I can't connect to ContextBroker from another machine, even a machine in the same LAN.
Accessing by ssh without any problem
ssh geezar#192.168.1.115
and then
curl localhost:1026/statistics
the terminal shows the statistics, all right
<orion>
<xmlRequests>3</xmlRequests>
<jsonRequests>1</jsonRequests>
<updates>1</updates>
<versionRequests>1</versionRequests>
<statisticsRequests>2</statisticsRequests>
<uptime_in_secs>84973</uptime_in_secs>
<measuring_interval_in_secs>84973</measuring_interval_in_secs>
</orion>
But when I try without ssh connection...
curl 192.168.1.115:1026/statistics
curl: (7) Failed to connect to 192.168.1.115 port 1026: No route to host
Even, I routed the port 1026 to that machine (192.168.1.115) on the router configuration, and tried to access from my public IP, the result is the same, failed to connect
I think I am missing something, but.. what is it?
The most probable causes of this problem are:
Something in the host (e.g a firewall or security group) is blocking the incoming connection
Something in the client (e.g a firewall) is blocking the outcoming connection
There is some other network issue is causing the connection problem.
EDIT: in GNU/Linux system, iptables is usually used as firewall. It can be disabled typically running iptables -F.
Related
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.
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.
I have chosen QuteCom SIP client for windows to chat.I have installed and configured the account with my public server. My SIP server is kamailio.The connection to the server is not established. The application is connecting to the server for a long time.
Any help is appreciated.
If looks like keep connecting, then I guess the SIP messages don't get to the server.
You can install Wireshark to monitor traffic on windows host on port 5060 (the SIP port) in order to see if SIP messages are sent to the server.
On server, you can install ngrep for the purpose of seeing if traffic from the phone comes there. The command would be like:
ngrep -d any -qt -W byline port 5060
If you don't see traffic coming to the SIP server, then might be a firewall or an ALG between the client and the server, or, a firewall even on client host or server itself.
If it is something in between (not on client host or server), then you should try to use TCP or better TLS.
Note that if you have the firewall on the server, you will see the SIP packets coming on the network, but they will be dropped by the kernel before getting to application layer. Typically on Linux you can see the firewall rules with:
iptables -L
If the SIP packets come to the server, then set debug=3 in kamailio.cfg, restart kamailio and watch the syslog file (e.g., /var/log/syslog or /var/log/messgaes) for kamailio-specific debug messages -- you should get hints of what happens during processing.
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.
Socket Server with SSLStream some times refuses new connections from clients.
I used the telent hostname port, and it says Connecting To host...
Could not open connection to the host, on port 6002: Connect failed
I used netstat -a , and I see TCP status as
TCP 0.0.0.0:6002 host:0 LISTENING
I also see the service as listening in tcpview too.
The error I see on client side is connection refused with error code 10061.
The same socket server was accepting new connections and just runs fine without any issues.But after some time the above issue happens.its random.
When I restart the sockets it just works fine and accepts conenctions, which I don;t want to do it frequently.becasue this disconnects clients, who are already connected.
Could somebody help me to trouble shoot this?
Thanks.
Where are you running netstat? On the server?
Try connecting to the socket from localhost (from the server itself) using the destination IP address 127.0.0.1
Do the same test with the network IP of the server.
My guess is that the firewall is preventing external access or a router in between is preventing the connection.
It works for a while and then stops. Few options I can think of:
Some firewall on the way does some kind of throttling
You open and close too many connections too quickly. In this case you exhaust the ephemeral ports on the client (usually) and/or on the server. If you do netstat -a you will see a lot of sockets in TIME_WAIT state, try this both on client and server. Solution here is to reuse connections (best). Or increase the number of ephemeral ports (registry setting). But this will take you only so far.
You have a bug in your server and it stops accepting new connections after a while.