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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AWS yum does not work from private subnet (does work from public)

I have a VPC with a private and a public subnet - each containing an identically built RHEL7 server. I believe the VPC is set up correctly (see following). However, the public server can use yum and ...
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9 views

Exchange Server 2013, Database Availability Groups, NAT, and High Availability

Dilemma here I want a high availability/failover solution for people accessing outlook anywhere or exchange from outside the network. I have 2 exchange servers (EXCH1 and EXCH2) that have Exchange ...
0
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1answer
13 views

how to enable incoming connection from outside your home network, without a router?

I have a simple question. I dont have a router. i connect to the internet through a usb dongle or through hotspot from my android phone. The usb dongle connects to a 4g network, i use a prepaid sim ...
3
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2answers
1k views

sonicwall vpn and NAT

I have a site-to-site VPN set up with a vendor. Let's say the tunnel endpoints are 192.1.1.101 on my side and 192.1.2.0/24 on the vendor's side (which get's NATted to their LAN of 10.x.x.x). This is ...
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1answer
13k views

Asterisk and SIP behind NAT

I am trying to Setup an Asterisk-Server to accept calls from a client in an other Network. The Server and the client are behind an NAT. I have already activated STUN on the client, but I am still ...
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4 views

Connecting two OpenVZ internal networks so containers can see each other

I have two OpenVZ Hosts with containers on them. This is the current layout: Host-A: (eth0 (connected to internet), eth1 (connected to Host-B)) Host-B: (eth0 (connected to internet), eth1 (connected ...
0
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1answer
20 views

How to NAT multiple Compute Engine Instances in Google Cloud?

We are spinning up Instance Groups that have an auto-scale policy. We have a need to make outbound connections to a server hosted in our Enterprise echo-system and they allow only whitelisted URLs. ...
2
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2answers
56 views

How can I connect remotely to our network from behind a double NAT?

Having successfully set up my home office network for remote access via OpenVPN, I would now like to do the same thing at work, however I am double natted. There is a central router maintained by ...
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3answers
2k views

Configure hairpinning on Cisco 871 IOS 12.4(15)T4?

I'm a newbie to IOS. In the past I've used consumer routers which seem to have the smarts to automatically route requests to internal hosts addressed by their public name back to the internal network. ...
3
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4answers
920 views

How can private IPV4 addresses get past iptables NAT (tcp RST,FIN)

I've got a router performing simple NAT translation using iptables iptables -t nat -o -j MASQUERADE This works fine almost all of the time except for one particular case where some TCP RST and FIN ...
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13 views

How to completely change source IP address on a linux box with iptables and have the response be returned [closed]

I can successfully spoof SRC IP with this iptables rule: iptables -t nat -I PREROUTING -s HOME_PC_IP -p 80 -j SNAT --to 1.1.1.1 Tcpdump shows this: 23:04:57.822993 IP HOME_PC_IP.37832 > 1.1.1.1....
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1answer
4k views

cisco ip nat / port forwarding

I have been trying to get port forwarding working with a newly installed cisco router. I cannot seem to find where my fault is and have been looking for quite a while. The relevant section of my ...
2
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0answers
36 views

IPTables DNAT Exemption

TL;DR - I'm looking for a way to send all my external traffic through a proxy server but not send all my internal traffic through a proxy server. How can I achieve this? My end goal is to forward ...
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1answer
32 views

I can't access my home server using my public IP from local network [closed]

I've seen this question I can't access my public IP from local network but I think it's different I have a Vodafone Spain router from Huawei, model HG253sV2. In my local network I setup a HTTP ...
0
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1answer
30 views

ACL NAT'ing on Cisco ASA 9.2

I'm trying to implement (P)NAT on a active/standby pair of 5525X running v9.2 I need to NAT an ACL not an object and I've been unable to work out how to do this. The ACL is access-list 3G_traffic ...
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1answer
1k views

How does one configure UFW to allow private DNS requests, but block DNS requests from internet

I have an Ubuntu Server 12.04, with two network cards: eth0 is connected to the internet eth1 is connected to a private network (192.168.10.1) The server is configured as a gateway and hosts DNS ...
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0answers
19 views

unable to connect to webserver from LAN (access from outside is fine)

We would like to give both our customers and coworkers a single link (subdomain.ourdomain.com) to access a common web application. I set up a web server on a machine connected to LAN, it's accessible ...
3
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5answers
617 views

Router limits network performance but its CPU load isn't 100%

I'm using a PC Engines APU device running FreeBSD as a NAT router. The setup is very usual: one WAN connection and one LAN connection. Theoretically, WAN connection is 800/40 Mbit/s and the LAN one ...
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0answers
5 views

Windows 10 - NAT - Port forwarding & IP masquerade [migrated]

I'm looking for a way to get iptables functionality in windows 10. I enabled IP routing and I need to forward tcp data to another host (port 8080) and then forward his response while masquerading IP. ...
2
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1answer
2k views

How to make sysctl network bridge settings persist after a reboot?

I am setting up a notebook for software demo purpose. The machine has 8GB RAM, a Core i7 Intel CPU, a 128GB SSD, and runs Ubuntu 12.04 LTS 64bit. The notebook is used as a KVM host and runs a few KVM ...
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0answers
8 views

Convert 8.3+ NAT to 8.2 Cisco ASA

The following NAT rule setup works on 8.3+: nat (inside,outside) source static inside_net inside_net destination static vpn_net vpn_net no-proxy-arp route-lookup However, trying the same on 8.2(5) ...
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1answer
106 views

UDP hole punching still required in IPv6, even without NAT?

Background (skip ahead for question) IPv4 needed NAT for address conservation. The firewalling properties of NAT were also beneficial for security. IPv4 NAT firewall rules are "block incoming packet ...
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1answer
4k views

iptables forward rule not working in openwrt

I am trying to apply some iptables forwarding rules in openwrt. Here is my scenario - My server has two cards ath0 and br-lan. br-lan is connected to internet and ath0 to private network. The other ...
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14 views

Watchguard - Does SNAT and NAT Play together

Whilst I'm yet to try this because I'm affraid I'll loose access to my watchguards external interface I would like to know if the following scenario works? We currently have a bank of external IP's ...
0
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1answer
27 views

Centos 7 firewall-cmd settings not persisting

I have decided to do a bit of spring cleaning, and am doing a refresh of some of my underlying infrastructure. One of the critical components I am overhauling is the Network Gateway server. I updated ...
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0answers
21 views

IPsec with EC2 client and Elastic IP, but nat_traversal=no

After researching this quite a bit, I feel I may be asking the impossible here, but I thought I'd give it a shot. I'm trying to configure an Openswan IPsec client on an EC2 server (inside VPC, if it ...
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2answers
2k views

Unable to PPTP through NAT on Cisco 881

I'm trying to connect to a PPTP server which is sat behind a Cisco 881 NAT router. The server is running Ubuntu Server 12.04 and is running Poptop pptpd as the PPTP daemon listening for connections. ...
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1answer
47 views

How to mangle IP addresses based on time using iptables

I want to change my IP addresses based on time not urls. Following is my iptable rule to mangle IPs I have : sudo iptables -t nat -A POSTROUTING -o em1 -p tcp --dport 80 -j SNAT \ --to ...
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1answer
40 views

Two NIC must for RRAS VPN/NAT Server??

I am having one Server "windows server 2012 r2" with single NIC I have few client outside my network So, I need to configure RRAS server with VPN/NAT for remote client Does RRAS server required ...
0
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1answer
1k views

Cisco 887VA Port Forwarding Not Working

I have a Cisco 887VA connected to our BT Business Broadband line. We also have another modem on a seperate connection which also handles our DHCP. The Cisco is plugged into our network switch, as is ...
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0answers
9 views

Logging NAT translation errors on Cisco IOS router? (port scanning, bogus 'established' packets)

We have a NAT setup with port mappings to internal Webservers and DNS servers. If someone tries to connect, say, to port 22 (SSH), then those packets are dropped simply because there is no static NAT ...
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17 views

What is reliable way to set up microservice architecture with IoT devices?

There is many ETH connected devices, behind many different NATs. I want to be able to send and receive messages: Server <> IoT devices using REST-like services. My current solution is to have SSH ...
0
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1answer
59 views

why teredo IP Address keep changing?

I managed to configure teredo on windows 7 but I come up with one problem ... teredo IP address keep changing . I noticed that terendo stat keep change too , it moving from dormant to enabled and ...
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0answers
39 views

IPTABLES - Prerouting Issue - Port 443

I have a NAT server setup with 4 servers behind it. I have a PREROUTING entry to allow https/443 INTO my environment, specifically to to a web server running IIS on port 443. This works fine. ...
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2answers
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Routing multiple WAN subnet on a single interface SonicWall NSA 2400

In my current infrastructure I have the following setup : ISP LINK 1 (64.30.24.128/26) ----|X3--sonicwall--X0|----LAN (64.30.24.128/26) X0(LAN) is configured as Mode/IP Assignment: Transparent ...
0
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1answer
24 views

Nat or Static Route in pfsense

I installed PFsense on VMware with two interfaces. 1.WAN -> 192.168.1.110 ->Bridge Getaway->192.168.1.1=>Modem IP 2.LAN -> 10.1.1.1 ->LAN Segment how config Nat and ...
2
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1answer
39 views

Can't access server on loopback address, only on private address

I am running a rails web app server bound to 0.0.0.0 on port 80 like so: sudo rails s --port=80 --bind=0.0.0.0 I can access it at my private address http://192.168.0.13/, normally I can access at ...
0
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1answer
35 views

Forward outgoing traffic for port to another server using iptables

I'm trying to forward outgoing traffic 194.97.114.3:2010 to another server but with no luck. netstat -anup gives me udp 0 0 94.23.28.183:44174 194.97.114.3:2010 ESTABLISHED ...
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2answers
35 views

iptables for internet connection sharing

Objective: I am working on an embedded Linux device with the following network configuration. Interface-1: 'wlan0' acts as an access point. Interface-2: 'eth1' connected to Internet. Interface-3: '...
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12 views

Turn-key VPN setup to make server behind firewall accessible

I am looking to a solution for a following problem - on a location A, I am allowed to use as much bandwidth as required, with the caveat that I am constantly behind a firewall without a public IP ...
0
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1answer
23 views

Cisco 1921, SMTP, and NAT on multiple Exchange Servers

In a LAN environment, I have 3 exchange servers that have been deployed for high availability and failover in case one of the 3 servers becomes unavailable. Currently, my NAT settings only send ...
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0answers
33 views

OpenVPN NAT gateway on Debian, no traffic

My Debian server is successfully configured to connect to "HideMyAss", using OpenVPN, has internet access, receives HMA IP and still sees the computers on the LAN. I'm trying to configure the other ...
3
votes
1answer
134 views

Create a multi-homed linux load balancer with two internet connections and one LAN connection

OK,... this has possibly been answered, unfortunately, I have not found anything that looks like it might be the resolution. Ive looked at these pages and they have some useful information, but not ...
0
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2answers
79 views

Can a DNS server uniquely identify a specific client device behind a NAT?

I've been playing around with this Netflix Proxy setup (https://github.com/ab77/netflix-proxy), and I noticed that it might be possible to use the DNS endpoint to function like a hotspot with a walled ...
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0answers
26 views

VoIP NAT to connect to companies of the same ip address range together

I am currently using packet tracer to configure the network for Company A. I have configured DHCP and telephony service successfully but the problem I'm facing is when company A tries to contact ...
0
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1answer
19 views

Connecting to Azure Server hosted website via NAT'ed address

I have an Azure server with multiple websites published through IIS and I am wondering if there is a way to change the URL outside clients connect to without changing the name of the server. I have ...
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1answer
138 views

How to combine multiple route hops using one (pfSense) router?

I am trying to come up with a way to consolidate two routers into one. I have the following network configuration: LAN <-- a/24 --> NAT Firewall <-- x/29 --> Router <-- y/30 --> ...
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1answer
1k views

how to setup sonicwall tz210 to port forward packets received from external ip to another external ip

i have a sonicwall tz210 on a fixed ip, say ip1. And then i have, let's say a legacy server, with external ip ip2, which sends data to ip1 (and I have another server on ip1 behind the sonicwall which ...
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0answers
34 views

cisco asa public server nat issue

I have been tasked with some ASA configuration coming in a few weeks, and to test out some configuration options I have setup a web server on my local network which I would like to be able to access ...
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0answers
29 views

Transferring data to Active FTP server fails from DMZ but works fine from LAN

I know there are a ton of similar questions already, but I've read through just about everything I could find and am still having trouble resolving my specific issue. Problem: I am having difficulty ...