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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Openvpn not routing to the internet over a tun interface

I've set up openvpn using tun. I can ping both ways between client & server. But I can't ping from the client to 8.8.4.4 (as a test). I've added nat with: iptables -t nat -A POSTROUTING -o eth0 ...
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2answers
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Exposing multiple virtual machines to public Internet from laptop on any connection

I've got a couple of Ubuntu virtual servers on my laptop that I drag around with me and use to test configuration and interaction of services like mail, directories, etc. I therefore want to make them ...
2
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1answer
855 views

vmware nat internet connection

Host: Windows Server 2008 / VMWare Server 2 Has Internet connection ip: 172.17.62.1 (NAT adapter) no gateway, no dns Guest: Windows Server 2003 ip: 172.17.62.2 (NAT) gateway 172.17.62.5 (set in ...
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1answer
469 views

Some HTTPS connections via NAT fail, but work on firewall itself

I am having trouble establishing some HTTPS connections from internal machines, even though these same connections work if initiated on the firewall itself. The firewall machine is running Ubuntu ...
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2answers
3k views

iptables nat: Handle OUTPUT chain via PREROUTING chain / forward from OUTPUT to PREROUTING

I would like to automatically handle packets in the OUTPUT chain of the NAT table (which are generated locally) like if they come from outside (via PREROUTING). Is is possible to use a "forward ...
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2answers
8k views

how can I access a webserver running on my NATed VMware Fusion guest from the rest of the subnet?

I am not allowed to run my VMWare guest in bridged mode, and I want to somehow tunnel from an agreed port on the Mac's external network interface to the webserver running on the VMWare fusion guest. ...
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1answer
2k views

Address (url) forwarding with Vyatta

Got this kind of noob question i suppose. I got this very basic network setup and need help to set up some address forwarding. As seen in my illustration below all traffic enters via the eth0 ...
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3answers
7k views

PPTP pass through on Cisco ASA 5505 (8.2)

Is it possible to setup PPTP VPN traffic (clients outside and server inside) to passthrough a Cisco ASA 5505 if the outside IP address is also being used for PAT? The Cisco examples forward all NAT ...
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1answer
576 views

NAT: Exposing SQL Server 2008 Express to the internet

I have a Windows Server 2003 SP2 machine with SQL Server 2008 Express installed. I have my network configured with a NAT. Internal clients can access the instance of SQL Server without a problem. I ...
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3answers
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Unable to ping or access internet

I am setting up a private network. The server is Windows 2008 R2 with DNS installed and has a fixed external IP address. ipconfig outputs the following: PPP adapter RAS (Dial In) Interface: ...
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1answer
3k views

Iptables and SNAT

I am a newbie to iptables with NAT. My network setup is as shown below linuxbox2 (192.x.y.a) | (194.160.1.1) | linuxbox1(eth1)-------- Switch ...
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2answers
880 views

SIP and NAT routers?

SIP was not built with NAT routers in mind, and I'd like to get to the bottom of this issue to check what needs to be done on all devices so it works with NAT routers, and understand in what context ...
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4answers
474 views

JUNOS firewall issues

I am in the process of trying to setup a Juniper SRX240. I have been using the screenOS firewalls for sometime and having some difficulty adjusting.I haven't quickly been able to find a way to do in ...
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2answers
1k views

How do you have NAT always assign the same IP address in VMWare Fusion?

I currently have 4 virtual machines I've created using out-of-the-box VMWare Fusion on my MacBook Pro. They are all configured with NAT for the networking and therefore get a 192.168.43.xxx IP ...
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2answers
99 views

Internet VPN Tunnel with a server behind NAT

Let's say someone would like to route all their traffic traffic though some PC in another country (to unblock some sites). However, this PC is a usual Windows 7 PC behind a router with NAT, which ...
2
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1answer
159 views

Redirection with natd flags on FreeBSD

I am trying to setup a basic NAT server. I want all traffic coming from the outside world to the NAT server to be redirected to another machine, where I have a lipcap service running to parse this ...
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0answers
112 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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1answer
314 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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1answer
79 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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149 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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0answers
98 views

Martian Source & Servers losing network

First off, I am pretty new at diagnosing network issues through linux. I have an intermittent problem with our LAN servers. They seem to lose all connection to the network and if I disable the adapter ...
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2answers
83 views

Special Routing and NAT requirement

I have a rather special routing and NAT issue which I hope I can fix somehow. Inside my company we run a supernet like 192.168.0.0/21 (192.168.0.1 - 192.168.7.254) All computers have this subnet mask, ...
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1answer
117 views

OpenVPN tunnel, iptables don't support NAT

I wanted to route my private PCs traffic through my VPS and set up my OpenVPN as fas as necessary but now I have the problem that I can't set iptables, since NAT support is disabled for my server's ...
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2answers
128 views

NAT, iptables and problematic ports

I am building a small office network with virtual machines. My schema is this: Computer A: gateway, ip 1.1.1.1, iptables used for NAT [eth0=public internet dhcp, dhcp; eth1=gateway] Computer B: ...
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272 views

NAT not working after enabling DirectAccess

following test setup is given: server1 - 1 network card connected to internal network (10.0.0.2/24) + gateway 10.0.0.1 server2 - 2 network cards (1. connected to internal network (10.0.0.1/24) / 2. ...
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159 views

Virtual guest doesn't NAT when using the hosts IP

I am using lxc to host some services. I wish to expose one of these services to the outside world. I have setup three NAT rules on my host using iptables, one for the eth0, one for br0 (the bridge ...
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239 views

How to configure opennebula for allowing a cluster private network to host images with public IPs

I am installing open nebula 3.4.1 for running virtual machines a (kvm based) cluster made of 5 computers: a front-end machine having 2 network interfaces and 4 slaves machines with a single network ...
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0answers
138 views

How can I specify which IP address is used for outbound traffic in OS X Lion Server with multiple WAN IPs?

I have a Mac Mini Server running OS X 10.7.4 (Lion). I am using the ethernet port for the LAN and I have a USB->Ethernet adapter for the WAN. I have assigned two external IPs to the USB->Ethernet ...
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2answers
869 views

Iptables: Forwarding packets doesn't work

I have 3 Linux Systems A, B and C. A is a TCP Client and sends a message to TCP Server on C. A can see only the external IP of B which is at wlan0 interface, 192.168.0.3 ------------------ ...
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0answers
507 views

Connectivity issues with dual NIC machine in EC2

I'm trying to get some servers set up in EC2 in a Virtual Private Cloud. To do this, I have two subnets: 10.0.42.0/24 - Public subnet 10.0.83.0/24 - Private subnet To bridge these two, I have a ...
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184 views

Two separate WAN uplinks for two different NAT networks

I have a server running ubuntu 10.04 with four interfaces. eth0 and eth1 have static WAN ip's, and eth2 and eth3 are connected to two separate NAT networks 192.168.0.0/24 and 192.168.1.0/24 ...
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2answers
333 views

is there any project that allows for NAT traversal for generic online guests?

Scenario: The basic goal is to allow "generic" online guests to be able access to some server behind a NAT. For example say I'm hosting some images on a server behind a NAT, I don't have admin ...
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2answers
496 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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0answers
729 views

Errror on connecting to VPN-server by Demand-dial interface (Windows Server 2008 R2)

I have several LAN-interfaces and internet access over VPN (connect to provider VPN-server). I want to setup NAT from local area networks to internet. For this I install on Windows Server 2008 R2 ...
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2answers
415 views

Linux, some packets are not being NAT

I'm trying to NAT HTTP traffic, I'm new to this and facing some issues. What I'm trying to do is NAT client HTTP requests to a webserver. CLIENT -> NAT BOX -> WEBSERVER When the client open the IP ...
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2answers
437 views

Bastion Firewall Host ipTables Redirect Question

Some background: A firewall has been constructed using RH Fedora 13, Kernel 2.6.34.7-63, and IPTables 1.4.7. The firewall is a simple, twin adapter configuration, with the external interface (eth0) ...
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3answers
2k views

Manual NAT on Checkpoint (Redirect all http requests to a local web server)

We have a proxy server in our internal network and I want to redirect all internet http requests to a web server in local network. It'll be like a Network Billboard that says "No direct connection is ...
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1answer
1k views

Why isn't ICMP routing with iptables nat routing

I'm using iptables on Ubuntu server to route a public IP to a private IP. I want to nat all traffic, including 80, 443 and ICMP. However, it appears that ICMP isn't routing. I have a steady ping ...
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1answer
153 views

NAT for static private addresses

Could someone please help me out with the following scenario: I have a machine that hosts 3 lxc containers, and acts like a router for them. The LXC containers have private ip addresses set on the ...
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1answer
4k views

What is strict, moderate and open NAT?

NAT options on domestic routers often come configured as strict. What does this mean? What do moderate or open do? Port-forwarding/DMZ access works properly on strict so why bother with the other two? ...
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How to properly nest a wireless router behind a wired router? [closed]

I wish to repurpose a wireless router to serve as a wireless access point behind a wired router (serving as gateway to WAN) so that I don't have to buy more hardware and recapture value on prior ...
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1answer
117 views

Accessing Remote Desktop on multiple windows machines behind NAT

Our company has multiple Windows servers running behind a NAT firewall. We would like to provide Remote Desktop access to these machines to our users. One of the solutions is by port forwarding. We ...
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5answers
1k views

Is it possible to detect clients behind a NAT?

Recently, UC Irvine's Residential Network department changed their security policies to include the following requirement: Reconfiguration of Home Routers Home routers will need to have DHCP ...
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3answers
446 views

iptables question

i have a small network, with one valid IP and a firewall with 3 network interfaces (LAN, WAN, DMZ). I want to enable PAT on this valid IP to redirect http traffic to a server in my DMZ. (done) I ...
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5answers
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How to cleanly and silently reload iptables rules?

I have very complicated and long iptables script. It is not possible to operate on the existing iptables configuration, by doing manual inserts/replaces or deletions. I have a script which simply ...
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Routing multiple static IPs from ISP at the cable modem?

I'm taking over IT responsibilities for a previous IT guy. We have a 50mb cable modem connection from Comcast along with 5 static IP addresses: XXX.XXX.XXX.180 XXX.XXX.XXX.181 XXX.XXX.XXX.182 ...
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1answer
191 views

Set up multiple servers behind a NAT

I am currently trying to set up a network with both a secure webserver and an internal openvpn server. The webserver is running windows 2008 and the vpn network is running the Access server from ...
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2answers
452 views

NAT: how client-server can work?

Let's say 2 user got 2 different ISP behind NAT. How MSN messenger can work if they are behind a nat? Thanks
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1answer
25k views

How do I configure port forwarding on a Watchguard XTM 2?

I have one external static IP that is nat'ed by the XTM to a local network, I would to be able to configure port forwarding on it (say external:80 -> 10.0.1.43:80 and external:2340 -> 10.0.1.48:2340). ...
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2k views

Windows Computers Joined to a Domain Behind NAT

If I have some Windows XP machines that are behind NAT, will all services still work as normal such as file sharing, printing, etc. The setup would be something like 192.168.20.0/24 NAT`ed to ...