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
0answers
13 views

Modify iptables rules when docker container has started

On my debian host I have a few docker containers, which I ran with -restart=always so, they start after host has rebooted. Some of them have exposed ports, and docker host process adds certain ...
0
votes
1answer
24 views

Windows translate external IPv6 to localhost IPv4

I have a machine running Windows server 2012, whose external IPv6 address is "2a01:4f8:190:7449::4". Let's assume it has no external IPv4 address, so the v6 address is the only way of accessing it ...
-3
votes
0answers
9 views

Windows routing don't pass packets [on hold]

I have a win server 2008r2 with routing and remote access role wan interface 54.93.71.23 domain.com lan interface 172.16.0.0 From internal network i can access to www except our domain.com Router ...
1
vote
1answer
18 views

How to connect to P2P clients behind a router?

Apologies if this question has been asked before, but I don't think any of the ones I've found are asking quite the same thing. I'm designing a simple P2P protocol whereby a known server provides ...
0
votes
0answers
9 views

SNMP through NAT when server has two IP addresses

We have an SNMP client talking to an SNMP agent through NAT. That works most of the time. We send an SNMP request e.g. from 1.2.3.4:12345 to 10.0.0.1:161 and get a reply from 10.0.0.1:161 to ...
0
votes
0answers
4 views

How to enable ping between machines connected in two interfaces? [migrated]

I have a linux board with two ethernet interfaces as mentioned below. eth0 connected to another linux machine (ad-hoc) eth0 on board 191.168.1.2 connected to Linux machine 192.168.1.3 eth1 on board ...
1
vote
1answer
24 views

Route new outbound traffic

I am looking for some iptables rules which can help me to route some traffic from a server : Client 1 ----| Client 2 ----| |----------| Client N ----| ssh, ...
1
vote
1answer
46 views

Using host's iptables to prevent access to docker-container's exposed ports

I have a host which runs a few docker's containers. This host has a few network interfaces, my goal is make some exposed ports from containers accessible only by certain interfaces, and prevent ...
0
votes
1answer
23 views

ip6tables snat don't work properly [closed]

I got three computers with these names: laptop, vds and home; vds is openvpn server; home is openvpn client. and, I got an ipv6 network 2a01:dead:beef::/64 vds has address 2a01:dead:beef::311 on ...
0
votes
1answer
21 views

Howto forward traffic between multiple OpenVPNs

I have an OpenVPN server which hosts two VPN networks, one is bridged and the other one is routed. See the following draft: The VPNs are working quite well while they are used in isolation. But if ...
0
votes
1answer
85 views

MikroTik - can't access webfig from external / can't SSH into router from external ip

Ok, here's the deal. Let's say that my public facing IP is 10.0.01. I can't webfig into 10.0.01 from external and can't SSH into mikrotik router from external IP. I can do it if I am physically ...
0
votes
0answers
4 views

Behind ISP NAT Firewall - Need to remotely monitor CCTV's [migrated]

Here's my situation: I have a DVR which is capable of allowing me to remotely view my shop CCTV's over IP.However, I'm behind the ISP's NAT firwall and have no ability to open ports on the router, so ...
0
votes
0answers
34 views

iptables DNAT packets into an openswan IPSEC tunnel

I have the following network setup: +-----------------------------------+ | | ...
1
vote
1answer
37 views

Apache can't access from wan on archlinux

Information: Archlinux via vmware Have ports 8080, 443 and 80 forwarded to the local ip from router running pfsense I can access the webpage from lan via local ip. My httpd.conf: Listen 80 ...
0
votes
0answers
76 views

can't connect aws VPC private instance to internet through NAT

trying to install a LAMP stack on an aws instance in a VPC private subnet using Scenario 2 described here: http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_Scenario2.html I've set everything ...
0
votes
0answers
45 views

CentOS 6.6 ignores iptables nat rules

I try to use iptables nat to forward incoming TCP traffic to another computer. I use following rules within nat table: -A PREROUTING -i eth3 -p tcp -m tcp --dport 8888 -j DNAT --to-destination ...
0
votes
1answer
31 views

c7200 IOS 15.x-x NAT/PAT issue

My problem may be just finger trouble, but after fighting with this for a day on what should have taken 5mins, I am getting fustrated. I am not Cisco Certified at any level, just a fair amount of ...
1
vote
2answers
62 views

TCP traffic on port 1433 blocked by NAT rules

We have a SQL server that is hosted on AWS, the SQL server it not directly accessible on the internet, it relies on a NAT box to route traffic to it. We are trying to set up a Linked SQL server from ...
1
vote
0answers
35 views

iptables keeps using old nat rules

I use iptables snat on my gateway to change local source ip addresses to external. The trouble is that after I change the rules (or even if I flush iptables nat table) gateway keeps using the old rule ...
0
votes
2answers
59 views

PFSense IPSEC VPN VLAN

We are integrating with a third party and they require the use of a L2L IPSec VPN for communication. I have successfully configured the IPSEC vpn and the tunel is up but now I cannot seem to have ...
0
votes
2answers
33 views

SIP Trunk for VOIP behind a SonicWALL

I appreciate this question is quite "out-there" but - has anyone had any success with VOIP over SIP behind a SonicWALL. We are having an issue with one-way audio inbound. Essentially, the person ...
-1
votes
0answers
11 views

DD-WRT: Remote SSH access doesn't work when OpenVPN client is enabled [migrated]

Problem description I have a DD-WRT router which I would like access remotely via SSH. The DD-WRT is behind an ADSL router which has port forwarding for port 22 enabled, DD-WRT SSH access and service ...
1
vote
1answer
121 views

Which SSL certificate would I need for external AND internal domain names?

This is a school-network. Official (outside reachable domain name) is bgschwechat.ac.at (www.bgschwechat..., mail.bgschwechat... and ftp.bgschwechat..) Internally the windows domain is named ...
0
votes
0answers
19 views

L2TP daemon server multiple IP

I have VPS with 3 public IP - Debian 7. I would like to have 3 L2TP damemons (one ip each) NATing traffic to each ip. Something like this l2tp_multiple_public_ip_diagram. I have set up l2tp daemon for ...
1
vote
2answers
52 views

NAT-ing with iptables rewrites source IP in logs

I have the following infrastructure in place: internet [outside 81.x.x.x] router [inside 192.168.1.1] | [network 192.168.1.0/24] ...
1
vote
2answers
88 views

router: ping fails at specific time for 40 seconds

my network looks like this: ISP cable --- ISP modem/router (2 in 1) \ \--- my router --- wifi connection --- computer 1 \----------- cable connection ...
0
votes
0answers
38 views

iptables, outside and inside NAT; Return traffic going out incorrect gateway

Overview (TL;DR at bottom) I have a third party firewall/proxy appliance which is running Linux (Ubuntu), and its routing and firewall engine is backed by iptables and the Linux (source)routing ...
0
votes
1answer
39 views

Windows Server as a PPTP Gateway

I have a Windows Server 2012 server at work, which is currently used as a domain controller, and an internet gateway. The current internet connection uses a USB dongle, which appears like a standard ...
0
votes
0answers
81 views

FortiGate 310B public ip pool into internal port

I have a FortiGate 310B with WAN port with /27 public IP pool from the ISP. The WAN port is configured with primary IP 1.1.1.1/27 I would like to provide servers within the Internal port a public IP. ...
0
votes
0answers
65 views

Cisco ASA firewall blocking requests to internally hosted DNS server

I have a DNS server behind a Cisco ASA firewall. The Cisco firewall is performing NAT. When inside the network, I can NSLOOKUP directly to the server. When the client is external, requests time out. ...
-1
votes
2answers
40 views

Reaching Local Network which is under NAT with no public IP

I have a place called (lets say) REMOTE. REMOTE is connected to the Internet using 3G/4G Modem + Router. Unfortunately my mobile Internet provider does not give me public IP address. In REMOTE I have ...
0
votes
0answers
39 views

NAT and S2S VPN to Azure issue

I can connect to the VNet with on-premise WS2012 R2 RRAS S2S VPN connection successfully. The on-premise WS2012 R2 has two NICs, "External" and "Internal". "External" NIC is facing to a public IP ...
0
votes
0answers
26 views

NAT and DMZ Cisco ASR 1001

OHAI got weird situation on my two Cisco ASR 1001. First one is WAN router, the other one is CORE distribution inside the office. So I've got one public IP on my WAN, and got this particular line: ...
0
votes
0answers
54 views

Change source IP for packet incoming in VPN tunnel

The following configuration allows me to change the source IP from 192.168.0.0/24 to 172.16.0.100 when hosts going to 10.0.0.100 and it works. But I can't achieve this goal for the hosts incoming from ...
0
votes
1answer
51 views

Cisco IOS - Problems with NAT and port forwarding

I have a problem forwarding ports. I have configured a NAT pool of 1 address (192.168.5.2) and assigned that address to the WAN interface. I assigned networks to the access-list, and bind the two ...
3
votes
1answer
61 views

Forwarding a port on the loopback interface to a remote IP/port

I have two Docker containers that I'm trying to network together in a specific way. Container A is running a Redis server on port 6379. Container B is running an interactive shell and needs to access ...
1
vote
1answer
94 views

AWS public subnet autoscaling group with outbound NAT

I have seen this question : Static IP address for outgoing traffic from AWS autoscaling group but it doesnt seem to fit exactly what im trying to do. Here's the scenario: I have a autoscaling ...
2
votes
2answers
125 views

iptables drops packets after POSTROUTING

I have a malware analysis environment that will intercept traffic to arbitrary domains and Internet services using InetSim. I have a sandbox that has its DNS server set to the InetSim instance, and ...
1
vote
2answers
39 views

Trying to use source routing on two different interfaces

I have defined the following rules: -A POSTROUTING -j SNAT --to-source [publicip] -A POSTROUTING -j SNAT -d 192.168.0.0/24 --to-source 192.168.0.6 Basically, I want only the private network to go ...
3
votes
5answers
261 views

Router limits network performance but its CPU load isn't 100%

I'm using a PC Engines APU device running FreeBSD as a NAT router. The setup is very usual: one WAN connection and one LAN connection. Theoretically, WAN connection is 800/40 Mbit/s and the LAN one ...
2
votes
3answers
96 views

Cisco ASA NAT - internal host see its public ip

I have a server hosted by a provider which uses Cisco ASA to do nat. The problem I have is that the internal server that is nat-ed with a public ip will see its public ip as source ip. This basically ...
0
votes
0answers
60 views

Chaining two containers with docker

I have two containers that I have chained them together, so traffic that comes to container 2, first passes by container 1. I set container 2 --net=none. Host --- Container 1 --- Container 2 this is ...
1
vote
2answers
83 views

NAT a single IP using 2nd WAN Internet

I have a mikrotik RB750 (6.22) acting as a gateway for my LAN. Here is the basic configuration: Ether1-WAN1 (1.1.1.10/24) IPs are hidden for privacy Ether2-WAN2 (2.2.2.20/24) Ether5-LAN ...
0
votes
0answers
115 views

Why can't I SSH to this AWS NAT instance in a public subnet?

For experimentation purposes, I’m trying to setup an AWS EC2 inside a VPC that has both public and private subnets as described in this tutorial. However, when I try to SSH in step #2, it fails ...
0
votes
1answer
27 views

How to find how a port has been forwarded from main server to hypver v vm

I must appologise for being a novice in server administration but I have somehow been given the responsibility and I have spent a long time reading up on this. The issue I have is that the previous ...
0
votes
1answer
173 views

Use Openswan / IPSec on Ubuntu server to connect to existing Openswan VPN - NAT broken

I have an existing Openswan VPN, all working fairly well with Windows, Mac and Phones. [Office 192.168.0.0/24]---[VPN A.B.C.D]----[Internet]---[Home Routers (NAT), Dynamic IPs]----[Workstations] Now ...
0
votes
1answer
45 views

iptables port forwarding from public ip but not from 127.0.0.1

i have an issue with my network setting and i need a port forwarding a bit advanced. I need : - All packets that arrive on my public_ip on port 54321 to be forward on port 12345 but i don't want any ...
1
vote
1answer
113 views

Asterisk behind NAT sets wrong Contact Header

I'm using SIP with asterisk 13.1.0 behind a statically configured NAT. The servers private_ip differs from the public_ip, where I can reach it. I've already set these options in the sip.conf file. ...
0
votes
2answers
36 views

Port forward for SSH works to one system but not another

I have two systems sitting on a NATed network. When I forward port 22 to system A, I am able to connect directly. When I forward port 22 to system B, I am not able to connect. I am, however, able to ...
1
vote
1answer
34 views

IP forwading amazon ec2 another server IP

I use this command in windows azure (NAT), to redirect all requests to another server with other IP iptables -t nat -A PREROUTING -i eth0 -d 10.240.154.15 -j DNAT --to-destination 192.188.47.63 ¿ ...