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Ask Ubuntu

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).

103 questions
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Ubuntu routing between two interfaces has very low speed

I'm routing traffic from enp5s4f0 (private) to enp7s4f0 (internet) this is my interfaces file: internet interface auto enp7s4f0 iface enp7s4f0 inet static address 10.192.129.164 netmask 255.255....
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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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9 views

Shorewall NAT/SNAT Two NIC

I've Ubuntu 18.04 installed with two LAN Card eth0 is connected to the internet and eth1 internal network. eth0: 192.168.137.10 (connected to internet) gateway: 192.168.137.1 eth1: 192.168.0.250 ...
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21 views

Ubuntu Sendmail on internal XenServer not working

I have set up a XenServer in my home network. It's using an internal IP-Adress and is published via NAT and Web Protection. I have now a virtual machine with ubuntu but I am not able to send mail via ...
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33 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,...
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29 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 ...
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20 views

How to ping an one ip address and be routed to another one

I need some routing in my machine. For example, I ping ip address 172.16.x.x and want it to be addressed to 10.246.x.x on my local machine How can I do that?
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279 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 ...
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34 views

hostapd and nftables

I successfully installed hostapd and dnsmasq on my Ubuntu desktop with a PCI wifi card. Wifi clients can connect and get IP addresses with no problem but traffic to internet does not work. I use ...
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19 views

how to redirect and load balance locally generated packets through iptables

Here is the scenario I am working on. I have sslh listening on 443 which redirects https traffic to 445 and TURN traffic to 3478. I also have 6 TURN servers listening on 3478 to 3483. I wish to load ...
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137 views

iptables setting strongswan ubuntu 16.04 VM

I want to set a VPN Tunnel using StrongSwan to make my VM Linux as a router. The illustration is like this: I have a server with Public IP 111.111.111.111. Inside it I installed Ubuntu 16.04 VM with ...
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158 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 ...
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43 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 ...
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254 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 ...
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33 views

Setup up nat routing during auto install preseed late-command

As part of the script I run as a late-command in pressed (unattended installation disk) I have added the following: set up firewall if [[ $(ufw status | grep 'inactive' = inactive ]]; then ufw ...
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446 views

How to set NAT by ufw on ubuntu 16.04?

I am green to Ubuntu. I tried the method of "ufw Masquerading" to set NAT. But I can't connect the Internet through NAT with MacBook air. Here is the information I used to connect the Internet: IP ...
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38 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 ...
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157 views

Access an instance in the private subnet from a public instance

Scenario: 2 instances(ubuntu xenial 16.04) in one VPC out of which one is in a public subnet(has an internet gateway) and the other is in a private subnet(has a NAT gateway). How do I access the ...
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285 views

Load balancing WAN connections

I've looked through a lot of the posts here but I'm not really finding what I'm looking for. I want to set up load balancing more or less as shown here: https://serverfault.com/questions/93678/load-...
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1answer
552 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 ...
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243 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
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1answer
598 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 ...
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1k views

No internet access using NAT on virtualbox 5.1.24 with windows 10 host and ubuntu 14.04 guest

I don't get connection to internet using NAT on virtualbox 5.124 with windows 10 host and ubuntu 14.04 guest. As I read from the virtualbox site I should be getting internet access configuring NAT ...
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2answers
365 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 ...
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32 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
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1answer
3k 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 ...
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1answer
583 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
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2answers
8k 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
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1answer
451 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 ...
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178 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
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1answer
57 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
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1answer
354 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 ...
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1answer
397 views

Ubuntu 16.04 desktop vm is the only OS that will not register on the local network

I have several linux & windows vms(vmware) running on windows 10 pro host, in vmware workstation 12.5. All vms are configured the same way in workstation, but the Ubuntu vm is not discovered in "...
0
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0answers
577 views

Virtual Box in Ubuntu host machine - NAT network not working

I'm trying to get some virtual machines running in Virtual Box and I want to use the "NAT network" network setting, but I can't get internet connection to work. Is there some setting I need to adjust ...
0
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1answer
454 views

Block All Traffic on Specific Interface

I was trying to block all traffic on a specific interface (which is external wireless) except browsing by using ufw: sudo ufw enable sudo ufw deny out on wlx00252245ed96 sudo ufw allow out on ...
1
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1answer
187 views

Could'nt punch through NAT(or NAT not in place)

I am trying to install Ethereum for Ubuntu 14.04. I followed the mentioned thread. This is the error description I am getting! Maybe the problem is with the proxy bypassing settings. If someone could ...
1
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1answer
341 views

Forward packets from bonded LAN interface to WAN

I am not able to route packets between the lan side of my ubuntu server and the wan side. I'm looking for some assistance. I have 5 ethernet ports on my server - 1 onboard (eth0, used for wan) and 4 ...
0
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1answer
345 views

Cant connect an ESXI host behind an ubuntu NATusing Vsphere

I have 2 NIC's on ubuntu ; eth1 (pci-e based net. card) > WAN (router) and eth0 (onboard) > server (onboard) (no cross cable) so what I want is to access both ubuntu (vnc and ssh) and esxi server (...
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74 views

Keep the same port number for forwarded packets

I have the following IPSEC setup: LEFT (IPsec) <===> MID (PPP) <=ppp=> RIGHT (IPsec+PPP) All running Ubuntu 14.04 LTS. MID communicates with RIGHT in PPPoE (marked ppp). Now... IPsec servers ...
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1answer
58 views

File copy fails over Ubuntu Gateway using NAT

I have managed to successfully set up NAT on my Ubuntu 14.04.4 machine so that my computer acts as a gateway for a computer connected on the internal interface (eth0) to the external interface (eth1)....
0
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1answer
2k views

Port forwarding with DNAT not working

I want to forward my local port 2221 to a remote machine (192.168.2.100), where ssh listens on port 2222. Connecting to the remote machine works: ssh -p 2222 192.168.2.100 user@192.168.2.100's ...
0
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1answer
551 views

ubuntu guest system can't ping Window 8.1 host

I have a Window host 64bit 8.1 at home ( connecting to Internet via home router), I recently installed an ubuntu 32 bit guest on VM Windows player ( latest version) with NAT. ifconfig -a on ubuntu ...
-1
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1answer
585 views

Does rsync over ssh require use of UDP?

I have a remote rsync backup to a server running over ssh, using NAT to specify a non-standard high numbered port on the router. Is it ok to only open the port on the router, and the ssh port on the ...
0
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1answer
426 views

How change Gateway of subnet ( private network, Internal) on MAAS

Ubuntu : 16.04 MAAS: 2.0.0 beta 3 I need to change the gateway address of my subnet( private lAN,Internal which is 192.168.120.1) to ip address of my region/rack controller( internal ip 192.168.120....
5
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1answer
141 views

Accessing a LAMP webserver that's behind a Ubuntu VM acting as a firewall

I currently have two VM's set up in the following manner: /-----------------------\ /-----------------\ | Ubuntu VM | /---------------\ ...
1
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0answers
3k views

Setting up NAT forwarding using iptables on ubuntu server 14.04

I have a server with 2 ethernet interfaces(em1 and em2). em1 is the internet facing interface(192.168.16.113) and em2 has a static address(10.1.1.100) connected to a switch. I have configured the ...
0
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1answer
96 views

DNAT redirecting to specifc port is not working

I want to redirect ssh by port using DNAT, and i do try to ssh it through the command > username@IP_ADDRESS:10003, and I got this message: ssh: Could not resolve hostname IP_ADDRESS:10003: Name or ...
0
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1answer
750 views

Is it possible to define a fallback gateway server?

I'm using iptables to implement forwarding on one server, that is support to forward traffic from an internal network to the internet (tutorial: http://www.revsys.com/writings/quicktips/nat.html) On ...
3
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1answer
400 views

configure iptables to redirect traffic to a specific IP address

I have just began using iptables. I have a server with a public ip address (A.A.A.A) wich is hosting a Virtual Machine (B.B.B.B) on local network. I want to redirect all inbound traffic on the port ...
0
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1answer
160 views

How to resolve multiple hosts inside a NAT firewall

My apologies if this has been asked before, but I can't seem to find a complete solution. I have a hosted sub-domain at no-ip.com with a wildcard DNS option enabled. On my end I have a firewall port-...

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