Can anybody help me with using nmap? I don't quite get it when it comes to find out which port a specific server is running on.
To exemplify my issue, I have to install the apache2 web server on an Ubuntu OS. Then, I have to start its daemon (no problem, I simply ran "service apache2 start", which, I think, really did the job for me). Now, I just have to figure out on which port this service is running. I read about netstat and nmap, but I don't really know which parameters I should use in order to find out the port. So, my question is : Is there any way to find out the port this service is using? If yes, how could I do that?
Furthermore, if I wanna find out which ports are opened (in "established" or "listening" state) on a specific server, how should I proceed to find out?
Thanks very much in advance.
netstat -tlp does what you ask for. nmap would work (e.g. nmap -n localhost), but why scanning ports if you just can ask the system?
Related
at my firm we have a jupyterhub/lab installed and is used by roughly 70-100 people in a secure network that can only be accessed to from work. Recently the idea of hosting web-applications for short time use came up, but we are having port problems. User A is running a web application on port 5000, and User B can’t use the port because it is already in use. Port 5000 is default, it can be changed but this is not the behavior we want. Does anyone know of a way for web-applications to run on the same port in the same environment? Have looked into server-proxy but i do not really understand it. Is the way to achieve this really to be running a vm for each user securing that the port is not in use?
Any help is appreciated
Could anyone shed some light on this? I have watched a few YouTube videos with the same problem but all solutions are based on Windows. How could I fix this on a Mac? I'm pretty sure I have no other servers running.
Thanks
see error image from netbeans
This means that there is another application using the ports the Glassfish requires. Use the command
lsof -nP -iTCP:$PORT | grep LISTEN
to list the what ports are in use along with the process ID of the process using the port. Glassfish requires ports 4848, 8080 and 8081 to be free. One app that sometimes causes port issues is vnc, so check if you have screen sharing turned on and try disable it if that is the case.
I am getting this error while I am trying to run java web program in my netbeansenter image description here.
Can anyone please help?
How to solve this problem?
Since the port 198 is being, used you either need to use a different port, or stop the program using that port. Use some sort of port scan to find out what program is using the port and resolve it from there. It says to check the server logs, and it is also possible that you are trying to run multiple instances of your program.
I'm developing Firefox addon that communicate with external program by sockets. This program create local socket server on specified port when this addon need it. I would like to ckeck from this addon whether this application has opened this port already.
On Win7 when server isn't created yet I receive in socket created by addon NS_ERROR_CONNECTION_REFUSED in nsIRequestObserver::onStopRequest but if I can feel certain port isn't open when I receive this error?
You try to connect and see if the connection succeeds.
If it doesn't, then the port is not reachable (open).
That's the most obvious and easiest answer.
Other low-level solutions would require polling the OS itself somehow. That would be cross platform specific (so you'd need to write an implementation per platform) and also there is no API readily available so you'd have to mess around with C/C++ or at least js-ctypes, or hack together some ugly "execute this program and check output" stuff. All of which doesn't worth the fuzz.
If you want to find out which "inbound ports" are in use in windows you can use cmd,
if you don't know how to open cmd - open the run dialog by pressing windows-key+r. type cmd and hit enter
type netstat -a and hit enter and it will list all "listening" ports.
more info - http://www.techrepublic.com/blog/it-security/list-open-ports-and-listening-services/
On beforehand I have to say i'm a bit of a newbie.
I've sucscribed to a VPS with Ubuntu 11.04 server, I installed Jboss and am starting it with the -b 0.0.0.0 option.
Now if I lookup the address ip:8080 on a browser on the VPS itself it's working fine, but if I try to look it up on a browser on an external machine it isn't able to access the page.
I tried to modify the hosts file but without success. Maybe its the iptables? Or something else?
I really appreciate any help thanks.
Take the static IP of the server, ping that from your command line tool with ping. If you are successful in pinging the server you are all set. Now go to the browser of the external pc and type the static ip and give the port as 8080. It will certainly work.
Some good suggestion from my side is, try PaaS(platform as a service) now as that is much easier than VPS and you will get up and running in minutes. Try Jelastic. It has got JBoss hosting. Deploy your WAR file there and you can access it immediately. Ket me know if you really go ahead and use it.
Surya