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

1
vote
0answers
23 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
0answers
17 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. ...
0
votes
0answers
19 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 ...
0
votes
0answers
6 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
16 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 ...
0
votes
3answers
101 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. ...
-1
votes
0answers
17 views

OpenSwan VPN pings but other traffic fails

I'm setting up a VPN server using OpenSwan, to establish site to site VPN. Site A has the OpenSwan server, sitting behind the SOHO router (ports 500 and 4500 forwarded and default route to subnet B ...
0
votes
2answers
29 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. ...
0
votes
0answers
27 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 ...
-1
votes
1answer
57 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 ...
1
vote
0answers
37 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
26 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
23 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
74 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
53 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
27 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?
1
vote
1answer
81 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
37 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
17 views

Cisco ASA Access anyconnect from inside IPsec tunnel

I have a Cisco ASA on a dynamic WAN IP with a IPsec site-to-site tunnel to a remote linux host in a datacenter with a static WAN IP. All non local traffic is tunneled and the datacenter end is the ...
0
votes
0answers
31 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
47 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
56 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
38 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
27 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 ...
0
votes
1answer
74 views

Is it advisable to use virtual Linux server installed on i5 / 8GB / 500GB desktop class computer? [closed]

We have CentOS 4.3 P4 / 512MB /Linux server installed somewhere in 2006-7. This machine has three network interaces for leased line, broadband (backup) and LAN. We use Sendmail, Fetchmail, NAT, Squid, ...
0
votes
1answer
70 views

postfix - connection refused from behind NAT

When attempting to telnet postfix from a different host in the same LAN through the FQDN (and thus the LAN's public IP), the following error occurs: root@mailer:/var/log# telnet mail.domain.com 25 ...
0
votes
0answers
66 views

Trouble with port 80 nating (XenServer to WebServer VM)

I have a rent server running XenServer 6.2 I only have 1 public IP so i did some NAT to redirect ports 22 and 80 to my WebServer VM. I have a problem with the port 80 redirection. When i use this ...
1
vote
1answer
65 views

Iptables prerouting based on destination's DNS name?

I've got a question concerning iptable prerouting. I'm not that familiar with networking/routing/iptables so I hope this is not a stupid question, at all. So I ask for your understanding and ...
0
votes
0answers
76 views

UDP packets are not reaching iptables NAT table

I'm trying to redirect UDP incoming packets to port 4000 to another IP with iptables: iptables -t nat -A PREROUTING -p udp --dport 4000 -j DNAT --to-destination 192.168.100.20 Unfortunately they ...
0
votes
1answer
85 views

Allowing a private subnet EC2 access to the internet - Amazon AWS

I have a VPC "VPC with Public and Private Subnets" created via the VPC wizard which should include NAT for the private subnet VPCs however it's not working. They are unable to browse the internet, ...
0
votes
0answers
30 views

Using NAT with iptables between corporate network and firewall'd corporate network

At work we have a firewall between two networks. I was told they opened up the two ports for me but I needed to modify the IPtables to allow packets to go through. I'm not familiar with the correct ...
0
votes
0answers
33 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 ...
0
votes
0answers
59 views

Cisco router: expired translations not timing out

Why would a Cisco router stop removing expired translations from the NAT table? For example: #show ip nat translations tcp verbose tcp <loopback>:60576 <inside>:60576 ...
0
votes
0answers
74 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
votes
1answer
264 views

OpenVPN tun routing (can ping tun interfaces) with mikrotik and NAT on both ends

Problem The Mikrotik site is unable to ping anything on the server site. The Server site is less important right now. OpenVPN Server config is on LINUX port 1194 proto tcp dev tun ca ca.crt cert ...
2
votes
1answer
66 views

Routing DHCP traffic over the internet

i'd like to know if it's possible for the internet to be between a DHCP server and the network it's "assigned" to? so basically, something like this: -------------- ------------- ...
1
vote
1answer
143 views

Routing between 2 different subnets on 2 different interfaces in SonicOS

I'm having a bit of a problem allowing traffic between two of my subnets. Here's the structure I've built. The X0 interface has our windows server on it and it handles DHCP/DNS, etc. X1 has the WAN ...
2
votes
1answer
76 views

Can I use NAT64 to route public IPV6 traffic to internal IPV4?

I have a bunch of public IPv6 addresses and some services that run IPv4 only. Can I use NAT64 to connect these services? Is there another solution like a proxy or something?
0
votes
0answers
41 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
votes
0answers
98 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 ...
1
vote
1answer
71 views

Firewall setup Huawei 4G with DMZ

Network topology: ISP1 | | Alternative ISP 4G | | | Huawei 4G with DMZ | | ...
0
votes
1answer
69 views

Cisco 887VA Port Forwarding Not Working

I have a Cisco 887VA connected to our BT Business Broadband line. We also have another modem on a seperate connection which also handles our DHCP. The Cisco is plugged into our network switch, as is ...
0
votes
1answer
89 views

FreeBSD jail with IPFW with loopback - unable to connect loopback interface

I am trying to configure a one IP jail with loopback interface, but I am unsure how to configure the IPFW rules to allow traffic to pass between the jail and the network card on the server. I have ...
1
vote
0answers
33 views

Setting up a web server behind a ZTE NAT [closed]

down vote favorite I have developed a web app in Java using netbeans and running on a glassfish server attached to netbeans. I would like to show this to some people but I can't get it running across ...
1
vote
0answers
34 views

Weird socket behavior in VirtualBox (NAT + PAT)?

I have a Linux VM with NAT and PAT configured. Let's say ports 2000 and 2001 are forwarded to the VM. These ports are also configured for external access on a device such as a router using a domain ...
0
votes
1answer
37 views

2 NIC vs NAT for exposing server

I'm trying to virtualize some applciation using citrix. so I have to expose the secure gateway to Internet (put it in DMZ). my question is which is better practice ? 1 - using 2 physical NIC, one ...
0
votes
0answers
34 views

With split routing configuration returning packets don't reach their sender

I am trying to configure a split routing setup, where all traffic goes out the default eth0 interface, while packets from a single client are routed via tun11 (OpenVPN interface). So far I've come up ...
0
votes
1answer
85 views

can I use DNS with private NAT addresses?

I want to build a service that dynamically creates VMs and assigns each VM a public DNS record which could be a full domain or a subdomain. Assume the VMS all live on a single host. The VMs will have ...
1
vote
0answers
46 views

Poor large transfers behind NAT on Centos

I have the following set up. A Centos 6.5 VM running on an ESX host, with a public IP4 address. It is acting as a gateway for (a bunch of) other Centos 6.5 VMs that are only connected to a virtual ...
-5
votes
1answer
41 views

NAT444 on vodafone 3g [closed]

I am using Huawei K3765 with vodafone as ISP. When i tested my IP with ipconfig, private IP is assigned to me. I dont think this device act as a router, since its just a 3g donle. This created the ...