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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796 views

Windows Server 2003 IPSec Tunnel Connected, But Not Working (Possibly NAT/RRAS Related)

Configuration I have setup a "raw" IPSec tunnel between a Windows Server 2003 (SBS) machine and a Netgear FVG318 according to the instructions in Microsoft KB816514. The configuration is as follows ...
4
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1answer
256 views

Multi homed firewall with ipnat

i am trying (without success) to configure a ipnat/ipf box under FreeBSD 8.2, here is the scenario: outside inside +----+ ADSL ...
3
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1answer
45 views

Reaching out DHCP relayed hosts

I have one primary server (DHCP) and one secondary (DHCP-RELAY). Majority of hosts are served from primary (wirelessly), however there are a few (wired ones) which get their IPs from secondary. ...
2
votes
1answer
177 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 ...
2
votes
1answer
121 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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173 views

Debian forward through NAT EOIP GRE

eth0 = WAN eth1 = LAN to forward any port through nat I use e.g: iptables -t nat -A PREROUTING -p tcp -d 79.188.31.34 --dport 8291 -j DNAT --to-destination 192.168.0.36:8291 and it works, but ...
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202 views

Linux router with multiple gateways and port forwarding

I want to use a Linux VM to act as several routers at once. I have multiple servers hosting different services and dedicated public IP for each of them. Super simplified setup example: Ubuntu ...
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0answers
79 views

Should a NAT host be separate from a Bastion host

Have a private network with servers that required SSH access. Since the instances are in a private subnet, they cannot be accessed directly via SSH and require a public Bastion host to access. ...
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78 views

tun0 not listening traffic on a simple vpn example

I tried to setup a simple vpn test server on Ubuntu 12.04, called ToyVPNServer. The guide is simple and I take test for days but still cannot get connected. The inspection result is showing the issue ...
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59 views

SRP521W Intervlan routing and NAT

I've a Cisco SRP521W router which I've set up with two VLANs called normal_Lan and SWSVLAN. I don't want devices on each VLAN to communicate with each other so I've turned INTERVLAN Routing OFF. ...
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200 views

Cisco 2901 Inbound NAT with local IP overload

Overview We are replacing a Juniper SSG on one of our networks with a Cisco 2901. Everything has so far been quite smooth except some issues have come up with external ports needing to be opened. ...
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224 views

Remote client (android) can't connect to OpenVPN sever behind LAN

My plan is to connect over tunnel (via Internet) android phone with my LAN at home. I set up OpenVPN server behind (router) lan (ip adress is 192.168.1.3). There is also my laptop. Port 1194 UDP on my ...
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56 views

NAT with port forwarding on same interface

I have some issues with the port forwarding on same interface. I have server1 with the public IP 5.1.1.1 and one company publish a MySQL database with IP 10.1.1.1 through VPN reached only by server1. ...
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101 views

How to use linux repository for setup (ubuntu) when box are in aws scenario 2 wizard created private subnet?

I know lots of questions and I have personally tried manual VPC creation multiple times until I gave to the wizard (NAT concept wouldn't stick). I thought the wizard would actually configure ...
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126 views

NAT Traffic via my instance in Microsoft Azure

I'm working in Azure IaaS Environment I have a private network 172.16.0.0/16 in which I have few linux instances running (172.16.0.1-5) My instances are accessing the public internet on port 80 (so my ...
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200 views

How can I allow NAT from inside to outside and vise-versa when each of my clients will have only one static public IP using an ASA5525-X?

My network topology is pretty basic. My data center provides a router and added a switch just before my cage to provide connectivity to all of the racks. My rack takes the copper drop they provide and ...
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0answers
50 views

Cisco ASA5505 Public IP Address

I am trying to configure a Cisco ASA5505. I am using the GUI start up wizard. When I assign the outside IP address to be a public IP address the configuration will work but after about 30 seconds the ...
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60 views

How to fix stalled connection on large download

I have a cisco 1921 router performing routing and NAT function. Cisco 3750 is performing layer 3 core switching duties. Users are complaining about large file transfers being stalled (not dropped) ...
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230 views

puppetlabs/firewall nat policy issue

I'm using puppetlabs/firewall. I need to create following iptable rules: iptables -A PREROUTING -p tcp -m tcp --dport 443 -j REDIRECT --to-ports 8443 My manifests is firewall { '001 default ...
0
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0answers
146 views

Cisco ASA 5505 Access Rules/NAT

I need to allow traffic from any IP to a specific port in an ASA 5505 using ASDM 7.1. I've already created an Access Rule to do this but I ran a Packet Tracer and it gets dropped due to an "implicit ...
0
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29 views

NAT with multiple connections

I have a linux server with 2 WAN connections. It has 2 public IP address as WAN_IP1 and WAN_IP2. The server default gateway is WAN_IP1. The server also has 2 LAN interfaces and the relative subnets. ...
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139 views

Cisco ASA 8.2, accessing an internal webserver with an external IP-address together with port translation

We have one web server, let's call it SERVER01. It is running two different web servers that both uses HTTPS, INTERNALAPP on port 443 and EXTERNALAPP on port 444. In a previous setup we had an old ...
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votes
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188 views

unicast to multicast using Mikrotik

I'm looking for a way to do NAT on a mikrotik router so that a unicast stream received on one interface goes out another interface as Multicast. I've done this on Cisco before, but my company is ...
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131 views

ISC DHCP Server - Client Uplink Is Not Working

Running a DHCP server, client(s) does not have up-link (0Mbps) and has a downlink (50Mbps.) I am setting up a gateway/router on a PC running Debian Wheezy with ISC-DHCP. I have 1 WAN (eth0) and 2 LAN ...
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161 views

iptables on router: why does nat prerouting not intercept packets?

There is a Debian Wheezy box with OpenVZ kernel (IP 1.1.1.1), working as router between Internet and VPS'es (IPs 1.1.1.100 and 1.1.1.200). Incoming packets addressed directly to VPS'es are normally ...
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448 views

Packets are not routed by iptables, how to debug

I'm using OpenStack and OVS. This is my case: From a remote host, I ping VM with IP A. Local gateway received the echo request, then send a packet with IP A and MAC address A' (based on a fixed ...
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84 views

Simple MASQUERADE NAT between 2 VM

I'm on a cloud service and I'm trying to set up NAT between two VM. I've never experienced issues in this simple step, but this time is different and I'm near to give up. The first VM had two ...
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votes
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279 views

Cisco ASA 5505: PAT / NAT between 2 IPSec Tunnels

I've the following Setup: Customer <-> HQ <-> Branchoffice The Customer has a 192.168.1.0/24 subnet. On the HQ only the VPN Gateway is in my context, 172.20.10.1 . And on the Branchoffice ...
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152 views

Linux routing: How to allow a device inside private network to connect a public IP over an unknown network?

Consider following network topology: ---------- ---- (my network) ---- | Device 1 | (.101) | 192.168.191.0/24 | ---------- | | ...
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167 views

KVM : domain names are resolved, but cannot ping

I've found that in KVM, my networking is acting funny. Oddly (1) I can resolve external internet locations using nslookup or ping , but I cannot actually receive a ping back. (2) I cannot ping ...
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95 views

Listening “through” GRE Tunnel

Currently I'm looking to learn about using GRE Tunnels and I have the following scheme: Server1 (200.1.2.3) ----> Server2 (190.1.2.3) Both servers have public IPs Then I've setup a GRE Tunnel with ...
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513 views

Port Forwarding to a VPN Client

I'm looking for some help getting a port forward setup to a VM running Ubuntu 12.04 on my LAN. I can forward the port to the VM successfully and connect to the service over the Internet. But when I ...
0
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0answers
83 views

NAT answers instead of remote host

Currently I have VPN client access set up on OpenSuSE 13.1 server to third-party remote Cisco VPN IPSec server. VPN Server is set up to provide access for a host only and to provide access for a local ...
0
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683 views

pfSense NAT routing using VLANs

We already have pfSense installed and it is working for our single IP address on 1.1.1.1. We also have a further 3 ip addresses (1.1.1.2, 1.1.1.3, 1.1.1.4) which are set up as VLANs on the WAN ...
0
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0answers
202 views

FreeBSD ipnat(8) rdr - not redirecting

I'm using FreeBSD-10.0-RELEASE: root@fx:~ # uname -a FreeBSD fx.alexus.org 10.0-RELEASE FreeBSD 10.0-RELEASE #0 r260789: Thu Jan 16 22:34:59 UTC 2014 ...
0
votes
0answers
219 views

Load-balancing PPTP connections

I'm trying to load balance two PPTP connections, connected to the same server. I use the following script, but there is no send and receive via PPTP connections. What part am I doing wrong? Are there ...
0
votes
0answers
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 ...
0
votes
0answers
553 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 ...
0
votes
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 ...
0
votes
0answers
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 ...
0
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214 views

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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386 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, ...
0
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0answers
235 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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345 views

Are my NAT rules in ASA 8.6 correct

I am working on converting some PIX rules to ASA 8.6 syntax. Do the following achieve the goal? Assumptions: outside's IP address is 66.66.66.5/29 The outside IP address I want things translated ...
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119 views

Routing static IPs

This is probably a simple question for you experts. I have a BT infinity business broadband account, that offers 5 static IP addresses. I'm trying to expose a server on one of those addresses. This ...
0
votes
0answers
1k views

Cisco 1921 - Using NAT (NVI method) between VRF's slow performance

I'm setting up a Cisco 1921 with two VRF's: one to the internet and one to the LAN. The LAN is in private address space so source address translation needs to happen when the packets leave the ...
0
votes
0answers
121 views

Why NATted packets have different source ip addresses?

I've got ubuntu box with nat. Here is the problem: root@office.redhelper.ru:~# tcpdump -i tap0 host 194.190.8.141 -n tcpdump: verbose output suppressed, use -v or -vv for full protocol decode ...
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votes
0answers
219 views

set DMZ server on modem that not support DMZ, using port forwarding

I have to see an application server from outside of my network, but the modem that I am using is a Zyxel P-660-HN-T1H that not supports DMZ server configuration.So, which port(s) I should forward to ...
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172 views

Multihoming, NAT and ICMP

My router is the default gateway of a LAN and is multihomed. ISP2 is used for HTTP, HTTPS and ISP1, the default gateway of the default routing table, for the rest of the traffic. Similar questions ...
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How to setup NAT to work with ESXi 6.0?

Edit - To cut a long story short, we assume that it is not possible to use vsphere with only a single subnet and DHCP range. We would need to purchase a router to create a second network. We have the ...