I have setup a simple HTTP java server running locally on port 8000. It simply prints a message "Hello world" when a request comes. When I try to ping it from the browser by running http://localhost:8000/test I get my message printed.
I want to get the same results from another computer that is not local. When I try to use my public IP lets say http:/43.xxx.xxx.xxx:8000/test (even from the same machine) I get an ERR_CONNECTION_REFUSED .
I probably suspect that has something to do with the firewall. Can anyone guide me a little more because I lack the experience?
Thanks in advance
You don't specify what host OS your server/firewall is running so I'll keep this generic...
Without knowing your application, it seems like the server is sending a reset (RST packet) when the first SYN packet shows up indicating that the port (on that interface [your external]) is closed. You can do a quick port scan from here (https://mxtoolbox.com/PortScan.aspx) if you don't have access to a remote machine to test with. Odds are, TCP/8000 will not be open.
If it is, in fact, closed, you'll have to look at the firewall that your host OS is running and find out how to allow TCP/8000 to your host. In a major firewall vendor, your rule would look similar to this:
Source: Any
Destination: Your Public IP Address
Service: TCP/8000
Action: Allow
Logging: Full
That being said, you mentioned this was a PC so look into "iptables" (if you're running *nix) or the Windows Firewall (if you're running Windows) on adding firewall rules (Unfortunately I just joined and can't ask questions/comments, yet).
If you really want to find out what packet is being sent, run a tcpdump on your external interface (let's say eth1) (assuming your remote IP is 1.2.3.4 and your home public IP is 4.5.6.7):
tcpdump -nn -vvv -e -s 0 -X -c 100 -i eth1 host 1.2.3.4 and host
4.5.6.7 and port 8000
Here you're looking for the SYN/SYN-ACK/ACK for a successful TCP negotiation or SYN/RST if there is a firewall rejecting (not dropping) the TCP stream to the port.
Once the port is open on the host OS firewall, take a look at the application to make sure it's configured properly. If this were a standard webserver, you could take a look at the configuration files for the "Allow from" directives to make sure that everyone can access the site. If this is a custom application that you've created, you'll have to check this yourself.
I finally solved my problem. I needed to open a forwarding port in my router that maps my local ip address to the public. My router is TP Link so this what I did:
http://www.tp-link.com/us/faq-72.html
Also in order for this to work every time and not to have to reconfigure this every time I reconected to the router (because I get a new local IP), I have created a static local ip for my server following this guide:
http://www.tp-link.com/us/faq-182.html
Thanks for all the replies.
Related
I am trying to access my local [WAMP] webserver from any remote devide. I am so far able to access it from a device inside the LAN, but fail to do so from outside it. As far as i know, port forwarding is how we achieve this. But currently unable to do that correctly.
Present error when trying to connect :
Some of the articles which i have followed so far are:
general-port-forwarding-guide
how-can-i-access-my-server-from-outside-of-my-lan
how-to-expose-a-local-development-server-to-the-internet
The main steps which i follow are as follows:
Make sure server is accessible inside LAN.
Open router's port forwarding settings and port forward the set static ip address (in step 1). Set port 80 and 8080 for communicating.
Access the server via my public ip (can check public ip and if forwarded port is accessible from here)
This is a temporary solution for testing purposes only with 8 hour server connection duration time limit (and a limited no. of server connections):
access_local_server_remotely_for-Development-And-Testing-Only and here is a video guide about how to use it.
I have setup a CentOS VM to test Hadoop. I set a network interface in NAT mode with a paravirtualized network type interface. Port redirection for SSH (TCP 22) works without issues. However some other ports do not seem to fully work (9870, 8042, 9864). I can see some "action" happening. Let me give an example for port 9870.
These are my rules (remember I said the SSH rule works without issues):
RulesX TCP 127.0.0.1 59870 10.0.3.15 9870
When I try to access http://127.0.0.1:59870 I get automatically redirected to https://127.0.0.1:59870 but eventually I get a ERR_TIMED_OUT error.
Tracing the traffic on the VM, I can see the traffic coming in but I cannot see any response back (I have one single network interface):
I am not sure what else to look at.
Any idea is highly welcome. Thank you!
More than likely, you need to open the non-standard ports on Centos firewall.
Open firewall port on CentOS 7
Sorry for the basic question but im a complete noob on those matters.
I have a cloud server where i run a jup[yter notebook server, which normally is run on port 8888.
However when i try to connect to it from work, it doesnt work, which i suspect is due to the firewall.
I can connect from work to a regular ssh session through port 22 or 443.
However the jupyter notebook refuses to be run on those ports, probably because they are allocated already.
I tried to run PortQry to get the open ports on my work server (which is windows) and it reurned port 50248. I tried to have my jupyter server to listen on that one but it didnt work.
I also tried to scan the open port of my work server, but i received a warning from AWS! And the few ports that were returned as seemingly opened didnt work either when i set up my jupyter notebook to listen on them.
I would like to understand:
On my own server: How can i identify which port the jupyter server program can listen on?
On my work machine: How can i identify which one of my own server port would be let through the firewall of my work?
You need to use SSH local port forwarding.
https://help.ubuntu.com/community/SSH/OpenSSH/PortForwarding
You will open a SSH connection to your server but a local port, lets say 4444, will connect over the SSH connection and resolve to 8888 on the remote server.
With this you'd be able to open a browser locally and go to localhost:4444 and it would resolve to your remote hosted site. The command for this locally would be something like -
ssh -L 4444:localhost:8080 yourremoteserveraddress
An alternative option would be to use a SOCKS proxy via dynamic forwarding but this would involve needing to reconfigure your browser.
Always keep in mind any company policies around this type of thing. Even though 22 and 443 are open to the internet, use of them in this manner may break a policy and there is always the possibility of the company using a MITM proxy to monitor for this type of usage, specifically on 443.
All connection attempts on RhodeCode on CentOS 6.3 are refused except from localhost.
Note that iptables is not running, and I am only trying to visit the web interface.
I have googled the exact error message below and looked around SO. I have yet to find a solution.
abort: error: No connection could be made because the target machine actively refused it
If the firewall is down, and I am not trying to modify any repository, what else is preventing me from connecting? EDIT: See #5 below. Not sure how to address it yet.
Things tried and other info
Using localhost, 127.0.0.1 and hostname in production.ini
service iptables stop
Connected over HTTP successfully. In other words, connections are accepted outside RhodeCode.
Made sure no authentication methods were enabled or configured in production.ini
Although the server accepts connections on localhost, netstat -l does not show that port 5000 is listening. Port 5000 is set in production.ini and ps uax | grep paster confirms the server is running. No other software tries to grab port 5000.
Ok, apparently I have been misunderstanding the host configuration. I was running on the assumption that host should be set to 127.0.0.1 or localhost in production.ini for RhodeCode to know what host to look for for another service. This was a faulty presumption on my part, since I am used to pointing web applications to local systems to look for databases.
It turns out that host binds the application to a specific address for access, meaning that it RhodeCode was supposed to only respond to local requests, regardless of what other system policies say. The setup docs did not make this clear because it did not specify that external connections would be refused. All it said was:
This command [paster serve] runs the RhodeCode server. The web app should be available at the 127.0.0.1:5000. This ip and port is configurable via the production.ini file created in previous step
The problem was fixed by binding RhodeCode to 0.0.0.0, which opened it to outside connections. Kudos to Łukasz Balcerzak for pointing this out in the RC support google group.
I have a web server running out of my home. I have assigned it an address such as 192.168.1.123 on port 80.
I understand that this is running on my local network. If I go to another computer on my network and type in the server's ip address, I can see the server.
Is there a way to access this server from outside my LAN?
Yes, you need to set your router to forward connections to port 80 to your internal IP address (192.168.1.123). Look for Port Forwarding on your router admin screen which I would imagine you access by going to http://192.168.1.1
Keep in mind that your ISP may block port 80 completely in which case you can run your web server on a different port (for example por 8180) and have your router forward connections to port 8180 to your internal IP.
To access your server from outside, you just need to point your browser to your external IP address which you can find out by going to http://www.ipchicken.com
Assuming you have a connection to the internet:
https://github.com/progrium/localtunnel
is a quick way to access your local server from the internet. There might be similar implementations in other languages/platforms. This is just the one I know about.
Remember that security issues need to be carefully considered when opening your local network to the world.
If you use a PHP Webserver you can set it this way:
php -S <YourIPAdresse>:<SomePortNumber> <StartPHPpage>
Example: „php -S 192.168.1.123:9000 index.php"