A port provides a location for an application to interface with the network. If there is no application that is listening at a particular point, data sent there will never be used.

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111
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1answer
183k views

What is port forwarding and what is it used for?

There are a lot of questions on 'port forwarding' but there doesn't seem to be one that clearly states what it is and what it's used for. So: What is Port Forwarding? What is it used for, and why ...
87
votes
3answers
71k views

Finding the process that is using a certain port in Linux

I'd like to be able to find out which process is currently using a certain port in Linux. Is there any way to do this?
25
votes
4answers
95k views

PID:4 using Port 80

I was trying to install Zend Server CE on my computer but when I got to the point were I need to choose the port for my Web Server it says: "Web Server Port: 80 Occupied". So I decided to check what ...
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2answers
10k views

Block all ports except SSH/HTTP in ipchains and iptables

How can I block all ports except ssh (port 22) httpd (port 80) using iptables and iphains?
16
votes
7answers
53k views

Apache Server on Windows 7 opening up ports?

I have installed Apache 2.2.14 on Windows 7 and can view my web pages using both http://localhost and http://127.0.0.1 but when I try to access the server from another computer on the same router, it ...
98
votes
2answers
199k views

What are CLOSE_WAIT and TIME_WAIT states?

When I do netstat -a on my Windows machine, I get a listing of the ports with one of the four states: LISTENING CLOSE_WAIT TIME_WAIT ESTABLISHED What do CLOSE_WAIT and TIME_WAIT mean/indicate?
10
votes
3answers
26k views

Find out what program runs in the java.exe process

I have a problem: always when my computer starts, there is a java.exe process listening in the port 7676. I want to find out what it is to be able to delete it. Is there any way that I can find that ...
5
votes
7answers
3k views

Dos and/or Windows versions of Unix SCRIPT command

Back in university, when we had to submit an assignment in CS, we would have to perform a series of steps including running script, date, whoami, etc., and then running our program. The script ...
4
votes
1answer
8k views

How can I map a domain name to an IP address and port?

I want to give a domain name to the IP address and port for an application in Windows 7. For example, test.com should map to 127.0.0.1:59873. Is there anyway that we can do it by using a web server ...
9
votes
5answers
826 views

What ports are used by an application [duplicate]

I'm testing an application which opens its own ports (acts as a server for these ports, hence listens at that ports) and where the same application connects to ports bound by other applications (acts ...
9
votes
5answers
70k views

How do I find out what service is using a certain port?

Port 22 specifically. I installed freeSSHd on a Windows Server 2008 box that only runs IIS. When I try to start the SSH Service, it tells me that the port is already being used. How can I find out ...
4
votes
2answers
5k views

Detect what outgoing ports are bypassed by firewall

My school has a firewall which limits most outgoing ports. There're only TCP/80, TCP/443, TCP/21 allowed. Is there's a way to find out all the outgoing port allowed by the firewall? My current idea: ...
-1
votes
5answers
4k views

Why do I see router and not my real IIS?

I am trying to access IIS through web but unable to do so. Basically I have a router (which functions as router and modem) that is given by ISP and I have another router connected to the router given ...
7
votes
3answers
45k views

How to know which port is busy or free on Windows 7? [duplicate]

Possible Duplicate: How can I see all active connections? I have some conflict of ports and my WampServer didn't work, so I have to know which port is used. Is there a command line command ...
6
votes
2answers
4k views

Why is there electricity flowing through my VGA and other ports?

I am using Windows 7 on a Sony VAIO laptop. When I connected my PC to the charger, I felt a little electric shock when I touched the VGA and other ports. I tested with a current detector and found ...
3
votes
3answers
11k views

How to open ports on router for better torrent performance

I've been using utorrent to download and upload torrents for a long time. Recently someone told me that I need to open port(s) for utorrent from my router settings for better downloading and uploading ...
3
votes
1answer
616 views

What is the name of this laptop port?

Laptop is Acer TravelMate 331T.
3
votes
2answers
2k views

How can I plug my LPT printer into a motherboard with no parallel port?

I have a new computer with a Asus P5QL Pro motherboard and wanted to plug my old HP DeskJet 950C printer into it only to discover that the motherboard has no LPT/Parallel port. What is the best ...
1
vote
1answer
2k views

TCP/UDP ports that cannot be bound (permission error), but don't show up in netstat

When attempting to listen on certain TCP or UDP ports, I get weird error messages regarding permissions (or generic messages, depending on the program used to bind). The message in German is "Der ...
0
votes
5answers
486 views

iTunes ported for Linux?

Is there any ported version of iTunes for Linux? Really would like it; i need to restore my iPod. Emulation is slow because i have here a 1 GB of RAM.
11
votes
4answers
67k views

How can I check which ports are busy and which ports are free on my Linux machine?

Is there any command line command or any other way to find and list out the busy and free port numbers on my Linux machine?
11
votes
2answers
17k views

No idea what is listening on port 80 in OS X

I'm on OSX Mountain Lion 10.8.3, and I've freshly rebooted my Mac. I want to start a service (like Apache on port 80), but there is already something going on with port 80: telnet localhost 80 ...
7
votes
1answer
13k views

Why does google chrome need so many ports open?

I just did a port check with CPorts and I find that google chrome has so many local ports open in the range of 7713 - 7794. They are all connects to 80 or 443 on the other end. Why does google ...
6
votes
1answer
8k views

Difference between port mapped and memory mapped access?

Can anyone explain what's the difference between port mapping and memory mapping, and what having both accomplishes? Why is there port mapped, how does it differ in structure from memory maps, and is ...
2
votes
1answer
6k views

How to connect with Pidgin to Facebook-chat and Google Talk when XMPP port 5222 is blocked?

I have not been able to google this straightforwardly, so here it goes for others. Many networks have firewalls that block all but the basic ports. I am on one of them but I still want to acces gtalk ...
10
votes
1answer
1k views

268 Ports Associated with Chrome

I'm currently using a Windows box, running Chrome 27 on the dev channel, and I have what I believe to be an unusually large number of listening connections connected with the process. The following ...
9
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1answer
2k views

How do I make Skype not use port 80?

I need this port for apache, how do I forbidden Skype from trying to use this port any more?
7
votes
8answers
99k views

How to “restart/repair” an USB port?

My laptop has two USB ports, but one is broken, so I use a USB hub in the other good USB port. In that USB hub, I use a mouse and keyboard. Suddenly, that USB port doesn't detect the mouse and the ...
11
votes
8answers
32k views

Utility to open TCP port to listen state

Is there some basic utility to open a specific network TCP port on my machine? I need to test how my program deals with ports on listening state..
8
votes
4answers
11k views

Why is System listening on port 8000?

I noticed by accident today that I have some unknown webserver listening on port 8000. Opening http://localhost:8000 just returns 404, so I don’t get any hint what exactly is listening there. I’ve ...
7
votes
4answers
42k views

USB Ports Not Working

None of the USB ports work anymore on my HP EliteBook 2540p laptop which is running Windows 7 Pro SP1. By "not working," I mean if I try plugging in a thumbdrive or external HDD it does nothing ...
6
votes
1answer
265 views

what port is this [duplicate]

I've not seen this port before, it looks kind of like a HDMI port and has this symbol next to it... what is it? It's on the back panel of a desktop computer.
5
votes
5answers
16k views

how to disable feature that opened port 445 on windows server?

I'm trying to disable services that I do not need, to improve latency and improve security. I found that port 445 is still open by doing telnet on localhost and port 445. As I do not need port 445, I ...
4
votes
1answer
2k views

What is the purpose of ports?

I have a few questions in regard to the following explanation of ports I found. The Application layer talks to the Transport layer through a port. Ports are numbered and standard ...
4
votes
2answers
559 views

Weird hits on port 2703

I'm getting these periodical console messages on my Mac: 7/22/11 8:01:03.925 AM Firewall: Stealth Mode connection attempt to UDP 10.0.0.1:2703 from 91.143.232.133:15881 7/22/11 8:01:05.885 AM ...
3
votes
1answer
6k views

How can I effectively block torrenting?

My WNR1000v3 is serving six people and two of them have decided that despite my warnings they're going to torrent heavily all day. Not dealing with that crap I decided to reserve their IPs and set up ...
1
vote
1answer
78 views

How do I find out what services are bound to a port number?

Given a TCP/UDP port number, how do I find out the name of the service bound to that port? I want to do this on various flavours of Unix. Mostly Gnu/Linux (usually Debian) and Mac OS X.
1
vote
1answer
669 views

USB hub assigning random com ports when Windows 7 PC or USB Hub are rebooted

I have four hardware devices that are plugged in through a self powered USB hub. Currently the devices are assigned COM1 COM2 COM3 COM4 through device manager as hoped. However, when rebooting the ...
1
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3answers
5k views

better tool than netstat

OS: Windows server/ Windows XP Is there any port scan tool that can do what netstat does and also has a filter feature, so that unnecessary connections can be hidden?
11
votes
5answers
5k views

What is ::: in the Local Address of netstat output?

This is the output of netstat -tulpn that I get: tcp 0 0 127.0.0.1:2208 0.0.0.0:* LISTEN 2055/hpiod tcp 0 0 127.0.0.1:631 ...
9
votes
6answers
7k views

Port scan revealed port 1111 open. What is it?

I am new to systems administration and have a new server running a website with http (at port 80), https (at port 443) and ssh (at port 22). I did an nmap port scan using my personal laptop and other ...
5
votes
2answers
2k views

Will cases with front USB port support USB 3.0?

If a computer case has a USB port in the front, will it support USB 3.0 if my motherboard supports it? Or does the case vendor need to specifically mention USB 3 support? (BTW, I haven't seen such ...
4
votes
1answer
5k views

What is the difference between Port and Connector?

I want to know the difference between Port and Connector in Computer (the physical ones),and how can i tell that this thing is a port or connector ? I know that both terms are used for the same ...
3
votes
3answers
2k views

What is this port/connector on my laptop?

I have this port on my laptop and I have no idea what is it used for. It's not even listen in the laptop technical specifications. The laptop is a HP Pavillion dv5-1101en. Here is a larger image ...
2
votes
1answer
230 views

If my DSL modem leaves a port open, how vulnerable is my router?

Port scans of my old Netgear router showed that port 4567 was open. I assumed my router was to blame. Now port scans of my new Linksys router show the same open port, which makes me think my DSL modem ...
2
votes
3answers
746 views

Is the same port acting as both client and server?

i find something strange in this netstat output. the output is taken using netstat -a -n -o -p TCP command on win 7. Proto Local Address Foreign Address State PID TCP ...
2
votes
0answers
2k views

Why do I see router and not my real IIS? [duplicate]

I am trying to access IIS through web but unable to do so. Basically I have a router (which functions as router and modem) that is given by ISP and I have another router connected to the router given ...
1
vote
1answer
282 views

Why won't apache bind to port 80 on Windows 10 upgrade

I just upgraded to Windows 10 and now Apache won’t start complaining that port 80 is in use. NetStat -a -b Says that it can’t figure out what process is using port 80. How do I find out and kill ...
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3answers
5k views

How to remove IIS for WampSERVER?

I have WampServer installed, and I installed Microsoft SEO Toolkit, I guess that has the IIS dependency. And I guess the iis service uses port 80. Now every time I start WampServer, I need to go to ...
1
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1answer
1k views

Forwarding The Same Port To Multiple LAN Servers?

I would like to be able to use the Wake-On-LAN feature to be able to turn on the two computers attached to my router when i am out of the house using my WAN IP Address. Router = 81.210.109.0 PC A = ...