Fedora Networking :: Port Forwarding Does Not Work
Mar 22, 2009
I have a question regarding port forwarding. I have a fedora server, with two eth cards: eth0 ---> external IP, eth1 ----> LAN IP I use SNAT for connection sharing. I also have an internet domain hosted on this server... let's call it [URL] Anyway, one of our computers in the LAN has some kind of web server on it, which must be accessed from the internet on the port 23700.
So, using iptables -t nat -A PREROUTING -i eth0 -p tcp -m tcp --dport 23700 -j DNAT --to 192.168.1.25 (the IP of the network computer) Everything works perfectly fine from outside the lan. When I type [URL], I connect to that computer. My problem is that inside the lan, typing [URL] does not work! It only works if I enter it by IP 192.168.1.25:23700 Is there any way to make the server forward my request to that specific computer even if I'm inside the LAN?
I'm trying to understand and set up port forwarding with iptables. So far I've read a lengthy tutorial on iptables, and I've Googled for hours, searched this forum, but I've been unable to come up with a solution that works for me.The situation I would like to achieve is the following: on one machine, there is a TCP server running bound to its external IP, port 9999. I would like to let another machine connect to this TCP server on port 9000 by forwarding port 9000 to 9999.All the policies of the iptables chains are set to ACCEPT; and I have set net.ipv4.ip_forward = 1. I have no problems using SNAT/MASQUERADE on the same server machine.I have tried the following:
In order to test this rule, I started a TCP echo server on port 9999. I can connect to it on port 9999, but not on port 9000- this gives me 'connection timed out'. When I do 'iptables -t nat -L -v', I can see that the rule does get matched once per connection attempt.
I've been beating myself over the head with iptables and CANNOT get port forwarding to work. Here's my situation: Static LAN IP on eth0 Static internet IP on eth1 ip_forward is turned on by uncommenting in sysctl.conf Here's the output of iptables-save:
Code: # Generated by iptables-save v1.4.4 on Tue Mar 8 10:34:12 2011 *nat :PREROUTING ACCEPT [2443:347058]
[Code]...
Edit: by the way, the intended purpose of this machine is to server as a gateway and firewall. MASQUERADE is working, for whatever that is worth. And the host behind the firewall that is serving up http is definitely working too. All that is not working is getting hosts on the internet talking to hosts behind the firewall.
I have just set up shorewall on my router running Arch Linux. The external network is on eth0 and the internal network on eth1.I have set it up for masquerading and that works fine and I can open ports to the firewall. But I'm having trouble with port forwarding to my internal machines.The problem I have is that when port 22350 is forwarded to 192.168.1.3 on my local network, checking the port with nmap from a remote computer gives me:
I'll explain this in one sentence: Is it possible to program a port-binding shellcode in which people across the Internet can connect to, without being thwarted by the router blocking their data because the port its bound to doesn't allow port-forwarding
I am running Fedora Core 10 and KDE 4.2.1. My KTorrent is having trouble finding online peers lately. I suspect this is a port forwarding issue. I have set up my router to forward port 4444 (UDP) and port 56000 and more (TCP) to my machine's IP address. I have also set my local firewall (system-config-firewall) to allow these ports through.But when I try to test ports 4444 and 56000 via this Open Port Check Tool, it tells me they are closed
So I read a lot of posts on the Internet, but I don't understand which ports I have to open/forward for this.
On some posts I see a lot of ports, I don't want to do this.
If this is the case, and I would set up NFS through an ssh tunnel, then do I only need the ssh port and does this mean it will always work if the server is reachable through ssh?
I've recently installed OpenVPN on my dedicated server (Fedora) in order to have full internet access for all of my WinXP clients. In case somebody is interested in the details of the OpenVPN installation, I followed this documentation: Rootserver-as-OpenVPN-Gateway. The installation runs quire nicely, I'm able to surf the net and even file-sharing programs work on the XP clients - at least to some extent. There is a slight problem though: the file-sharing programs complain that they have a "NAT problem" or that they are "Firewalled".
Most likely, this problem can be addressed by configuring remote port forwarding (RPF) on the server. The only routing rules which I've added on the server during the OpenVPN installation are these: Code: # initialize natting for openvpn iptables -t nat -F POSTROUTING echo 1 > /proc/sys/net/ipv4/ip_forward iptables -t nat -A POSTROUTING -o eth0 -s 10.66.66.0/24 -j MASQUERADE Let's assume a certain application on a client is listening on e.g. port 1234. How do I configure RPF for this port on the server side.
I have a set up with a computer that has two network cards and is connected to two networks. Both networks connect to the internet via separate routers that have DHCP enabled. I can set one of the routers up to do port forwarding to the computer without any complications but if I want to do the same on the other router the port forwarding from it doesn't work and I can't reach the system.
I know for a fact that the services are accessible from both networks and both routers can forward ports to other computers in their network. The networks are 10.10.0.1/24 and 172.22.0.1/24. I've tried turning off iptables but that didn't change anything.
Is there any kind of setting that could prevent the interface on the computer to reject traffic using NAT or something?
If I disable the interface on the working network (ifdown eth1) then suddenly eth0 on the other networks starts accepting requests sent to it via the router that does the port forwarding. I do however want to emphasize that services work just fine as long as the requests originate from either of the networks they are on.
everything works fine. I can log in, and local port forwarding is done. Otherwise when I use the command:
ssh user@ssh_server -R 5500:localhost:5500 -p 22
I get an error "remote port forwarding failed for listen port 5500". However when I try remote port forwarding in WinXP by use of putty there is no problem...
I am setting up Apache (Fedora 12) inside my home network. From inside my home network I access it without any problem. I need to set it up to access it from internet. I have the following questions. Here is temporary setup for testing purpose. Internet-->ADSL modem (SEIMENS Speed Stream 4200)---> Apache (Fedora 12)
1. Do I have to do any kind of ports forwarding on ADSL modem. (There is no option to do port forwarding on Modem) May be I need different Model of Modem?? 2. I tired to Ping my real IP for modem form another computer from internet. I am even unable to PING the ADSL 's real IP. Why it is that?
I have a mail server on which I would like to block port 25 on my eth0 for everyone except our external spam filter. the problem is that I want our users to be able to connect via port 10025 which is forwarded to port 25, which then is blocked...
what should I add/change to set up port forwarding of port 1000 to ip 192.168.1.200. also how to get the answer sent by 192.168.1.200 follow the same route used by the data received through port forwarding.
I am using Fedora 14 x86_64 as the host and Windows XP under VirtualBox 4.0.4. I have added two ports (TCP and UDP) to the firewall settings in 'other ports' in the Fedora firewall setings. Do i need to do this?I noticed the port forwarding option in the Fedora's firewall settings which asks for either the ports to be forwarded to either local or an ip address. Do i need to do anything here?
In the settings under VirtualBox under Network adapter 1 (which is enabled) and attached to NAT, there is a port forwarding option in the advanced settings. Can the host and the guest port be the same number? If i use 'open port checker' to check if the tcp port is open in windows xp, will it work as it does in firefox under Fedora?
I have a machine with Ubuntu Server and VMware Workstation 7 installed. I have tried NAT port forwarding to gain Remote Desktop access to a Windows virtual machine, but it did not work for whatever reason. I've done this by editing the nat.conf file in the /etc/vmware/vmnet8/nat directory. Unfortunately it still does not work. Also, I would like to ask if it is possible to port forward using the virtual machine itself and not the host.
I have a ubuntu 9.10 on my desktop in my office and I have another ubuntu on my home desktop. Both machines are behind a router. I guess many people have already asked the same question: how to remote control the office desktop from my home desktop?Many posts discussed about solving this by setting up ssh and port forwarding. But my situation is that I cannot control the router in my office so I cannot set up any port forwarding for my office desktop. So I guess my question becomes how to remote control my office desktop without setting up any port forwarding on the office router.
I currently use a commercial VPN when working overseas for secure internet access.
I now also need to VNC to a home ubuntu desktop (which runs software 24/7 that I need to periodically check).
When overseas, I use a Ubuntu laptop and an Android tablet.
For the VNC I intend to use an SSH tunnel. So my question is: should I ALSO set up openVPN on the home computer (so I can stop paying for a commercial provider which routes all my traffic twice across the Atlantic...) or is it easier/better to use the SSH tunnel for the secure webbrowsing too? Something like a SOCKS proxy?
We have one linux machine in the office which happens to be an important firewall. I just know the basics and need to make one changeEssentially it is forward mysql traffic to another internal machine.This is the original rule (forward to 192.20.0.17) which is working
I have my mail application running on xxxx port in IPv6 and IPv4 enviornment on Linux machine (RHEL 5).I want to forward IPv4 request comming from windows client
I have a CentOS box which is Internet Facing. It has 3 LAN's connected to it which are for virtual machines.
I want to port forward port 445 to a machine on one of the LAN interfaces. I have tried various ways to get it done, but still cannot access that port from the interface. I definately know device hosting port 445 is live, as I can ping it from the CentOS box and use lynx to access it! (It's a web server)
I've been Googling about port forwarding iptables and even though there's result and I've applied it in my script, I can't make iptables forwading request to another machine so I decided to ask help.
eth0 is my Internet Interface (1.2.3.4 is the public ip) eth1 is my Lan Interface eth2 is my DMZ Interface
I have two PC's, one with slackware and one with arch, and I am trying to access the web server from the archlinux machine but i haven't manage to do that. The archlinux machine is connect to the internet via the slackware machine via a crossover cable: internet > eth0 (pc1) and ppp0 (the PPPoE connection, pc1) > eth1 (pc1) > eth0 (pc2)
pc2: ifconfig eth0 192.168.0.2 netmask 255.255.255.0 ifconfig eth0 up route add default gw 192.168.0.1 eth0 /etc/resolv.conf (The same DNS as the first PC)
And now the internet is working and on the archlinux machine, but I am not able to access the web server from LAN with a public IP. I tried many iptables port forwarding commands but none worked.
I have the wake on lan option enabled on my debian computer. If i wake it by sending:
-mac adres -internal ip in my home network -subnetmask -port 7
It all works fine, but when i try to do it from outside my network and change the ip address to the router adress it wont go on. I have also opened the port 7 in my router.
I have a server running debian squeeze and kvm to virtualize a Windoze box. It's setup to use NAT. This is because of limits on the network by the admin and unfortunately, there isn't a way to get around this.
I've setup dynamic port forwarding using Putty, SSH and Firefox.All works well when visiting normal websites (servers listening at port 80). But why can't I visit https websites?Nothing seems to be happening when I visit those.
I have a script to establish a reverse tunnel with other machine,My problem is to stop the tunnel. If I just kill the PID at sshtunnel.pids, ssh does not release the ports at the server side, so any new connection will fail for several minutes.Is there any way to signal SSH to exit gracefully?
This should be easy but for some reason its not working. I don't have admin rights on one of my local networks to open the firewall for port 80 to make my server accessible remotely (from the internet). I have a remote server (OpenVZ VPS) and I want to port forward so that [url]:8080 will point to my localhost:80 from the internet itself (i can get it to work on the remote VPS server's local network)...
How could I accomplish this? Basically, I am trying to serve webpages from behind a firewall using a VPS as a hub.
would it be possible for anyone to give me step-by-step instructions on how to set up port forwarding on my laptop? I've been using Karmic Koala and just upgraded to Lucid Lynx and not really bothered to port-forward before, so not too sure where to start - googling gives me a lot of terms I don't understand.
