Unable to launch the asp.net development server because port '80' is in use

Question

I need to use port 80 for my development server. Before i restart pc, it's still working fine. After that, it pop up the port 80 is in use. The development server able to run if i changed to other port.

I've checked using netstat -ano, no program is using it (my iis is using other port and my skype is not using port 80 as well). I also test with telnet localhost 80, it didnt show any failure message, just the screen goes blank...I'm using win xp. Is my visual studio has problem?

Answer 1

I had the same issue when trying to add a service reference to one of my projects. I deleted the service's site from my local IIS and re-created it from the service project in Visual Studio and re-built. This resolved the issue for me.

Answer 2

I also faced this issue and got two solutions for this:

• There is already a question and this solution.

• What I tried is to change the port. For example: I was getting an error for port 22116, so I changed the port to 22117 and it started working.

Now how to do that:

1. In Solution Explorer, right click the name of the application.
2. Click on Properties menu.
3. In the left pan, click on the tab - Web
4. Here you can see a check box "Specific port" . (I just changed from 22116 to 22117)

For me, after this change it started working.

Answer 3

If you use Skype, then Skype reserves port 80 as an alternative port (disable in Skype settings). I had this happening to me several times.

Answer 4

Things i have done.

1. Check it with netstat -ano and TcpView, both did not show port 80 is in use.
2. Try to connect it via telnet (telnet localhost 80). The screen goes blank, but when i press any key, the screen back to command prompt. As Lerxst said, screen goes blank meaning the port is occupied but i can't find any program is listening it.
3. I have skype installed, but it has turned off using port 80.
4. I have SQL 2008 installed, but i has turned off Integration & Reporting Services which may use port 80.
5. Changed my iis default port number to 8888 and even turn off the service.
6. I have XAMPP installed but i have turned off it.
7. I tried to turn off firewall as well, but still the same.

Answer 5

If your telnet window goes blank when you telnet to 80, then something is already listening on that port.

Answer 6

Port 80 is a reserved port number, for HTTP traffic. http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers

Why exactly do you need to use port 80?