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 vs Proxy server

I have installed squid proxy server to hide our network ips after some time it becomes slow then I read through NAT rules to achieve what I want by proxy server. As per this link the difference ...
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471 views

Router/Gateway with host-header capability

Can anyone direct me what to look for to get a Router / Gateway / Firewall for my home-office enviroment to be able to run multiple e.g. Webserver on port 80, with one public ip. I know it can be done ...
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334 views

iptables alternative for nat in windows

When setting up a comms server I usually use iptables in linux to forward any incoming connections on a particular port to another server, e.g. Chain PREROUTING (policy ACCEPT) target prot opt ...
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87 views

Multiple routes and gateways with NAT

My setup is a VM host with two network interfaces where I want to use one as private/internal and the other one as public (which will get a public address on the host), where all the NAT magic to the ...
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1answer
1k views

iptables port forwarding to vmware workstation guests on NAT vmnet [closed]

Try as I might, I can't get this to work now for 2 days. Your move, internet. I want iptables to transparently forward (localhost) 192.168.1.40:2222 to 192.168.2.22:22 and I don't want ...
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1answer
151 views

Cisco ASA 5505: Created a faulty NAT rule. Can't reach the ASA

I was trying to create a NAT rule to reach my internal web server from inside the LAN. Something must have gone wrong. Now when i try to reach the ASA through https://192.168.1.1 the response is from ...
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2answers
118 views

IPtables NAT puzzler: Why is traffic from the firewall host being NATed even though it's not coming from one of the prescribed source addresses?

I run a small network where a linux web/mail server also provides NAT for a collection of windows boxes. One of these windows machines is apparently misbehaving (ZeroAccess botnet even though I can't ...
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2answers
377 views

VMWare NAT releasing SYN packets from guest but not admitting SYN/ACK packets to guest

VMWare Server 2.0.2 Host OS is Windows Server 2008 R2 Standard Guest OS is Windows XP I am using VMWare VMNet8, the NAT network. The VM guests can't see out to the network around the VM host. Packet ...
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1answer
324 views

Ubuntu Server / IpTables / Port Forwarding / NAT

I got referred here from StackOverflow. I'm using IpTables to forward an incoming port on one server to an external server (not on LAN) and the same port. The problem I'm having is that I have to use ...
2
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0answers
293 views

Keepalived failover not working for Static NAT target behind Cisco ASA

I've got a Cisco ASA[0] with a pair of Linux boxes in the DMZ running Keepalived and HAproxy acting as a load-balancing failover pair for another pair of Windows servers, also in the DMZ. I'm ...
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2answers
3k views

How to configure and enable NAT with server core installation

Using Microsoft Server 2012 Core: What is the equivalent core/Powershell command to enable and configure NAT. I have configured NAT on servers with the following GUI steps: Server Manager, Tools, ...
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3answers
309 views

CentOS masqueraded network with iptables clients not connecting: Unable to ping

I'm a novice sysadmin working on a system with a CentOS server masquerading traffic with client machines also running CentOS. Something with the tables got messed up and my clients no longer have ...
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1answer
171 views

How to bind traffic of each NAT client to a external IP address?

I have a NAT router with 2 IP addresses, lets say 111.111.111.111 and 222.222.222.222 associated with the interfaces eth0 and eth0:1 respectively. I have two servers that connect to this NAT gateway ...
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1answer
1k views

Dual ISP Inbound NAT — Asymmetric routing

routing question here. In a dual ISP scenario is there way to use both external IPs and nat them to a web server in a higher security level? The issue I am running into is on the return path for ...
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2answers
91 views

Connect four Modems having same IP with a single Ethernet Switch [closed]

I have a scenario where i have 4 modems connected to a switch. all four modems have IP address 192.168.0.1(default). i want to connect all of these four modems with a single switch in a way that i ...
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1answer
3k views

How do you NAT Hairpin in IOS 8.3+

As I asked here and duplicated here it appears NAT Hairpinning is the answer I'm looking for to allow internal servers to loopback through the ASA to access external IP's (without using DNS ...
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1answer
952 views

pfsense nat between two internal ip

TL;DR What technology should I use to translate an internal address (192.168.1.10) to another internal address (192.168.1.11)? So that when I access the first I get redirected to the other? Long ...
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90 views

VmWare : listening nat in promiscuous mode

This document describe how NAT in VmWare works. Next picture is from that document. Is there way to configure Virtual Ethernet switch in that way: All packets arrived from nat send to specified ...
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2answers
1k views

Cisco ASA/PIX Can't Access Internal Resources Behind NAT [duplicate]

My servers are natted 1:1 as follows, i.i.i.i maps to x.x.x.x where i is an internal IP, and x is the external IP. From an i.i.i.i machine, I cannot access x.x.x.x resources... What special ...
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0answers
49 views

Zyxell USG200 NAT for local computer using wan address

My WAN public address is linked to the server with NAT. How can I set up the firewall to let all local computer use the same NAT rules for www.mypublicaddress.com address from INSIDE the network? I ...
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1answer
54 views

Lost as to what I'm not doing in setting up a home lan network [closed]

I'm a PC repair tech and this is a problem I've recently been trying to troubleshoot for a customer. Upstairs they have the main router which servers as the gateway and router, both hardwired and ...
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0answers
554 views

Windows Server 2012 R2, multiple Hyper-V Virtual Network Switches for multiple VMs

I want to configure something like this: I have one NIC, and have been given 3 IPs by datacenter, on my server which is running WS2012R2, with 10 VMs on hyper-v. Windows Server 2012 R2 (host) one ...
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0answers
209 views

Why is an ack response being sent to the wrong gateway?

I was trying to determine why a packet forwarded by iptables to my internal lan is returned on the wrong gateway. Having investigated this further, I determined that, at least in the case of one of ...
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1answer
887 views

NAT rules betweek 2 network interfaces (with iptables)

this is the current network that I have: UBUNTU: eth0: ip: 212.83.10.10 bcast: 212.83.10.10 netmask 255.255.255.255 gateway 62.x.x.x eth1: ip: 192.168.1.1 bcast: ...
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1answer
508 views

Understand FTP; Active/Passive with Firewalls and NAT [closed]

I have some basic questions about FTP with firewalls and NAT, I hope someone could help me :) I split them up in different scenarios: Active FTP without NAT Setup: Server 1.2.3.4, Default ports; ...
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1answer
179 views

website not accessible with IIS6 while NAT is configured in Windows 2003

I have Windows2003 server configured with IIS 6. Until now it was working fine, but since I enabled NAT for my users to access the internet via this server, the website becomes unavailable. Note that ...
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61 views

Where can I find the range of IP addresses of my container OpenVZ

I'm looking for the "range of IP addresses of my container"... Where can I find those ? /etc/network/interfaces ? ifconfig ? I don't know and I can't find any answers... I need it for this tutorial ...
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1answer
277 views

Variable host IP address in iptables rule

I am running CentOS 6.4 with OpenVZ on my laptop. In order to provide Internet access for the VEs I have to apply the following rule on the laptop: iptables -t nat -A POSTROUTING -j SNAT --to-source ...
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1answer
3k 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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1answer
136 views

Adding Multiple Interfaces to EC2 Ubuntu 12.04

I have a m1.medium Ubuntu 12.04 instance with two ENI's. I have a VPC setup with a private and public subnet. Private: 10.50.1.0/24 Public: 10.50.101.0/24 I initiated the instance on the private ...
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Amazon EC2 Nat Instance - goes out but not back in

I've followed Amazon's steps and list what I've done. I've created 6 subnets (4 private SN1: 10.50.1.0/24, SN2: 10.50.2.0/24, SN3: 10.50.3.0/24, SN4: 10.50.4.0/24) and 2 public (SN5: 10.50.101.0/24 ...
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387 views

Socksify TCP connections reaching a gateway IP — preferably without iptables

I have Virtualbox installed on Debian with a few virtual machines. I can't install anything in the guests, and I use host only networking, vboxnet0. The host IP in the host network is 192.168.56.1, ...
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0answers
236 views

Cisco ASA, Windows Server 08, PPTP/GRE issues

I am at the end of my rope on this one. I am trying to simply forward pptp/gre through a Cisco ASA to my Windows server. Here is what I have done: Access Rules: OUTSIDE ...
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1answer
3k views

How do I set a static IP for a virtualbox guest that has a network adapter configured for NAT?

I am running Ubuntu 12.04 as a VirtualBox guest, but I'm having trouble configuring a static IP. I have the network adapter configured for NAT, because I can't assign static IPs on my Universities ...
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1answer
40 views

Linux NATing on my own IP address

I have a question regarding Linux NAT-ing on my own IP address. Suppose I have a network interface, say eth0. It is given an IP address of 192.168.0.2. Now I apply a NAT rule in Linux saying that: ...
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0answers
377 views

Openstack seems to not map internal IPs to local network properly

I have a very confusing issue which I can't seem to resolve. I followed a guide by Loic Dachary on installing Openstack Folsom on Wheezy, and deployed it on two hosts: a cluster node, and my ...
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1answer
430 views

How can I access a server on local network using its public name?

I have a problem in which I cannot access a server using its public name from the same network as the server. Access to the server works fine from the internet. Reading up on this problem, I've ran ...
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1answer
389 views

Issue with Nginx, http authentication and dynamic IP address

I am trying to get Nginx as a reverse proxy to authenticate users performing inbound http requests. My ISP provides me with a dynamic IP. I am not sure how to configure my ADSL router (NAT rules). ...
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1answer
196 views

Can I improve speed in Hyper-V?

I use Windows Server 2008 R2 (it is host) with Hyper-V and a guest running Ubuntu 12.04 LTC. It is my settings: RAM 32768 Cores (virtual processes) 4. (I need 12) I also use virtual hard drive ...
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2answers
481 views

NAT Overloading not working, access-list not catching ips?

I have a GNS3 lab set up and I am trying to get NAT overloading working with a dynamic pool. Please see diagram The issue I am having is traffic is being routed correctly from PC1 to the ISP1 or ...
2
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2answers
461 views

Setting up NAT for multiple isolated networks with iptables

I have a gateway machine connected to multiple internal networks that I would like to set up NAT on. The catch, though, is that these networks need to be isolated from each other, which I haven't been ...
0
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1answer
103 views

Iptables & NAT retain original destination IP?

I've got a webfacing server that I've chopped up into guests, one of which is running apache with some pretty basic virtualhost config. I have redirection working, but my virtualhost config needs the ...
0
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1answer
405 views

ADSL Router - Access External IP internally

I have a problem when I'm doing an access using my DNS hosted at another server, which performs a redirect to my internal network. example: User attempting access to internal DNS: intranet.site.com: ...
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1answer
141 views

Forwarding ports from server with 2 internet connections

I have 3 interfaces on my main server, first is used for the local network, second and third are internet connections (each has its own ip routing table): eth0 192.168.0.1 eth1 9.9.9.9 eth2 7.7.7.7 ...
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3answers
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NAT Gateway - Maximum connection limit

I know just enough networking to be dangerous. The nitty gritty low level details of NAT are not something I am particularly knowledgeable about. I accidentally found myself in a discussion earlier ...
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4answers
2k views

Linux - two subnets, one interface, one gateway - NAT the additional subnet

We currently have a few servers that all use the same LAN: Host1: eth0 10.0.0.1/24 Host2: eth0 10.0.0.2/24 Host3: eth0 10.0.0.3/24 Gateway: 10.0.0.254 We want to run some VMs (VirtualBox) on these ...
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making a software router for my private network [duplicate]

give me suggestion on this problem. I have 2 nic cards public ip (eth1) and private ip (eth2). now i have a linux system having centos 6.4. I made this system software router so can access internet on ...
2
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3answers
3k views

iptables: combine SNAT with network remapping for OpenVPN

[Apologies for the long prelude; question halfway down.] I have a working OpenVPN setup whereby a VPN server pushes a route back to one client (hereafter called the “router”) which can then expose ...
0
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1answer
413 views

Change IP address of incoming packet with iptables

I have a server (S1) inside LAN, where a router is outside my control. On a server openvpn is installed and I can login with ssh to it. There is another server (S2) on the LAN, and I want to forward ...
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1answer
4k views

Do you need to enable ALG features in order to NAT H323 traffic on a Juniper firewall?

Can you NAT H323 traffic if ALG features are disabled (ultimately disabled H323 traffic inspection capabilities), or is that feature required in order to NAT such traffic?