but failed.
OpenVpnServer1 Interfaces and configs:
eth0 -- public inter ...
I want to redirect all the traffic from my computer from port 443 to port 8443. All the traffic is on the same machine. A proxy server is listening to port 8443 and i tried to add the following Rule:
sudo iptables -t nat -A PREROUTING -i wlp3s0 -p tcp --dport 443 -j REDIRECT --to-port 8443
But my proxy didn't get any package. wlp3s0 is my wifi adapter according to ifconfig. What did i wrong?
I have a kubernetes set up with a pod containing the following containers:
- Squid container
- transocks (like redsocks); a transparent SOCKS proxy
I am running this in k3s locally on a linux PC and want to transparently proxy all outgoing traffic from the PC through this transparent proxy. So outgoing host traffic forced to the transocks port on the kubernetes pod. Right now it is not working, the co ...
Given: a CentOS 8-powered computer with three network adapters.
eth0, eth2: external, connected to two different ISPs
eth1: faces home network (intranet)
The task: allow accessing certain internal services from either ISP. There are several services, I only mention SSH below.
In the configs below:
IP1: external IP at first ISP (ISP1), assigned to eth0
Gateway1: IP of gateway provided by ISP1
Trying to understand the
TEE module of iptables.
Intend is trying to clone and send the same packet to 2 IPs
Tried the following
iptables -A INPUT -P tcp --dport 2003 -j TEE --gateway IP1 iptables -A INPUT -P tcp --dport 2003 -j TEE --gateway IP2
tee the traffic to both gateways or only the 1st rule?
running the command
iptables -L -v shows the rules and packets getting counted against ...
Guys how can I convert the following commands to firewalld accepted format ?
iptables -A FORWARD -s 18.104.22.168/23 -p udp --dport 25 -j DROP iptables -A FORWARD -s 22.214.171.124/23 -p tcp --dport 25 -j DROP
I'm trying to limit download and upload speed of each wireguard peer to 512kbit.
The problem is that my following commands, only limits download bandwidth of peer and doesn't limit upload bandwidth. Any help would be appreciated.
tc rules for example peer with ip 10.7.0.2 and iptables mark 12:
tc qdisc add dev eth0 root handle 1: htb tc qdisc add dev wg0 root handle 1: htb tc class add dev eth0 pare ...
Was trying to clear the firewall settings in my RedHat Linux server.
iptables -F, I am not able to reach the server.
# iptables -L Chain INPUT (policy DROP) target prot opt source destination ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED ACCEPT icmp -- anywhere anywhere ACCEPT all -- anywhere an ...
I'm slowly trying to learn iptables and would like to redirect all DNS (port 53) requests not coming from/to a list of IPs (from 192.168.2.1, 192.168.2.29 or to 126.96.36.199). I figured I can use chains. It does not work though. Could you please give me a hint:
iptables -N dnsrewrite iptables -A dnsrewrite -s 192.168.2.1 -j RETURN iptables -A dnsrewrite -s 192.168.2.29 -j RETURN iptables -A dnsrewrite - ...
I want to analyze my Debian 9 server's network workload to detect some possible network overloads.
The main metrics I need to analyze are:
- CPS (connections per second)
Is there a way to obtain these metrics from within Linux?
I thought that CPS metric could be somehow obtained through conntrack
NEW connections events but not sure that this would be the most proper way..
Sorry if obviou ...
I'm setting up TPROXY on my VyOS router to forward certain traffic to a local transparent proxy. It works pretty well, until I discovered that all of my DNAT port forwarding rules are no longer working (connection timeout when connecting from external network).
10.0.0.1/24(Proxy is running on
1234port and adding SO_MARK with
- Internal Host:
80should be expo ...
I've server and virtual machine on it. I'm hosting OpenVPN on this server. The virtual machine has two interfaces: ens18 - for public IP, ens19 - for an internal network. I'm trying to ping 10.2.0.3 (virtual machine ip on ens19) via VPN, but it's not responding. When I run
tcpdump -i ens19 icmp on the virtual machine, its returning this:
tcpdump: verbose output suppressed, use -v or -vv for full protocol ...
I want to internally publish an SMTP server (IP 10.0.0.10) that is behind a VPN tunnel on my internal server (192.168.0.12) using
strongswan is running within a docker container.
For this I want my internal server
192.168.0.12 to listen to its 25 port and to forward the traffic to the tunneled server on the same port
So far I tried using iptables, but without success.
I'm trying to build a chain WireGuard Tunnel. Right now testing, but I'm stuck.
I have two WireGuard servers, 1st one is in India 2nd one is in Singapore. Here is what I'm trying.
Client < 10.26.26.0/24 > India < 10.26.27.0/24 > Singapore
IN Tunnel Peer: 10.26.26.20/32 SG Tunnel Peer: 10.26.27.20/32
I was able to deploy the WireGuard on both servers. And now I'm trying to establish a c ...
I have successfully setup a vpn tunnel with
strongswan within a docker container and want to use that tunneled connection to forward specific ports like SMTP to a host on the other side of the tunnel, in my case
The goal would be to be able to use SMTP in my app directly by connecting to
strongswan-container service in the middle like this