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.

learn more… | top users | synonyms

0
votes
1answer
109 views

Keep source port for outgoing packets

I have 2 interfaces eth0(192.168.0.1) and eth1(10.1.1.15). And I do nat for all packets in this way. iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -j MASQUERADE Now I want to keep source port ...
0
votes
1answer
319 views

Proxmox with iptables nat is not available

I got an issue with iptables on my virtual machines. I installed proxmox 3.1-21 on my rootserver. I have around 6 IPs linked to my rootserver so i created new 'CT's. The problem is i need to ...
0
votes
0answers
264 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 ...
2
votes
0answers
191 views

Apache Instance in Private Subnet not returning packets

How can we get the Apache instance in a private subnet to work? Configuration Public subnet with 1 NAT instance Private subnet with 1 App instance Details 1. Masquerading is turned on NAT on via ...
1
vote
0answers
176 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. ...
0
votes
2answers
1k views

Using Router with DHCP and NAT and Windows Server 2012 as DNS

I have a network currently set up as per the image below. We use Regus's shared Internet and I've create a sub network for our office by using DHCP and NAT on the airport extreme router. Now the ...
0
votes
1answer
2k views

Port forwarding with iptables -> connection refused

I am trying to redirect requests to my local IP (10.42.42.152) on port 80 to a remote server, e.g. google.com (173.194.113.104:80). The remote server is up, ip_forward is enabled but I only get ...
2
votes
1answer
264 views

Stateless NAT with CentOS 6

I'm looking to set up the following: ---[IVR 1] | (internet)----[CentOS box]---+---[IVR 2] | ...
0
votes
0answers
298 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 ...
0
votes
0answers
78 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. ...
0
votes
0answers
125 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 ...
-3
votes
1answer
67 views

What happens if all the ports of router(doing NAT) are occupied ? [closed]

Suppose n computer are connected to a router R .It is doing NAT but suddenly all of its ports are occupied .So when a new computer N tries to connect what would router do means it simple do not ...
0
votes
2answers
170 views

Connecting to OpenVZ Container that uses NAT

lets say i do not have enough IPs to allocate to each container, how would someone connect that container if it has no public address? (using NAT for that container) the address would be private ...
1
vote
1answer
142 views

It it safe to forward an ephemeral port to an internal host in a NAT environment?

Short story, I want to expose SSH from a box in a NATed environment to the internet but would prefer to do it on a high (in the ephemeral range) port. Is it safe to port forward an ephemeral port to ...
2
votes
3answers
4k views

Is it possible to configure a reverse VPN tunnel?

Basically, my goal is to have a 100% portable and independent server. I'm building it using a Raspberry Pi powered by solar panels and batteries, and it is to be connected to the internet using a 4g ...
0
votes
1answer
63 views

Port forwarding with 2 interfaces not working

I'm running debian and I've got the following network configuration: eth0 Link encap:Ethernet inet addr:192.168.16.6 Bcast:192.168.16.255 Mask:255.255.255.0 inet6 addr: ...
0
votes
1answer
216 views

IPsec VPN Site-to-Site: Unable to reach hosts on same subnet as gateway

I am trying to bridge an office network with an Amazon VPC cloud network. So far everything seems to be working, except that I cannot reach servers on the same subnet as the cloud gateway. Office ...
0
votes
2answers
140 views

use iptables's nat to proxy mysql

I find this similar thread but don't work: http://stackoverflow.com/questions/10864854/forwarding-mysql-connection-with-iptables-and-differents-network-interfaces?rq=1 My environment as follows: ...
0
votes
2answers
330 views

NAT Masquerade to a L2TP/IPSec connection

I'm trying to create two networks (using a debian server) : The first one is intended to pass packets in a normal way (to my ISP). The second one is intended to pass packets via a L2TP/IPSec VPN ...
-1
votes
1answer
28 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
votes
1answer
87 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 ...
-1
votes
1answer
1k 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
331 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
435 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 ...
0
votes
1answer
844 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 ...
0
votes
0answers
362 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
votes
1answer
121 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 ...
3
votes
1answer
3k 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 ...
2
votes
2answers
389 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 ...
0
votes
1answer
244 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 ...
2
votes
1answer
386 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 ...
0
votes
1answer
479 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 ...
1
vote
0answers
749 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 ...
0
votes
1answer
112 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. ...
1
vote
2answers
216 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. ...
0
votes
2answers
2k 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. ...
-1
votes
1answer
113 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 ...
2
votes
0answers
86 views

Change sender-IP for VM in libvirt behind NAT

I have a server with my own public /28 IPv4 Network. On this server I have some vServers, done with KVM/libvirt. These vServers are connected with a virtual network, NATed to the internet. Every ...
0
votes
0answers
770 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 ...
0
votes
0answers
110 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 ...
0
votes
1answer
4k views

Can't establish a reliable VPN tunnel (ShrewSoft client / ZyWALL USG-50 firewall)

I try to setup an IPSec VPN tunnel through my firewall (ZyWall USG-50), but it doesn't work like it should. quick scheme of my installation: ME [A.B.C.D] --- **INTERNET** | ...
0
votes
3answers
387 views

Packages drop when using iptables NAT

We are using NAT made with iptables. However when there are lots of connections (or sessions) through NAT server packages start to drop. There is no log in syslog etc. I think this is caused by sysctl ...
0
votes
2answers
33 views

Does it seem from NAT when they really come through a proxy?

Just question. When a client really come through a proxy, can we tell it from being through NAT?
2
votes
1answer
6k 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 ...
1
vote
2answers
186 views

Assign internal IP address based on subdomain

I have a domain name, let's say foo.com. I have a server which has a public IP (Server-A). I also have a lot of servers (Server-B, Server-C, Server-D etc) which are all connected in a private network ...
0
votes
0answers
354 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 ...
0
votes
0answers
226 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 | ---------- | | ...
0
votes
1answer
7k views

Port Forwarding on Cisco Router

I'm a Cisco newbie, have the 1841, with two ethernet interfaces: interface FastEthernet0/0: Internal Desired destination IP: 186.67.181.140 interface FastEthernet0/1: External World IP ...
0
votes
0answers
215 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 ...
0
votes
1answer
98 views

ifconfig TX/RX on gateway

I have a linux gateway which does nat for a couple of machines behind it. I got complains that we have way more monthly traffic gigs more than we should so the first thing I look was check the ...