Questions tagged [nat]

Network address translation (NAT) is a network technique that allows that a public IP can be shared by many private hosts (machines).

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share internet , connecting to vpn

I installed a vpn import the vpn settings (protonvpn) through the ubuntu vpn panel I configured username and password. vpn works normally on ubuntu machine. which works as a gateway to another machine ...
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NAT from internet/firewall thru a Ubuntu computer, to another network and device. (routing)

(Ubuntu) computer has two network interfaces: (and is not sunning iptables) wlx1cbfce8bd2bd: inet 10.1.1.129 netmask 255.255.255.0 on this network, there is a device:  10.1.1.10 - with a UDP port ...
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Ubuntu as Gateway and Firewall doesn't NAT the router

I want to configure a network like this: Modem (local ip: 192.168.178.1) -> PC Ubuntu Server 20.04 with 2 LAN as Firewall and Gateway -> Router (local ip: 192.168.178.6) -> Switch->... ...
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Home Router NAT Network configuration Ubuntu 20.04

I have Ubuntu 20.04 desktop and home router and I trying to open ports to have an acces from internet. Here is interface info 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN ...
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Why can't I access the internet when using static ip in a vm? (Netplan)

I'm trying to configure a network like this using VMs: For this I have to configure a NatNetwork in virtualbox. Here is the configuration: As you can see DHCP support is unmarked. Now. I try to ...
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Bifurcation of packets depending on LAN and WAN traffic and forwarding them to different gateways

The current scenario of my interfaces with their IPs and Gateways are as follows. PC1 -> IF11 192.168.1.100 GW 192.168.1.220 PC2 -> IF21 192.168.1.210 GW 192.168.1.1 IF22 ...
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NAT Ubuntu 20.04.2 LTS

I need help configuring the network on my Zabbix Server, if anyone can direct me to what I should do, I appreciate it! I have 3 NICs on my Ubuntu 20.04.2 LTS Server, configured in NetPlan: network: ...
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configuring two network interfaces on ubuntu 20.04

First a bit of background on the problem, I'm trying to create a dynamic malware analysis lab so I'm running inetsim on this ubuntu vm and I have a couple of other vm's on the internal network ...
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Ubuntu 20.04 on VMWare 16.1.2 - no internet connection with NAT

I have couple Ubuntu VMs - 20.04.1 and 20.04.2. Both are set for NAT connection. Both have identical setting except 20.04.1 has Docker installed and 20.04.2 has Minikube. Both at one point had ...
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Webmail behind firewall

I hope someone can point me to a guide or help set up a mail server behind a pfSense firewall that would be separated from the web page. I am a relative newbie on Linux, so the more detailed, the ...
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Ubuntu 20.04 gateway, iptables NAT and port forwarding

i am in a maze, i try in vain to setup the rules to be able to acces from internet my internal web server (192.168.12.10). at home, i have an Ubuntu 20.04 gateway (192.168.12.1) with two interfaces : ...
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Bad argument in iptables NAT command

I am trying to do a DNAT rule in iptables if the packet with source address 192.168.86.212 and destination address 192.168.86.212 then change the destination address to 172.217.5.100. sudo iptables -t ...
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Routing ubuntu server 20.10

I can't configure routing on my server because of: https://i.stack.imgur.com/Q64Gr.png Have you any idea?
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Ssh and Nat forwarding

New here and also in dealing with networks. First I'd like to apologise if my post is looking messy, cos I typed and copied everything and in the texting box is looking nice but the preview is very ...
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Can't connect to Vsftpd Server - Passive reply with unroutable address

I have installed Vsftpd Server listening on port 21 in ubuntu server. I've forwarded a port in my router to forward external port 8500 to internal port 21 where my vsftpd server is listening on. ...
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Network routing and port forwarding problem

I have 2 networks (graph in link below) A: 10.0.0.0/24 B: 192.168.1.0/24 In network A, all devices are connected via a switch. Some devices provide certain services such as ssh or access to a database ...
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SSL on Ubuntu 20.04 with shared IP

I have an Ubuntu 20.04 machine and I'm trying to install SSL via Certbot. The machine has a shared public NAT IPv4 and only a certain range of ports are available for use. I used DNS-01 for ...
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Link-local 169.254.x.x address assigned at boot despite static IP on 20.04 LTS

I have been struggling to setup my Ubuntu machine as a simple 2-NICs router with NAT, trying to stick to most recent recommended methods, namely netplan for the NICs and ufw for firewall and for ...
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DDNS / NAT / DNS / internal name server

I have a registered domain and DNS running on a ISP. For this domain, I have NOIP pointing to my home network behind NAT, and it works well, so, from outside, I can type my servername and have it. I ...
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IPSEC site-to-site overlaping networks

we have two sides connected over ipsec using strongswan. both machines ubuntu 16.04 servers. the issue is both end subnets are overlapping. we have tried all possible iptables scenarios to map ...
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Ubuntu Server - "Virtual" Network Interface with Internet Access

I have an Ubuntu 18.04 server with one public network interface (eth0). I'm trying to create additional "virtual" network interfaces that will also be able to access the internet with NAT rules set up....
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port unreachable on pings from guest VM to internet. (KVM Virt-Manager default NAT network)

Using virt-manager, KVM on Ubuntu, I created a VM with default network configuration (NAT) as described here: https://wiki.libvirt.org/page/VirtualNetworking under NAT mode. which should have ...
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create NAT Network in Virtualbox - hardware virtualization enabled - cannot disable

Good morning, I am encountering some issues when trying to create a NAT Network in virtualbox. This is the error message that I get (and keep on getting) : the hardware virtualization is enabled ...
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OpenVPN tun0 routing on server

I have an OpenVPN tun0 10.8.0.0 255.255.255.0 There is an interface on the server eth1 for 192.168.0.0 255.255.255.0 I would like to route the OpenVPN connections to access the 192.168.0.0 network. ...
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Enable both NAT and Host Only on Ubuntu 18.04

I am using Ubuntu 18 minimal image to create an Ubuntu server with VirtualBox. I created a host only network and added adapter to vm along with NAT adapter (already configured). The original ...
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Permanent redirect on Ubuntu for Mosquitto bidirectional MQTT traffic

I need to permanently redirect all traffic in the short term from an old mosquitto server to a new one until the firmware updates have been completed on the edge devices. I tried using iptables as ...
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Ubuntu installed on Vmware but cannot get access to internet

I installed Ubuntu 14.04.1 on Vmware, the host machine is Fedora 30. However, I cannot get access to internet from Ubuntu. I am not clear how to identify the cause and fix it? Thank you for the help.
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How to use IPtables for load balancing in gateway

I have 3 NICs. NIC1 and NIC2 are used for internet connections an LAN is used for intranet connection. I want to balance the load to ISPs using ip tables. As I am a noob, my crude attempt is given ...
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LINUX 16.04 port blocking and ip blocking

My condition is there is a local network with 3 computers Comp A (10.1.1.7 and 172.16.1.12 and 192.168.0.4)(actually Comp A has 3 network interfaces) Comp B (10.1.1.13) Comp C (172.16.1.5) Comp A ...
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How to forward port with UPnP?

I want to forward port at work, but when i run upnpc -a 192.168.8.80 45444 45444 TCP I get an error List of UPNP devices found on the network : desc: http://192.168.15.34:5000/ssdp/desc-DSM-eth0....
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How can I get back my router configuration in Ubuntu 16.04 server after shutdown?

I shutdown my Ubuntu Server 16.04 after configuring it to the router using. sudo shutdown now The next day when I reboot, PC cannot update. My NAT configurations are gone. When I type sudo apt ...
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Internet access not functioning in Ubuntu 18.04 VM

I'm using Ubuntu 18.04.1 LTS in a VirtualBox VM instance. I am building an internal network in accordance with an article on setting up a non-internet accessible, isolated virtual network environment ...
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How do I remotely control an Ubuntu GUI session from behind a NAT?

Of course I can use Remmina and the like, as in this answer. But both the source and target Ubuntu laptops are behind their own routers (NAT). I am not able to configure port forwarding. Some sort ...
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iptables setup for routing

I want to setup my ubuntu computer to route packets. Therefore I've read several tutorials which always had many rules to add to iptables. I finally found out, that the only rule needed (given that ...
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Routing between 2 wired interfaces without using NAT features

I have two internal networks (I do not want/have Internet access) where I connect my Ubuntu 14.04 (with eth0 and eth1 network interfaces). From eth0 (network 192.168.0.0) I connect another PC1 ...
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How to configure port for external access?

I need to access software from another machine in PORT 3000, but I can not do it for the IP of the machine, only by localhost. erick@erickmordecai:~$ ifconfig enp3s0: flags=4163<UP,BROADCAST,...
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Virtual machine without Internet

I have a VirtualBox machine with Kubuntu and I lost Internet suddenly two days ago. I didn't do anything but uninstalling Python which I suppose it's not related to a network connection. I tried ...
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SSH and router port forwarding Ubuntu Server 16.04

I'm pulling my hair out trying to get SSH to work through my router/firewall, tell me if I'm missing something... Fresh install of Ubuntu Server 16.04, left SSH config alone, and created keys. Able ...
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iptable matching rule for STUN/TURN traffic

I am looking for finding TURN/STUN packets coming on a 443 port. According to the TURN RFC, Bytes 46 to 49 are TURN packet magic cookie '2112a442'. Here is the screenshot from wireshark where I found ...
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DNAT with port change not working

I'm using this command to establish NAT on my VM container: iptables -t nat -A PREROUTING -d ${MAIN_IP} -p tcp --dport ${2} -j DNAT --to-destination ${SUBNET}${3} with MAIN_IP being main server's ...
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16.04 iptables NAT weird behavior keeps working when removed

root@p10:/proc/net# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 16.04.3 LTS Release: 16.04 Codename: xenial OVH Public Cloud Server, on ...
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Ubuntu 16.04. How to establish both internet and LAN connections at the same time

I have two network devices connected to my PC. 4G USB Stick(enx0c5b8f279a64) 192.168.8.1 Eth Adapter (enp0s10 192.168.50.20) is connected to a DIR-300 router(192.168.50.1). /etc/network/interfaces ...
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Make a machine a NAT router

I would like to create the following network: Internet ---- Host machine ---- VM1 ---(local network)-- VM2 with VM1 acting as a NAT router. VM1 and VM2 run Ubuntu via VirtualBox. To achieve this, I ...
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lxd container with openvpn server does not apply iptables nat rule

I'm trying to setup openvpn on one of my lxd containers to allow access to the container network. The server seem to work and I can access (ping) containers which have a static route pointing to the ...
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Why do all my 16.04 servers in VirtualBox have the same IP address (10.0.2.15)?

On half a dozen separate 16.04.3 servers, all running NAT for the network connection, when I run ipconfig I get back 10.0.2.15 as the address for each machine. Each machine should be getting a DHCP ...
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VirtualBox DNS Specific Port Forwarding

Here is my problem; I have virtual-box running on Ubuntu 64 bit (17.04) and I have multiple virtual machines (all Ubuntu 64 bit). I want to forward port 80, 25, 143 and 22 to all of the virtual ...
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how to view the interfaces for each connection in the nat table?

I've used cat proc/net/ip_conntrack to view all the connections related to the NAT table on the device. But this doesn't give any information with respect to the interface used and the type of nat for ...
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ubuntu iptables NAT & Router & Port Forwarding

I would like to forward the ssh port from ubuntu-fw (firewall) to ubuntu-server1. | Internet | --- | Router (hardware) | --- | ubuntu-fw | ---- | ubuntu-server1 | Router (hardware): Fritz-Box ...
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How to create a non-nat access point with nmcli?

I am trying to create what is essentially a home router with nmcli. I would like the client devices that connect to be on the same subnet regardless of whether they connect with ethernet or wifi. ...
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NAT using iptables on Ubuntu 16.04 doesn't work

I used to use Ubuntu 14.04 trusty for our NAT server (build on Google Cloud Platform), but recently I tried to use the Ubuntu 16.04 xenial. I configured perfectly same as I've done in 14.04, but it ...
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