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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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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0answers
18 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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1answer
24 views

Need help configuring NAT

First of all, the router I am using is a Cisco WRVS4400N. My company runs a software which handles the MySQL database of all of their products. The software now has an e-commerce module, so I have ...
0
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0answers
7 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 ...
0
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1answer
18 views

Iptables and counters

I'm trying to use iptables counters with munin to monitor traffic of hosts on my local subnet. For each host I set up a rule like this: iptables -I OUTPUT -d $ip This should count the packets going ...
0
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1answer
21 views

Configure clients to navigate through specific wan. Pfsense

I have a machine with a pfsense running. It is configured with three ethernet cards. LAN 192.168.2.1/21 WAN1 200.41.X.2/24 WAN2 200.41.X.3/24 ISP Gateway 200.41.X.1 This is a connection with 5 ...
2
votes
1answer
71 views

What is the correct iptables rule when NATing multiple private subnets?

I have a Centos minimal 6.5 acting as a router. eth0 is connected to a Cisco switch trunk port, allowing VLANs 200-213. I have several VLAN interfaces just as this link suggests: ...
2
votes
1answer
282 views

How to Configure Source NAT (Private IP => Public IP Outbound)

I'm running VMWare ESXi Free and have Zentyal SBS 3.2 running as a Gateway. I have 5 Public IPS (CIDR/29, let's call them 69.1.1.1 - 69.1.1.5) and currently Zentyal is bound to 69.1.1.1 as the ...
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2answers
367 views

IPTables: NAT multiple IPs to one public IP

I'm looking for a way how to nat 2 or more inner IPs (in my case xen doms) to one outer IP. I tried to use iptables -t nat -A PREROUTING -d 123.123.123.123 -j DNAT --to 1.2.3.4 --to 1.2.3.7 ...
2
votes
1answer
77 views

Proxmox Nat Networking Issue

Definition I have installed Proxmox 3.2 and i am trying to configure a virtual machine as a communication server that handles all traffic and forwards them to the nodes with private ip. I ...
0
votes
1answer
739 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 ...
2
votes
2answers
922 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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votes
1answer
56 views

One Public IP, Private IPs, DNS Server and Multiple Servers [closed]

I have lots of unanswered questions about these topics. So, lets begin. First off all, I'm not a server and networking guru. I'm a regular PHP developer. And I've read allmost all of the articles ...
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2answers
2k views

Cisco ASA - Configure External Access to a Server

I'm trying to configure my ASA (ASA 8.4(2), ASDM 6.4(5) ) to allow external access to a server (using RDP). I've tried everything, but it doesn't seem to be working. I'm sure it is something simple ...
0
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0answers
20 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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3answers
944 views

Forward traffic to local LAN IP while keeping the originator IP

I am trying to forward traffic from one server to another, while keeping the origin requestor IP. Therefor I cannot use SNAT or MASQUERADE. SERVER A: Public IP: 111.111.111.111 Private IP: 10.0.0.1 ...
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1answer
24 views

Cisco ASA Outside to Outside NAT (forward from one public ip to another public IP)

I have an ASA (A) with a set of public IPs (A1..A6). And I have another server S with a public IP (S1) . I want all traffic to A2:22 NATed (forwarded) to S1:22. (SSH is just an example here) If ...
5
votes
3answers
8k views

Public static ip for vagrant box

I have server (Debian Squeeze) with 1 ethernet card and 2 public static IPs (188.120.245.4 and 188.120.244.5). What I want: Setup virtual box (Ubuntu) with access via static IP (188.120.244.5). ...
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0answers
17 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 ...
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1answer
860 views

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 ...
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votes
1answer
25 views

iptables: disable NAT except for only one client

I have a LTSP subnet (192.168.0.0/24) and want to disable NAT for every client except one client The purpose is to deny (on demand) access to internet from student clients, but always allow it from ...
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0answers
31 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 ...
2
votes
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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2answers
30 views

Iptables does not seem to be applying SNAT to packets sent on a raw socket

I'm sending packets from a user space program to my wireless interface wlan0. I've set up a SNAT rule with iptables as follows iptables -t nat -A POSTROUTING -o wlan0 -j SNAT --to 192.168.1.3 And ...
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votes
1answer
33 views

Automatic updates for NAT instances and SSH connections in a AWS VPC with private subnets

My current website architecture has two Ubuntu servers with public IPs in Rackspace Cloud. One of them is web and mysql server. The other one is for time-consuming calculations only. Both of them ...
0
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2answers
760 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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0answers
431 views

Puppet agent (v3.0.1) hangs connecting to master (v3.1.1) in VM behind firewall (with NAT based access)

I am using puppet agent v3.0.1 (On FreeBSD), trying to connect to a puppet master v3.1.1 (On Ubuntu) and the puppet agent hangs with the following debug output: puppet agent --debug --no-daemonize ...
4
votes
1answer
715 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 ...
0
votes
1answer
933 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 ...
3
votes
2answers
478 views

Symmetric NAT and UDP Hole Punching

I've read this question, but the explanation of Symmetric NAT wasn't detailed enough. Please could someone help me to understand the following paragraphs? I read this about Symmetric NAT: Each ...
2
votes
1answer
47 views

pfSense Cluster not working with Manual NAT

I have two pfSense clusters, one is 2.1.4 and one is 2.1.3. The directions suggest that Manual Outbound NAT is required, but the 2.1.3 cluster is working just fine using Automatic NAT, servers and ...
3
votes
2answers
9k views

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

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. ...
0
votes
0answers
17 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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votes
0answers
26 views

Load balancing Bind9 with Keepalived and LVS

How can I correctly configure LVS to masqerade/NAT packets from virtual ip to/from clients? Currently I have: UDP 10.47.1.80:domain rr -> 10.47.1.51:domain Masq 10 0 ...
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0answers
85 views

Route two public (ISP assigned) subnets on 'outside' interface of Cisco ASA 5510

We've got a Cisco ASA 5510 that sits on our edge and acts as the PPPoE endpoint for a fibre connection. The fibre connection came with a static IP, which is assigned via PPPoE, and gets picked up by ...
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0answers
32 views

VPN routed traffic, response goes outside of VPN?

Here's a weird one. Whenever I'm on a hotel network I tend to like to route all my traffic through my home network. Mainly since I'm not entirely sure all my passwords go through SSL all the time. ...
3
votes
3answers
13k views

Passive mode for FileZilla FTP isn't working

We have FileZilla server 0.9.37 running on Windows server 2008 R2 Active mode works OK, The Windows firewall on the server is off. Our Router is a DrayTek vigor 2820. Under NAT, Open Ports, I have ...
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votes
3answers
3k views

Does NAT change the source MAC address? [closed]

I'm trying to secure my home network but don't really need the complexity of a VPN so I'm trying to figure out other options. I'd like to allow my iPhone remote access to my home servers but I can't ...
5
votes
3answers
2k views

iptables nat does not exist

Today my iptables nat on the host system stopped working and I have no clue what happend! (That's very bad, I know) All commands are executed as root user. If I run $ iptables -t nat -L I get the ...
0
votes
0answers
47 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 ...
9
votes
7answers
4k views

Loopback to forwarded Public IP address from local network - Hairpin NAT

This is a Canonical Question about Hairpin NAT (Loopback NAT). The generic form of this question is: We have a network with clients, a server, and a NAT Router. There is port forwarding on the ...
0
votes
0answers
30 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 ...
0
votes
0answers
58 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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votes
0answers
36 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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votes
1answer
836 views

How to access server using public ip when in the network itself? [duplicate]

I've asked this question and even searched around but didn't get a useful answer for me. Basically what im doing is i have a webserver on internal ip 192.168.0.100 port 80. So if im in the network it ...
0
votes
3answers
121 views

Do I need public DNS records for the external IPs of our workstation NAT?

We have certain stakeholders who believe that the public IPs used by our workstations should have globally available DNS records, and that not having dns records would break some internet services. ...
7
votes
2answers
205 views

FreeBSD's ng_nat stopping pass the packets periodically

I have FreeBSD router: #uname 9.1-STABLE FreeBSD 9.1-STABLE #0: Fri Jan 18 16:20:47 YEKT 2013 It's a powerful computer with a lot of memory #top -S last pid: 45076; load averages: 1.54, 1.46, ...
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2answers
86 views

Windows Server 2012 NAT Routing won't route clients from subnet (multiple external ips)

I obviously have some knowledge gaps in routing maybe you can help me: My ISP has given me 8 external IPs but I have to route them myself. The first IP is issued via DHCP and the other 7 are fixed. ...
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1answer
379 views

Does hole punching require a UDP rendezvous server Or could it be a TCP one?

I'm trying to get my head wrap around this issue... I would like to connect two users... Those users are already connected to a TCP server, which is aware of both public ip and connection TCP port. ...
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votes
1answer
62 views

can anyone show me how can i fix error with my NAT config

Can anyone help me with my packet tracer problem? My network 2 buildings (each building has 3 vlans) on the same side and it has 2 sides, between is internet. I finish with DHCP and now I try to ...