Questions tagged [nat]

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.

650 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
5 votes
0 answers
4k views

NAT64 configuration with tayga on Debian 6

I'm trying to implement NAT64 with tayga on my server and came to a point where I'm not sure how to proceed. My server is connected via one IPv4 address and one /64 IPv6 address block to the internet....
Georg Bretschneider's user avatar
5 votes
1 answer
987 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 (...
Kevinoid's user avatar
  • 171
4 votes
1 answer
845 views

Finding google unusual traffic

We are a small Internet provider. In order to get Internet access we are using NAT (10-20 users per one public IP). And lately we've met with Google blocking services (captcha and full block) and we ...
Alex's user avatar
  • 231
4 votes
1 answer
386 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 1.2.3.0/...
user160205's user avatar
4 votes
1 answer
2k views

port redirection on solaris 11

I'm trying port forwarding on solaris 11. I have a mechine behind a server that use solaris 11. I try to access that mechine from the external port, and forwarded by solaris 11 mechine to that machine ...
mo3lyana's user avatar
4 votes
0 answers
804 views

Oracle Solaris 11, ipnat - rdr not working with remote destinations

I'm trying to reverse proxy traffic coming in on port 8100 at one machine to another. The receiving host is an oracle exclusive zone as is the destination machine. On the incoming zone I have ...
Guenni's user avatar
  • 141
3 votes
0 answers
2k views

Enable bidirectional UDP communication between Windows host and Docker container

I have a UDP server on a Windows 10 host, on a fixed port (let's say 1234). All I want is to set up a communication between this server and a client in a Docker (Debian-based) container (Docker ...
timot.cool's user avatar
3 votes
0 answers
884 views

Supporting IPv6-only clients in connecting to IPv4-only hosts

I have a service that aggregates third-party content, but ultimately end-users connect directly to the third parties they're interested in. The problem I'm facing is that many users are connecting ...
Tom's user avatar
  • 131
3 votes
0 answers
1k views

Effective way to detect NAT network inside of Linux

In Ubuntu I need to detect if the Network ip address is a NAT system, (not need STUN ) I thought check the ip class range type like this: Check if IP address is in private network space But I saw ...
user3185638's user avatar
3 votes
1 answer
6k views

Add-NetNatStaticMapping not port forwarding to local VM

I'm running windows 10 build 1809 and have hyper-v installed. I have a Linux machine running behind a NAT with internet connectivity working on IP 10.0.5.5. I basically followed instructions on the ...
Mark's user avatar
  • 211
3 votes
1 answer
12k views

Using iptables TPROXY instead of REDIRECT

I'm running Debian 8. I'm trying to intercept all packets, and are currently using iptables for this: iptables -t nat -A PREROUTING -p tcp -j REDIRECT --to-port 5000 This seems to work, but it ...
Alfred Balle's user avatar
3 votes
0 answers
71 views

CISCO ASA: Static external 1:1 NAT, but also with Internal Access

We have a NAT rule in our ASA 5525-X here, which basically makes it so that 1.2.3.4 on the outside and 10.1.9.10 on the inside are essentially NAT'd. That is, you can reach 1.2.3.4 on the outside, ...
Thomas Ward's user avatar
3 votes
0 answers
648 views

Getting NATed traffic returned back to the right interface

On a custom board (running a 4.x kernel), I have two physical ethernet interfaces and one radio modem that gives me a ppp-interface. iproute2 has been installed, and I am using nftables (not iptables)....
mroek's user avatar
  • 31
3 votes
0 answers
1k views

IPTables DNAT Exemption

TL;DR - I'm looking for a way to send all my external traffic through a proxy server but not send all my internal traffic through a proxy server. How can I achieve this? My end goal is to forward ...
MikeSWelch's user avatar
3 votes
3 answers
3k views

Bind docker container ports only to specific outside server address

This is the first time i address such a network "problem" to solve with docker and i need some inputs. This is my situation: Ubuntu 14.04 running NginX, ufw as firewall and docker containers to run ...
sciakysystem's user avatar
3 votes
1 answer
255 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. ...
NarūnasK's user avatar
  • 378
3 votes
0 answers
1k views

Openstack seems to not map internal IPs to local network properly

I have a very confusing issue which I can't seem to resolve. I followed a guide by Loic Dachary on installing Openstack Folsom on Wheezy, and deployed it on two hosts: a cluster node, and my ...
user991710's user avatar
3 votes
0 answers
1k views

Linux IPsec VPN and SNAT

I'm trying to connect my network to an IPSec VPN, and for this my connexions need to come from a given domain. The network is the following: Internal network eth1:10.0.0.1/14 eth0:1.2.3.4 ----...
ebernard's user avatar
3 votes
0 answers
984 views

How to configure opennebula for allowing a cluster private network to host images with public IPs

I am installing open nebula 3.4.1 for running virtual machines a (kvm based) cluster made of 5 computers: a front-end machine having 2 network interfaces and 4 slaves machines with a single network ...
user1456486's user avatar
3 votes
3 answers
2k views

sonicwall vpn and NAT

I have a site-to-site VPN set up with a vendor. Let's say the tunnel endpoints are 192.1.1.101 on my side and 192.1.2.0/24 on the vendor's side (which get's NATted to their LAN of 10.x.x.x). This is ...
dan's user avatar
  • 426
3 votes
1 answer
1k views

iptables SNAT return traffic not reaching client

I have the following design in place: client linuxserver destination 192.168.160.34 192.168.163.196 192.168.18.1 I can ping server from client ...
Farhad Farahi's user avatar
3 votes
1 answer
1k views

How to mimic "DMZ Host" or "Default Host" NAT funcionality with iptables?

My previous DSL modem had a function called "DMZ Host" (which in other platforms seems to be named Default Host). When you select a computer in your network to be the DMZ Host, it forwards every non-...
Joe Mirabil's user avatar
2 votes
2 answers
4k views

Proxmox on Hetzner, single IP, routed configuration

Alright, I'm at my wits end. I am trying to configure a ProxMox on dedicated server at Hetzner, which has one public IP, so I want to use NAT for VMs / containers. I read all the manuals, and tried to ...
sgzmd's user avatar
  • 121
2 votes
0 answers
697 views

MetalLB on a host with multiple NIC

I need help with some deeper networking stuff. Hopefully somebody can help me or at least push me to the right direction. At the moment I have a two node bare metal (VPS) kubernetes cluster setup with ...
MattDog's user avatar
  • 21
2 votes
0 answers
730 views

NAT with strongswan - howto?

Network Topology I have the following setup where Office 1 and Office 2 have the same IP address range (192.168.0.0/16) and both are using strongSwan running on Ubuntu VM (with two NICs one connected ...
Waddah Shamroukh's user avatar
2 votes
0 answers
5k views

Howto configure Wireguard on Linux router to route all traffic from LAN to remote wireguard VPN server

I've an Armbian linux on a NanoPi R1 running. It routes all traffic from eth1 (LAN static IP, dnsmasq for DHCP/DNS) to eth0 (WAN dhcp-client) via IPTables NAT/Masquerading. That works fine. A client ...
TRW's user avatar
  • 518
2 votes
0 answers
474 views

Is there an ipv6 equivalent for net.ipv4.conf.all.route_localnet

Is there an ipv6 equivalent for net.ipv4.conf.all.route_localnet ? (According to nftables ip6 route to localhost/ ipv6 nat to loopback, there isn't). If not, how the use case described in Port ...
AlonaK's user avatar
  • 21
2 votes
0 answers
5k views

Change default interface docker container

I'm struggling with this problem for two days. Assumptions: Docker network (and interface) named docknet type bridge subnet 172.18.0.0/16 Two interfaces eth0 (Gateway IP: 192.168.1.1, Interface ...
Luca O's user avatar
  • 29
2 votes
0 answers
204 views

Not able to ping VM and/or mount NFS after changing IP via POSTROUTING

Imagine the following setup. I have a machine A which exports a network share and is reachable under, say 1.1.1.1. A second B machine with an IP, say 2.2.2.2, is mounting that share, everything's ...
xxx's user avatar
  • 21
2 votes
0 answers
376 views

TCP KeepAlives with NAT?

We have a Network set up like this: MQTT Client -- TCP Forward (Netscaler) -- TLS Termination + TCP Forwarding (HAProxy) -- MQTT Server For several reasons we needed to turn on TCP KeepAlives in ...
peez80's user avatar
  • 191
2 votes
1 answer
9k views

pfSense - NAT not working

I have a pfSense on Proxmox VM. I have two IP addreses configured: WAN: xx.xx.88.24 -> public IP accesible from internet LAN: 192.168.1.100 -> corporate intranet I want to access an internal ...
xavi.dive.kite's user avatar
2 votes
0 answers
724 views

Forwarding Fragments with IPTables / FirewallD

I have a linux (openSuse Leap 15.0) computer that's connected to a cable modem using PPoE (hopefully not relevant to this. EDIT the ppp0 interface has an mtu of 1492 but the eth0 interface it is "...
andrew cooke's user avatar
2 votes
1 answer
2k views

AWS private subject cannot hit S3 using VPC endpoint

I have a private subnet in my VPC. I've sshed into this instance from a public subnet. Using a nat gateway, I'm able to run aws s3 ls and see all my buckets with no issues. Once I delete the nat ...
John Lippson's user avatar
2 votes
0 answers
490 views

How to NAT ports on VPS connected to distant network through OpenVPN

Could you please tell me what IPTABLES rules i should write to my VPS (running Debian 8) to do NAT on port 8082? I need port 8082 to be addressed a local device on my LAN (192.168.0.100) User should ...
Laurent Coulon's user avatar
2 votes
0 answers
359 views

pfctl not relaying SYN, ACK packet after NAT

I am trying to relay SSH connections from LAN hosts to hosts beyond VPN. Only one router host in the LAN has VPN connection to be reused by other hosts in LAN. Below is pfctl configuration on the ...
Oleg's user avatar
  • 21
2 votes
0 answers
2k views

Why would I get ping replies from a private IP outside of my subnet?

I have a computer with 2 network adapters, each on its own subnet. One is our private LAN, 192.168.1.0/24, the other is for the internet. The internet subnet is 10.251.85.161/27. When I ping-...
HypnoToad's user avatar
2 votes
0 answers
2k views

Forwarding traffic with one ip proxmox

I have a hetzner dedicated server, and i've installed proxmox. I have only one ip and i need to forward traffic and ports to VMs. I've followed proxmox network tutorial with no success: can't access ...
buzzing's user avatar
  • 21
2 votes
1 answer
1k views

Mikrotik strictly specify masquerade NAT ports range

I want to limit TCP/UDP ports which can be used for masquerade NAT on my Mikrotik router. For example, I want to use only 40000-65535 TCP ports range and 20000-65535 UDP ports range for masquerade. ...
Nikita Petrov's user avatar
2 votes
0 answers
508 views

SmartOS: How to configure IPFilter (IPF) loopback firewall rule?

I have a SmartOS machine with one external IP address. One of my websites needs loopback access. However, if I try to curl https://www.example.com it simply times out from within a zone. From within ...
TylerDurden's user avatar
2 votes
0 answers
7k views

iptables forward all traffic through proxy

I need to redirect all tcp traffic coming out of local programs to the interface that is able to connect to a proxy server. According to this picture I need to add rules to the OUTPUT chain, but ...
e109848's user avatar
  • 23
2 votes
0 answers
412 views

Can't ping remote host through nat on ipsec enc0 (mtu=0)

I'm up ipsec vpn to remote host. Since the remote host accepts only one ip i'm up nat for local net on enc0. Ping from ipsec host is ok: PING 172.20.162.150 (172.20.162.150): 56 data bytes 64 bytes ...
Morry's user avatar
  • 21
2 votes
0 answers
77 views

OpenBSD login.conf statement for nat-translated radius clients to ID as public address instead of private?

I'm on OBSD6.0 behind a NAT firewall and attempting to authenticate against a RADIUS server on the outside. The RADIUS server gets the internal (private) address of the client system, not what the ...
danno's user avatar
  • 768
2 votes
0 answers
348 views

how to change windows 2016 docker dynamic / ephemeral port range

So I've been trying to use Windows Server 2016 docker on AWS EC2 and it seems by default when the docker container try to access the internet, it uses an ephemeral port range of 1024 and above? Is ...
Sleeper Smith's user avatar
2 votes
0 answers
1k views

Packets not hitting POSTROUTING rule, leaving interface unedited

I am trying to configure routing from my local network in vmbr1 out to the public interface vmbr0. My computer has IP 192.168.0.1 on the vmbr1 interface. I have configured following post routing rule: ...
Scintillo's user avatar
  • 121
2 votes
0 answers
448 views

Linphone iOS behind CGNAT sets wrong Contact Header

We are using Linphone client on iOS over Verizon network. Our client sends wrong IP address on Contact header at 200 OK message as a response to INVITE message from Asterisk. SIP trace Our client's ...
Falieris Ilias's user avatar
2 votes
1 answer
3k views

Iptables : forwarding SSH traffic according destination IP

I have 2 servers : One that receives connections from outside my LAN and another (inside the LAN) that I aim to access from outside via ssh. There are prerequisites : I can't access to my SSH services ...
Pierre-Yves Le Dévéhat's user avatar
2 votes
1 answer
2k views

Amazon Linux - iptables NAT rules not matching GRE traffic

I'm trying to prototype something in AWS VPC/EC2, but I can't get my NAT rules to work. I have the following setup (all instances running the Amazon Linux AMI): GRE Tunnel between instances 10.0.0.10 ...
Justin Smith's user avatar
2 votes
0 answers
1k views

Routing public IP addresses to customers in a WISP setup

We have a fibre leaseline with a /29 range for our pfSense WAN port 61.179.145.40/29 So the WAN of our pfSense box is 61.179.145.42 with a gateway of 61.179.145.41. Our ISP has also routed 61.179....
dynamicuser's user avatar
2 votes
0 answers
3k views

Virtual IP Pool for NAT with StrongSwan VPN

I'm trying to wrap my head around a site-to-site VPN configuration using StrongSwan that will allow remote sites to connect to our AWS VPC. The catch is, the remote gateways will potentially be using ...
anders's user avatar
  • 191
2 votes
0 answers
249 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 ...
koresh's user avatar
  • 21

1
2 3 4 5
13