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 VPC port forwarding on nat

I have 3 instances, one in a VPC private subnet, one NAT instance, and another outside the VPC, which acts as the web server. The instance in the private subnet acts as an app server and the ...
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147 views

Asterisk behind Cisco ASA 5505

I'm in the process of upgrading from an old WRT54GL running Tomato to a Cisco ASA 5505, versioning as follows: Cisco Adaptive Security Appliance Software Version 9.1(5)21 Device Manager Version ...
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43 views

Route new outbound traffic

I am looking for some iptables rules which can help me to route some traffic from a server : Client 1 ----| Client 2 ----| |----------| Client N ----| ssh, ...
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35 views

IP forwading amazon ec2 another server IP

I use this command in windows azure (NAT), to redirect all requests to another server with other IP iptables -t nat -A PREROUTING -i eth0 -d 10.240.154.15 -j DNAT --to-destination 192.188.47.63 ¿ ...
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794 views

How to forward ports to DMZ using iptables and separate modem

I have a network that looks like this: ADSL VLAN 2 VLAN 3 ------[Modem]----------[firewall]----------[intranet PC] | | ...
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290 views

Access Apache VirtualHost from localhost

I have a DirectAdmin setup with Apache on a server which is behind NAT. Everything is working correctly when accessing a VirtualHost from outside the machine (either through the Internet and the ...
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491 views

Redirect traffic on port 80 into apache for unknown macs, and into squid for some macs

I have a linux box behaving like a router that handles two network interfaces: eth0 for internet and eth1 for LAN. I set up iptables in order to redirect all the web traffic coming by the LAN into a ...
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498 views

iptables can drop traffic but cannot redirect

Suppose that TCP packets are sent to destination ip (dest_ip) and can be dropped by the following command: iptables -A INPUT -d dest_ip -p tcp -j DROP But when I try to redirect the packet using ...
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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 ...
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436 views

Passive FTP that would work inside and outside of NAT

I'm using vsftpd 2.2.2 behind the NAT. To make it work, I set pasv_address to my external (internet) IP. Now the problem is with clients that connect it through the LAN - they try to connect to the ...
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375 views

Setting up IP masquerading by passing packets through external nodes

I'm trying to find a solution to prevent remote machines determining the source IP of my webserver. This is to hide the webserver's actual IP, helping avoid DDoS attacks. Incoming requests are ...
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599 views

Connect KVM virtual network to internet

I have a CentOS server running KVM and need to connect a virtual network to the internet. The network must be routed or NATted, it must not be bridged (port security). If possible, I would like to ...
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705 views

Virtual box linux routing

Sorry for the basic question but I cant figure this one out. I want to set up a small network of linux servers for testing purposes. So I have a host server running virtual box with the following ...
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235 views

Linux ( Fedora 15 ) multiple ISP and NAT routing

So I have my system running Fedora 15 and currently with a DSL line. The line provides a static IP along with static route, DNS. I run a web/E-Mail/DNS server from this IP. It also supports a NAT'd ...
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587 views

pfsense firewall filter rules behind nat?

i am new in pfsense i have vmware which pfsense and windows xp are installed on them pfsense in using ip 192.168.44.1 for LAN and 192.168.121.129 for wan (which is NAT) my win xp ip is 192.168.44.2 ...
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314 views

port forwarding to access services on servers behind NAT

I have some security camera systems in different locations, each location does have internet, the ISP is NATing all the IPs so theres no way to open ports to my systems. My solution was to rent a VPS ...
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319 views

NAT and ISP Subnet when load balancing on pfsense?

I have a pfsense box that I'm trying to plan the configuration for. I am going to be load balancing two ISP's, each with their own /29 static IP subnet. The question I have is in relation to the way ...
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85 views

NAT ports - how do they work?

I have the following network schema: Computer A: three nics: NIC 1 (eth0): dhcp, public internet NIC 2 (eth1): static 192.168.1.1, gateway for Computer B NIC 3 (eth2): static 192.168.2.1, gateway ...
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102 views

ASA permit only one host to *.xyz.com

I want to allow a host to download some updates from *.xyz.com (in internet). How should I permit only this host from my inside network to access *.xyz.com on ASA, access can be via http? At moment ...
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543 views

iptables and virtual machines of KVM, no ping, no ssh from VMs

Hi everyone :) I have two virtual machines KVM. I did two alias to eth0 - eth0:0 and eth0:1 and put them on an external IPs (eth0:0 - 89.114.122.3, eth0:1 - 89.114.122.4)​​. Now the problem is: ...
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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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458 views

iproute and nat across devices

I've got the following configuration: vlan123@eth0 - range 1.2.3.0/24, with 1.2.3.4 assigned to it br2000 - range 10.2.3.0/24 In the ip route I see: 10.2.3.0/24 dev br2000 proto kernel scope link ...
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389 views

NFS proxy / re-export

I have a situation where I need to mount a few NFS shares on a series of clients on replicated VM networks. So their source IP addresses are not unique. In between the client and the server there is a ...
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945 views

Reverse NAT Setup for Hyper-V on Win 2008 R2

I'm trying to setup a Linux server behind a Windows Hyper-V host that will help supply some of the services (SSH, HTTPS, etc). However getting RRAS configured for reverse NAT (port forwarding) turned ...
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406 views

Inbound connections using Internet Connection Sharing in Apple/Mac/Leopard

I have a Mac mini which I'm using to give some other devices wireless access, by sharing it's Airport connection with the local ethernet, and that is plugged into a switch. All devices can get online ...
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167 views

Load balancing + NAT issue on BNT GBE 2-7 gear

I've got troubles configuring an Hardware load-Balancer with NAT functions. I have the following architecture: Internet ===> VIP (public) LB (private ip) ====> private addressed servers When a ...
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321 views

If I suspend and resume my vmware host vista box, I have to restart the VMware NAT service or my guest Linux DNS requests won't resolve

If I suspend and resume my VMware host (Workstation 6.5) Vista box, I have to manually restart the VMware NAT service or my guest Linux (Ubuntu) DNS requests won't resolve. I can ping boxes on the ...
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25 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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15 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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17 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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45 views

Is my gateway a fixed or a dynamic IP?

I have some virtual machines under my control with Azure, some of them have public IP and some of them don't. In regards to the one that don't: I can see that they still have internet outbound (not ...
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85 views

Connecting to an AWS RDS behind a NAT with an SSH tunnel

I've set up a MYSQL RDS on AWS, in a private VPC behind a NAT. With Workbench, I can connect successfully from a remote client into the RDS no problems - so all of the RDS, the NAT and the security ...
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47 views

Forwarding IPs to Switch for NAT

I have a Question. We actually have a Cisco 1812 Router and we're Switching to an ASA 5512-X. The Problem is, the ASA 5512-X only has 6 Ports. The 1812, had 8. All in use. We need to translate 3 ...
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125 views

Watchguard, accessing server with public IP from internal network

I can't go trough it. I need access from my internal network to a server with public IP. I have private network with few VLANs, and then I'm using Watchguard m400 firewall. The server, that I want to ...
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114 views

How to mapping ports from a single public IP to multiple internal servers in Fortigate Firewall?

I have one public IP and I want to use it for 3 servers behind Fortigate Firewall, two for RDP and one for Mail server. I can NAT one public ip to one private local ip but I can not NAT to Multiple ...
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77 views

When I ping local IP address I get a reply from external IP

I have SonicWall NSA 2400. Port X2 is WAN port with following settings X.X.X.250 / 255.255.255.248. I connected VPN concentrator to port X5, which is assigned to DMZ zone in Transporarent IP Mode for ...
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78 views

Assign WAN IP on internal NAT network

I have a static WAN IP address (in the example 77.88.99.166) that is provided by a DSL modem that also has a static IP address (77.88.99.165). The modem interfaces with a firewall/NAT router (green) ...
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90 views

Amazon Linux - iptables NAT rules not matching GRE traffic

I'm trying to prototype something in AWS VPC/EC2, but I can't get my NAT rules to work. I have the following setup (all instances running the Amazon Linux AMI): GRE Tunnel between instances ...
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59 views

VoIP: No audio, local IP in SIP header

I'm trying to get SIP trunking to work on my Bintec Elmeg hybird 130j with sipgate.de as trunking Provider. So far, call signalisation works fine, so I can call outside phones and also get called ...
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38 views

Azure NAT blocking connections

When I try to connect to a port on the public IP address of a node, 50% of the time Azure doesn't respond and nmap marks it as "filtered". When I try to connect to the same port from the node using ...
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71 views

Cannot SSH to ec2 instance in VPC

I'm just starting with AWS, and have 2 ec2 instances running on a VPC, one with a public and private IP, one with only a private IP. I can SSH to both (using my key) if I attach an external IP to ...
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23 views

public tunnel into private behind-nat machine

Say I have a web server running on my local machine which is connected to the internet but behind NAT (let's just assume it cannot be reached directly from the outside but It can open TCP/UDP ...
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213 views

How can I do site-to-site OpenVPN routing without NAT

I have two OpenVPN servers at different location. Each machine in one location can ping and connect to every machine in the other location. My problem is when I use SSH to connect from machine A in ...
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1answer
56 views

Hyper V and NAT Redirect IP on different VM

I have 2 IPs public (but one physical network port) and i want redirect IP public 1 on my VM 1 and, IP public 2 on my VM 2 But when i check my NAT configuration i can just redirect port on my interne ...
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341 views

CISCO - organize NAT with 2 WANs, 2VLANs and failover (using PBR / ip SLA )?

We have a CISCO 800 series connected to 2 WAN channels, and 2 VLANs. The idea is to have VLAN1 always use WAN1 channel, and VLAN2 use WAN2 channel, but in case of connectivity failure switch to a ...
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55 views

NAT forwarding (whole IP) working only on some ports

Since my hoster doesn't allow briged setups I had to go for a NAT solution to run my CentOS VM on an additional IP and my host machine on the primary IP. Now, I've got a problem since for ports 22, ...
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71 views

Determine internal(LAN) IP address based on external connection port

We have an external VPN server; somebody within the LAN has connected to it, and I can see the port they connected through (ie. the NAT port the router set up for them). Is there any way to find the ...
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113 views

route output traffic from specific NAT'ed VM via ip alias

In a dedicated server with several containers behind NAT, I'm trying to route the output / outbound traffic from one of the containers through a specific virtual interface attached to the main ...
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325 views

Route traffic through private IP for only certain hosts - CentOS 6.6

I am having a weird problem which I cant figure out - so I was hoping someone here could give me a hand. First off the end goal is that a specific server in my network runs an IPSEC connection to ...
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889 views

Cisco IOS, Multiple WAN & Port Forwards (Outside -> Inside PAT)

I have been trying to work out how to accomplish PATing from Outside to Inside on a Cisco IOS router, in this case specifically a Cisco 2901 running IOS Version 15.1(4)M1. Firstly, the problem I am ...