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).

Filter by
Sorted by
Tagged with
0
votes
1answer
20 views

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 ...
0
votes
1answer
342 views

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 : ...
0
votes
1answer
609 views

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 ...
0
votes
0answers
18 views

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?
0
votes
2answers
235 views

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 ...
0
votes
0answers
31 views

How do I redirect traffic from the virtual tun interface to the LAN?

How do I redirect all traffic from the virtual interface (tun) to the LAN? Linux UBUNTU 16.04, eth0 (wan) eth1 (lan) virtual tun (tun2socks) adapter available I need eth0 (wan) -> tun adapter -> ...
0
votes
0answers
21 views

Setting up VPN server for windows 10 clients

Desperate for help at this stage. I need to set up a vpn on my Ubuntu server 18.04 for windows 10 clients to connect to over the internet. I installed strongswan but everything ive tried seems to fail....
0
votes
1answer
657 views

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. ...
1
vote
1answer
105 views

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 ...
0
votes
0answers
54 views

How to set firewall iptables for intrnet ip and port to access internet destination ip address

I have two linux servers: serverONE and serverTWO. serverONE has Intranet address :10.1.200.2 serverTWO has two ip address: 10.1.0.12 and 172.8.2.16. And 10.1.0.12 is also Intranet address; 172.8.2.16 ...
0
votes
0answers
43 views

Dual NAT and pptp access

This is my first fast and I welcome everyone. I have a little problem. I bought raspberry pi4. I configured the network as in the picture. image I can't connect from my home (here is rpi) to vpn ...
0
votes
1answer
67 views

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 ...
0
votes
1answer
695 views

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 ...
0
votes
0answers
52 views

How to route traffic on a certain port to another server?

I have the following hardware configuration : BOB, a machine connected to the internet. VM, a virtual machine somewhere on the cloud. PI, a raspberry PI somewhere inside a private network, but with ...
0
votes
1answer
65 views

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 ...
0
votes
1answer
66 views

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 ...
1
vote
1answer
432 views

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....
0
votes
0answers
512 views

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 ...
0
votes
1answer
97 views

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 ...
0
votes
1answer
959 views

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. ...
0
votes
3answers
2k views

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 ...
1
vote
0answers
88 views

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 ...
0
votes
0answers
24 views

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.
0
votes
1answer
2k views

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 ...
1
vote
2answers
59 views

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 ...
1
vote
0answers
736 views

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....
0
votes
1answer
38 views

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 ...
1
vote
2answers
779 views

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 ...
0
votes
1answer
95 views

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 ...
1
vote
1answer
1k views

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 ...
1
vote
1answer
37 views

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 ...
1
vote
0answers
123 views

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,...
0
votes
0answers
44 views

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 ...
0
votes
1answer
831 views

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 ...
0
votes
1answer
1k views

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 ...
0
votes
0answers
304 views

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 ...
1
vote
0answers
686 views

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 ...
1
vote
0answers
108 views

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 ...
1
vote
1answer
4k views

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 ...
0
votes
0answers
351 views

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 ...
0
votes
1answer
3k views

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 ...
0
votes
2answers
814 views

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 ...
1
vote
0answers
40 views

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 ...
2
votes
1answer
4k views

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 ...
2
votes
1answer
2k views

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. ...
5
votes
2answers
17k views

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 ...
1
vote
1answer
862 views

Ubuntu: VPN kills NAT

Output: Wireless Info Script Connection is ISP router (DHCP) - eth0 192.168.1.91 - wlan0(NAT/DHCP) 192.168.5.1 I'm using hostapd to bring up the AP, /etc/network/interfaces to create interface and ...
1
vote
0answers
364 views

Can't connect CSGO-Server or SSH on my Ubuntu 16.10 VM

I've installed Ubuntu on Orcale VM VirtualBox. The internet connection is over NAT. I've tried to set it to Bridged Adapter, but then I don't have any access to internet on Ubuntu. I've installed ...
0
votes
1answer
62 views

Is it possible for a network administrator to detect easily if I am running Ubuntu on VirtualBox using NAT mode for networking? If yes how to hide it?

I want to run linux on virtual box on my computer. How do I run it without getting detected?
0
votes
1answer
674 views

Port Forwarding to Windows Desktop from Ubuntu Laptop?

I currently have a weird setup. I forgot to get a wireless card for my Windows 10 desktop so I am currently sharing my Ubuntu laptop's wireless internet with my Windows desktop via ethernet cable. I ...