Networking :: Shorewall: Port Forwarding Port Is Closed Even After Forwarding?
Dec 12, 2009
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:
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 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.
sudo ssh -L 750:192.168.123.103:873 username@192.168.123.103It does exactly what it's supposed to do, but how do i edit / remove this rule?Is there some config file where i can alter the forwarding? How does it get stored?Im using Ubuntu 10.10Server Edition (allthough i recon it would be pretty much the same across all versions
I'm not that great with mailservers, and just been thrown a curveball with a MS Exchange environment for which there is apparently no solution... yeah, right. But is there a workaround?
The problem is that the site mail (SMTP) needs to be sent via port 26 instead of the commonly used 25. Port 25 is mapped to a mailfilter, which apparently causes havoc with some of the mail, and the techs that have been on site trying to coax the Exchange server to co-operate have said that the only way would be to get rid of the filter.
The problem is that there are number of apps that are unable to have the outgoing port changed and so keep sending mail out on port 25.
I look after the Unix/Linux side of things at work, and I was wondering if there was an easy way to set up a Ubuntu box to receive mail on port 25 and just forward it to the MS box on port 26? So, in other words (and I hope this makes sense): monitor port 25, and forward whatever comes in on port 25 to the server on port 26. Simple portforwarding, or is it? What steps do I need to take?
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 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 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 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 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.
I have two nic cards installed in a Lucid LTS server.
eth0 is static using address 192.168.0.235 gateway 192.168.0.1 netmask 255.255.255.0
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I have my Qwest DSL modem port forwarding port 80 to 192.168.3.235 however this doesn't seem to work if I have both cards running. If I remove the second card (eth1) and reconfigure eth0 to use 192.168.3.235 I can port forward into my webserver.
I have logged into my router and set up port-forwarding on port 22. I can log into the machine fine from a machine on the local network using the machines internal IP but when I try to log on from a remote machine using my router's external IP or my DyDNS host-name I get a message saying "connection refused" or "connection timed out." I have configured port-forwarding on the router and the firewall rules says that port 22 is open but when I nmap my routers external ip it says that only port 23 and 80 are open. I am very new to linux and networking.
I've used wake on lan and SSH on the local network for some time now. I also used SSH to mount a filesystem (SSHFS / sftp, same thing, right?) and I could forward X11, loved it. I used both these options for my convenience. So I decided it was time to open up some ports on my router (Linksys WRT320n running dd-wrt) and try to set up a remote connection. This actually worked after some time, so I'm now able to turn on my home computer from the Internet (school in my case) and then log in to it through SSH. I set this up using other ports then the default ports. Something like this (these are not the actual ports I use, just examples):
port 2112 -> port 9 (for wol, wake on lan) port 2113 -> port 22 (for SSH)
This information might be useful: I set this up using public and private keys. This is necessary for SSHFS to work properly I think and it also makes it more secure. And then I found (and had some presumptions that this was going to happen) that both SSHFS and X11 were not working. I'd rather not open up more ports on the router for security's sake though, so I'm asking for other solutions. And if there really aren't any other solutions then which ports to forward. And if forwarding is really necessarily then how to make the client use port 2114 for SSHFS and 2115 for X11 so I can forward those ports to the default ports.
I'm trying to set up very simple UDP port forwarding, but can't seem to have good results. I read trough netcat and iptables manuals, but can't seem to figure things out. my setup is the following:
I have machine1, listening on UDP port 49000. I have machine_fw, which accepts connections on 59000, and forwards all this to machine1:49000 (and returning traffic too) I have machine2, which will connect to machine_fw:59000, and this way communicate at the end with machine1:49000, as machine_fw is taking care of forwarding is there an easy way to achieve this?
