Questions tagged [port]
Port is a generic term that can refer to port number (software related term), and computer hardware port. Here, questions referencing this tag refer to port numbers.
1,698
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Check if port is open or closed on a Linux server?
How can I check if a port is listening on a Linux server?
- 3,177
148
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8
answers
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What port should I open to allow remote desktop?
What port(s) should I open/NAT to allow me to use Remote Desktop?
126
votes
4
answers
1.0m
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How to check if a port is blocked on a Windows machine?
On the Windows platform, what native options to I have to check if a port (3306, for example) on my local machine (as in localhost), is being blocked?
- 1,373
120
votes
1
answer
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What ports to open for mail server?
I have just finished setting up a Postfix mail server on a linux (ubuntu) platform. I have it sending and receiving email and it is not an open relay. It also supports secure smtp and imap.
Now this ...
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119
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What firewall ports need to be open to allow access to external git repositories?
What firewall port(s) need to be open to allow access to external git repositories?
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118
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2
answers
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Why does the MySQL command line tool ignore the --port parameter?
This is what I'm doing:
mysql --host=localhost --port=9999 mysql -u root -p --execute="show tables;"
The command works (connecting to port 3306) no matter what I provide in --port argument. I have ...
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99
votes
3
answers
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How do high traffic sites service more than 65535 TCP connections?
If there is a limit on the number of ports one machine can have and a socket can only bind to an unused port number, how do servers experiencing extremely high amounts (more than the max port number) ...
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96
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4
answers
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What is the maximum port number in Linux?
I'd like to set some Linux services to non-standard ports - what's the highest valid port number?
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90
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6
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How do you free up a port being held open by dead process?
A colleague of mine recently ran into a problem where a process that had supposedly died was still bound to a network port, preventing other processes from binding to that port. Specifically, netstat ...
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83
votes
10
answers
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How to check what port mysql is running on
On my windows dev box mysql is running on port 3306
How can I check what port it is running on the unix server that I have to upload the app to.
- 2,379
75
votes
12
answers
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Does changing default port number actually increase security? [closed]
I have seen advice saying you should use different port numbers for private applications (e.g. intranet, private database, anything that no outsider will use).
I am not entirely convinced that can ...
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74
votes
16
answers
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Why Block Port 22 Outbound?
I'm a programmer, and I have worked for a few clients whose networks block outgoing connections on port 22. Considering that programmers often need to use port 22 for ssh, this seems like a ...
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70
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8
answers
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How to check if a port is open for remote system(ubuntu) [closed]
Is it possible to check that if the ports are open for the remote system on ubuntu server?
I should able to check if a port(eg:ssh) on my machine is open for the remote machine.
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56
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11
answers
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Is there an equivalent to ssh-copy-id for Windows?
Is there any equivalent or port of ssh-copy-id available for Windows? That is, is there an easy way to transfer SSH keys from a local machine to a remote server under Windows?
In case it helps, I'm ...
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53
votes
4
answers
70k
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Bind to ports less than 1024 without root access [duplicate]
I would like to run applications I'm working on that binds to port numbers less than 1000 without requiring root access.
I'm using Linux Mint and have root access to set it up. I would ideally like ...
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53
votes
1
answer
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nginx: no permission to bind port 8090 but it binds to 80 and 8080
I'm struggling with some strange permission related behavior: when I configure nginx to listen to port 8080 everything works as expected, but when I use any other port I get something like
2014/01/10 ...
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45
votes
1
answer
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How do I tell what is running on which ports in Ubuntu?
How could I tell what is listening on which ports on Ubuntu? In other words, how do I get a list of ports that are in use?
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1
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Declaring multiple ports for the same VirtualHosts
Declare multiple ports for the same VirtualHosts:
SSLStrictSNIVHostCheck off
# Apache setup which will listen for and accept SSL connections on port 443.
Listen 443
# Listen for virtual host requests ...
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38
votes
7
answers
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netstat shows a listening port with no pid but lsof does not
This question is similar to Network port open, but no process attached?
I've tried everything from there, reviewed the logs, etc... and can't find anything.
My netstat shows a TCP listening port and ...
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35
votes
7
answers
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What firewall ports do I need to open when using FTPS?
I need to access an FTPS server (vsftpd) on a vendor's site. The vendor has a firewall in front of the ftps server. I have a firewall in front of my FTPS client.
I understand that ports 990, 991 and ...
user3293
34
votes
3
answers
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How do I create Virtual Hosts for Different Ports on Apache? [closed]
I want apache to do this >
mydomain.com:80 --- opens var/www1
mydomain.com:81 --- opens var/ww2
mydomain.com:82 --- opens var/www3
Problem is I don't know if those ports are open on Linux (how ...
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30
votes
1
answer
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Selecting Interface for SSH Port Forwarding
I have a server that we'll call hub-server.tld with three IP addresses 100.200.130.121, 100.200.130.122, and 100.200.130.123. I have three different machines that are behind a firewall, but I want to ...
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29
votes
2
answers
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check port open without telnet [closed]
What do people use when Telnet is not installed to check a port is open and reachable? E.g. I used to use the technique of telnet <destination> and know it was there, even if telnet could not ...
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28
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10
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How do I find out whether a port is available on Ubuntu 8.04?
Is there any command I can run from bash that will tell me whether a port is already open?
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6
answers
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Determining PostgreSQL's port
I know that by default PostgreSQL listens on port 5432, but what is the command to actually determine PostgreSQL's port?
Configuration: Ubuntu 9.10 with PostgreSQL 8.4
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28
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9
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How do I get rid of sockets in FIN_WAIT1 state?
I have a port that is blocked by a process I needed to kill. (a little telnet daemon that crashed).
The process was killed successfully but the port is still in a 'FIN_WAIT1' state. It doesn't come ...
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27
votes
4
answers
125k
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How do I see if a port is in use on a windows machine?
I am using Windows XP pro, and I need to know if something is registered on a port.
If so how can I tell what is on the port?
EDIT
What I mean by registered is that I am trying to test a .NET ...
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27
votes
11
answers
379k
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How can I find out if a port is opened or not?
I have installed Apache server on my Windows 7 computer. I was able to display the default index.php by typing http://localhost/ in the address line of my browser.
However, I am still unable to see ...
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26
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5
answers
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How to remove access to a port using firewall on Centos7?
Had a port opened up to for public use using firewall-cmd, I wanted to limit this port to a specific IP which I found the answer for on this SITE.
I used the following to open it:
$ firewall-cmd --...
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1
answer
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How do I specify port number for PuTTY to use with Windows cmd?
I start most of my SSH connections with a windows command like this
cmd://"C:\Program Files\PuTTY\putty.exe" -ssh [email protected]
I assume this defaults to port 22. Now I need to connect on a ...
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25
votes
2
answers
150k
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Opening up port 8080 in CentOS
I'm new to opening up ports in CentOS. I need to open up tcp port 8080 and have installed/ran nmap to find it is not open already. I've been reading about the iptables command, I have v1.3.5 installed ...
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25
votes
4
answers
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Change protocol associated with port in wireshark
I'm trying to monitor some web traffic using wireshark. Our web proxy is on port 9191. How can I get the wireshark view to treat port 9191 just like port 80 - ie as HTTP.
Just using Decode_As on the ...
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1
answer
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Why Are There Only 65,535 Ports, and Will We Ever Have More? [closed]
I understand the original reasoning behind having 65,535 ports per IP address: this is the highest number that can be represented by a 16-bit, or 2-byte, number, and it wasn't conceivable that ...
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22
votes
5
answers
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Prevent port change on redirect in nginx
I currently have nginx setup to serve content through Varnish. Nginx listens on port 8000 and varnish connects users' requests from 80 to 8000.
The problem is, on some occasions, particularly when ...
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22
votes
3
answers
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Node.js is not accessible from external IPs on Ubuntu
I'm sure this is very noobish, so forgive me.
I'm trying to run a node.js server on port 8080 of my ubuntu 10.04.
Here's the result of iptables -L on the server:
Chain INPUT (policy ACCEPT)
target ...
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22
votes
12
answers
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FTP hangs on: 150 Opening ASCII mode data connection
I am setting up an FTP server on my Windows 2008 server (R2).
Everything appears to be installed correctly but I am having trouble using an FTP Client to login to my FTP server.
I can remote desktop ...
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22
votes
2
answers
35k
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On Linux, how can I tell how many ephemeral ports are left available?
Is there a method in Linux to check how many ephemeral ports are left available? I occasionally see "Address already in use" errors as a result of running out of ephemeral ports. A machine reboot will ...
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21
votes
3
answers
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How to assign a hostname to SSH tunnel
I'm using
ssh [email protected] -g -L 4321:localhost:28017
to establish a tunnel from my MacBook to my dedicated server at my hosting provider. It works well. Now I want to access several admin sites ...
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20
votes
9
answers
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How to find the number of open ports in linux?
How to find the number of open ports in linux? I want to see if I am running out of ports. Also, how do I see the limit of my OS?
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2
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SElinux error :ValueError: Port tcp/5000 already defined
I have been trying to add an exception to SELinux for apache on port 5000.So I used the command:
# semanage port -a -t http_port_t -p tcp 5000
But returns the error,
ValueError: Port tcp/5000 ...
19
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5
answers
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Understanding Ports: How do multiple browser tabs communicate at the same time? [closed]
I realized today that I fundamentally don't understand how port communication works.
If I fire up an instance of a webserver listening on port 80, it can respond to many requests from many different ...
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18
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9
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Disable TeamViewer from "stealing" Port 80?
How can you disable TeamViewer from using/reserving port 80? I am certain in the previous version <v4.1.6 there used to be a radio button option in "options" which disabled it from needing it, but ...
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6
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Cannot access port 80 from remote location but works on local?
I have a linux server on configuration with apache. However I cannot get access to it using a remote computer.
I can ssh to the server normally.
my IP table:
Chain INPUT (policy ACCEPT)
target ...
- 1,511
18
votes
3
answers
168k
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how to forward dns alias to hostname:port? [duplicate]
Possible Duplicate:
How to use DNS to redirect domain to specific port on my server
My web application is running on myserver.mydomain:10000
I would like to make it available on the intranet as ...
- 1,169
17
votes
5
answers
4k
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Preventing other applications from binding to port 80 and 443
Last week I got a call from a scared customer because he thought his website was hacked. When I looked up his website I saw the apache2 default page. That night my server (Ubuntu 16.04 LTS) had ...
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votes
10
answers
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Port 80 is being used by SYSTEM (PID 4), what is that?
I am trying to use port 80 for my application server, but when I perform "netstat -aon" I get
TCP 0.0.0.0:80 0.0.0.0:0 LISTENING 4
When I look up the process in ...
GiH
17
votes
3
answers
31k
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What is the best way to measure latency via a "telnet to port" test, preferably with built-in Linux tools?
I'm writing a Graphite/Diamond collector measuring network latency. Specifically it should measure the time it takes to open up a connection to a port on a remote server. And it needs to work via ...
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16
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2
answers
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Determine process using a port, without sudo
I'd like to find out which process (in particular, the process id) is using a given port. The one catch is, I don't want to use sudo, nor am I logged in as root. The processes I want this to work for ...
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16
votes
1
answer
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Failed to connect to 127.0.0.1 port 80
I have running nginx server (doesn't matter which server):
$ sudo netstat -tulpn | grep 80
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 4268/nginx
tcp6 0 0 :::80 ...
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15
votes
2
answers
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Linux networking port exhaustion
I've done as much research as I could on this without digging right off in the kernel source. There seems to be a large amount of disinformation/incorrect info on the subject, so I hope this answers ...
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