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Questions tagged [nat]

In computer networking, network address translation (NAT) is the process of modifying network address information in datagram (IP) packet headers while in transit across a traffic routing device for the purpose of remapping one IP address space into another.

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NAT rules for VPN routing to public IP in local network

I'm trying configure a test VPN setup to route pings to an instances public IP. A corporate vendor we are connecting to has reserved all private space on their side. I'm not sure what NAT rules I need ...
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How to NAT private IP to public IP through virtual LAN in centos 6

Guys i am having an issue with NAT on centos. In my LAB Centos is configured as a router. I want to run my local system (example: 192.168.1.45) apache server on live IP (example 112.100.4.34). This ...
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Google Cloud NAT internal IP

I have a running cluster on Kubernetes with GCP, and some services running on App Engines, and I'm trying to communicate between them without being able to access the App Engines from the outside. I ...
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Can I determine the client IP after traversing NAT?

I have the squid proxy running just behind my cable modem, in transparent proxy mode. Between squid and client computers is my wireless router. All of the proxy logs show the router's IP address, and ...
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Any drawbacks to to using nat MASQUERADE with no source constraint (in a typical simple VPS setup)

Situation: A VPS already serving web pages via nginx. Now I am adding OpenVPN for roaming devices to this VPS. One installation for the VPN guide suggests adding this MASQUERADE rule - iptables -A ...
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Mobile IPSec VPN works but does not follow 302 redirects

I have a very odd problem, I have a pfsense firewall that is serving IPSec VPN to my mobile phone (Pixel XL, Strongswan VPN). The VPN works fine in that I can connect, reach the internet and the ...
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Redirecting UDP to local port, the reply packet not SNATed

I ran dnscrypt-proxy or tor on Linux listning on [::]:1053 to server DNS. I wanted to make all my Linux host's DNS queries transparently use that proxy. This is what I found on Internet how to ...
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In AWS, why is an EC2 behind NAT gateway in private zone said to be safer than one in public subnet?

I've been running four servers on AWS for a few years. It's for a hobby project. All servers live in the same subnet in the same VPC. To simplify the management of accounts and permissions, I've ...
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How to forward public_IP/dashboard of an HTTP server to private_IP/dashboard?

I have a website which is accessible internally via http://private_IP/dashboard. The public IP forwards all traffic to the private IP. http://public_IP -> http://private_IP. This works. However, ...
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43 views

Docker Host with multiple VLANs

Background Information I have a server with one physical network interface that is running Docker. This interface is configured as a 802.1Q trunk. To avoid asymetric routing I configured routing ...
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IP address on GKE for egress is IPv6, not IPv4 wth Cloud NAT [closed]

I would like to set a fixed IP address on egress of an application with GKE. In a case of GCE, each external-IP of VM instances is exposed to an external application on connections as 'REMOTE_ADDR'. ...
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VM: bridge connection won't work but NAT is okay

I messed my server configuration up when trying to set a port scan protection on my Debian on VirtualBox. I did it while being connected via Bridge and now I have no internet connection anymore. When ...
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Kvm guests cannot access internet

I have a kvm host and 4 kvm guests using default kvm nat networking. Using ip pool 192.168.100.0/24 for kvm guests. It seems that for some reason masquerading/or something else is not working properly ...
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TCP KeepAlives with NAT?

We have a Network set up like this: MQTT Client -- TCP Forward (Netscaler) -- TLS Termination + TCP Forwarding (HAProxy) -- MQTT Server For several reasons we needed to turn on TCP KeepAlives in ...
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pfSense - NAT not working

I have a pfSense on Proxmox VM. I have two IP addreses configured: WAN: xx.xx.88.24 -> public IP accesible from internet LAN: 192.168.1.100 -> corporate intranet I want to access an internal ...
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running VPN and NAT on a Windows server that is connected to internet using a static IP address

I have a windows server 2008 VPS, and I want to have a couple of VPN account that have access to this server and the indernet through the server (using the server's IP access to the internet). so I ...
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How to remedy TLS handshake issue while forwarding packets between two NATs?

There is a local network with Wifi router working as NAT server, which is connected to an ISP. It's needed to place a firewall between the router and ISP which filters incoming and outcoming traffic, ...
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If I have a NAT instance on my AWS console how can i find instances in my account using it for accessing internet?

I have a NAT instance. I will be rebooting it, since I am new to this project i am not sure which instances are using this NAT to access internet. How can I find those instances.
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OpenVPN without NAT or DHCP

I am trying to setup an OpenVPN server similar to LiquidVPN.com. WIth their VPN server when a client connects it receives the public IP address of the server. All network traffic to the public IP is ...
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1answer
90 views

Can a GCP custom route point to a destination URL (as opposed to an IP range)?

Objective I need to access an external API (say, www.api.com) from an App Engine app. The external API requires source IP whitelisting. Problem App Engine does not allow me to reserve external IP ...
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46 views

Traffic does not get routed through vpn

Having set up a tinc VPN node properly (the vpn Connection works): I have set the following options net.ipv4.ip_forward = 1 iptables -t nat -A POSTROUTING -o ens2 -j MASQUERADE If I then set the ...
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153 views

Unable to NAT TFTP traffic because iptables is not forwarding the return connection to the client despite TFTP helper creating an expectation

The Problem I have a TFTP server (Machine 'S') and a TFTP client (Machine 'C') on different subnets. They are connected via a router( Machine 'R'). All 3 machines are Debian 9/Stretch. The router is ...
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Router's Parental Controls Really Block All Internet Traffics?

I am using Asus 4G-AC53U router. When I turn ON "Parental Controls" to block a client's Internet access, does the router really block ALL kinds of Internet traffics including system's service (such as ...
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Allow GRE (IP protocol 47) over Linux router NAT for a subnet

I have network setup as shown below: The VPN server running is windows 2012 server default VPN, which uses GRE protocol. I am able to have VPN connection to that remote vpn server, from my intranet ...
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1answer
47 views

different firewalld rich rule behavior in kvm host compared to kvm guests

I have a CentOS 7 KVM host with a single public IPv4, which is housing multiple guest OS's and acting as a firewall / gateway for guest network 192.168.1.0/24 / nat. I want to run a webserver of 1 ...
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325 views

Connection refused when accessing container from local network through reverse proxy

I am running Proxmox VE on a root server. There are several virtual containers, on of them acts as a reverse proxy who does TLS termination. On the proxmox machine iptables handles port forwarding ...
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Forwarding Fragments with IPTables / FirewallD

I have a linux (openSuse Leap 15.0) computer that's connected to a cable modem using PPoE (hopefully not relevant to this. EDIT the ppp0 interface has an mtu of 1492 but the eth0 interface it is "...
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1answer
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NAT: Figuring out IP of broken down machine

I have a machine that was behind a natted router. Unfortunately its harddrive broke down, so I had to replace it. I have port 22 forwarded to it (in the router provided by the ISP) for remote ...
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38 views

Source NAT on Juniper SRX300

I'm having issues setting up the Source NAT on my SRX300 firewall. The firewall is connected to an LC-panel through a fibre optic cable in port 0/6. I have set the public ip on that interface and have ...
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1answer
143 views

Creating a NAT gateway with Terraform fails with an error

I'm running a private GKE cluster and want to add a NAT Gateway so I can create firewall rules from requests coming from the cluster (by default, the public IP's for all nodes are ephemeral, thus hard ...
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CentOS iptables NAT, client cannot connect to WAN from LAN

I have the following configuration: 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 ...
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View traffic flowing through NAT machine

I have been put in charge of an HPC cluster recently and the last admin didn't do a great job of documenting everything. We got a notification from our IT Security team that our head node has been ...
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Can't configure Dante

Config version: 1.4.x I get "Connection refused" after default 30 seconds in curl and "Connection Failed" immediately in FoxyProxy. Dante config: logoutput: syslog stdout /var/log/lotsoflogs ...
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179 views

Ipsec nat-traversal on port 4500

What is the point of switching the traffic on port 4500 in Phase 1 of IPSec negotiatons From 5th packets onwards? Since the NAT Is already detected in packet 3 and 4 itself, can’t we simply continue ...
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Can I access my VMware workstation intranet VMs through a public IP address

I have a Windows Server with a public IP address (102.1.1.1) and I've installed VMware workstation on it, creating several VMs on it. The VMs use intranet IP addresses, such as 10.0.0.1, 10.0.0.2. ...
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MASQERADE iptables rule not being hit inside docker conatiner

I am trying to route traffic via an OpenVPN tunnel which is running inside a docker container, but cannot get NAT to work +---------------------+ +-------------------+...
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103 views

CISCO ASA tunnel is up but no traffic

I have reviewed the very similar questions to mine, but my scenario seems different. ASA Version 9.7(1)4 I had a VPN site-to-site ikev1 connection from a remote network in AWS to a remote network ...
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1answer
84 views

Forwarding traffic between two interface

I have a Linux box with two interfaces: ~#ip -4 addr show scope global 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 inet 192.168.45.101/24 brd ...
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1answer
38 views

NAT on SonicWall for Debian server

I'm writing because i have a very strange issue with a newly installed debian 9.5 server. This server is behind a NAT made with a SonicWall firewall that assigns a public dedicated address to this ...
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1answer
32 views

Port forwad public ip port to internal server on different interface

Hello I am trying to port forward a public ip:port I have on a wan interface to a server on my lan my server has two interfaces ens19 [WAN] ens18 [LAN] I then have another server connected on the ...
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1answer
96 views

NAT gateway for ec2 instances

I have a public subnet with ec2 instnaces. The route table has 0.0.0.0/0 IGW (Internet Gateway) as default. I tested adding a public IP address to my instance (104.27.142.41/32 as reported by curl ...
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1answer
94 views

NAT setup on AWS

This might sound ridiculous for some, but am trying to setup NAT on lightsail so that I can access my private ec2 instances which are connected using VPC peering. Suppose if 172.31.x.x is my ...
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2answers
379 views

What is the AWS NAT Gateway?

I'm not sure what caused it, maybe Elastic Beanstalk, but at some point AWS created me a "NAT Gateway" which costs more than my EC2 server instances themselves. What does it do, why does it cost so ...
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1answer
73 views

How to split outbound traffic by destination IPs on aws with static IP?

Conditions are below. Use static IP for all outbound traffic. Send traffic through VPN Connection if it has the specific destination IPs. Send traffic through the Internet if it has NOT the specific ...
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1answer
190 views

Port-forwarding traffic to remote server using iptables

I'm struggling to set up an infrastructure where MySQL replication traffic from an Amazon RDS instance is forwarded over an OpenVPN link to a second server. There is an Ubuntu EC2 instance running ...
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For many different TCP hosts, how can I differentiate and route them from the same external IP?

I realize I may be asking the impossible here -- At the moment I use too many elastic IPs, and they cost money. Not only do they cost money...but in a disaster scenario, it takes time to reattach 25 -...
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ESXi 5.5 VM accessible from outside but no outgoing connections

I have an ESXi 5.5 dedicated host with several VMs. Each of them has internal address 192.168.0.x and is reachable via TCP on public address (public class, so I can access them on the internet via ...
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333 views

Add-NetNatStaticMapping not port forwarding to local VM

I'm running windows 10 build 1809 and have hyper-v installed. I have a Linux machine running behind a NAT with internet connectivity working on IP 10.0.5.5. I basically followed instructions on the ...
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1answer
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Test connectivity to NAT Gateway over firewall.

I created a VPC in aws and added a NAT Gateway so my instances in the VPC can consume other resources on the internet. Some of these resources belong to a 3rd party and are behind a firewall for ...
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Routing/NAT with Network Protocol Transformation

I'm looking for a way to accept multiple TCP based protocols on any port, then transform and redirect them all to HTTPS and send them over the internet to a server. (The "Server 1" is mine with ...