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.

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5
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1answer
785 views

Is it bad practice to run a web application server directly on port 80/443

I am hosting a web app on amazon aws, using an ec2 instance. On that instance i will be running only one application. using glassfish v3.0.1 I do not want to run the app using : ...
9
votes
6answers
6k views

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 ...
28
votes
16answers
28k views

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 ...
43
votes
11answers
6k views

Does changing default port number actually increase security?

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 ...
29
votes
4answers
10k views

Bind to ports less than 1024 without root access

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 ...
17
votes
6answers
88k views

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 and I have a firewall in front of my ftps client. I understand that ports 990, 991 ...
15
votes
1answer
24k views

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 ...
3
votes
3answers
4k views

How to assign a hostname to SSH tunnel

I'm using ssh root@my.server.ip -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 ...
5
votes
1answer
998 views

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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8answers
6k views

Used/blocked ports in Ubuntu

starting up Glassfish AS would tell me the port 4848 is blocked (or any port that I configure). But checking the ports are not used. There is no firewall. root@ubuntu:~/glassfishv3/glassfish/bin# ...
4
votes
6answers
8k views

Regular user using ports below 1024 [duplicate]

Is there a way on Linux (CentOS if that matters) to enable regular users to use ports below 1024? (open listening TCP socket on that port) Currently I understand that only root has privileges to use ...
1
vote
3answers
454 views

Server Firewall preventing sending of email

The firewall on my VPS appears to be preventing my site from sending email. It was working fine until the end of last month. My hosting provider (Webfusion) has been next to useless. I am able to ...
5
votes
4answers
2k views

How to make a URL point to a Tomcat instance?

Sorry if this question makes no sense (no expert here), but I understand that tomcat listens to port 8080 and that url are usually addressed to 80. Is there a way to tell DNS that urls should point to ...
5
votes
4answers
628 views

Why was the FTP protocol designed to use more than one port?

The question is in the title. The reason I wonder this is because I'm coding an tcp service and would like to explore some of the reasons as they may shed some light on my work.
3
votes
3answers
1k views

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) ...
2
votes
2answers
321 views

Restrict User Access to Certain Ports

This question is purely hypothetical. Is it possible to restrict which ports certain users may use for their processes? Say users1 gets ports 8000-8999 and user2 gets ports 9000-9999. I am running ...
3
votes
4answers
155 views

Linking Domain Names to Port Numbers

I have a [game] server (CentOS) that has about 10 used ports. For one game in particular, I have 2 servers: a private one and a public one. The IP for them is the same, so to differentuate between ...
1
vote
3answers
801 views

Securing phpmyadmin: non-standard port + https

Trying to secure phpmyadmin, we already did the following: Cookie Auth login firewall off tcp port 3306. running on non-standard port Now we would like to implement https... but how could it work ...
1
vote
3answers
149 views

IP tables - changes not persisting

I've tried to open port 8605 on my server (used for socket connections) using: iptables -I INPUT 2 -s 0/0 -p tcp --dport 8605 -j ACCEPT However the change is not persisting, the port closes itself ...
0
votes
1answer
189 views

SQL server port is blocked on client machine

I have a client machine on which sql server is installed. This machine is using the internet though a proxy machine. On the proxy machine wingate is installed. I could not connect to the remote sql ...
0
votes
0answers
665 views

changing ssh port. Useful?

i will buy a dedicated server soon. I would like to know if changing the default port of ssh may be useful for security or it's completly useless. And if it's useful which ports range should I change ...
-2
votes
4answers
427 views

DNS record, paths and port [duplicate]

Possible Duplicate: How to use DNS to redirect domain to specific port on my web server I have a domain xyz.com and a web application running at http://AAA.BBB.CCC.DDD:8080/pcc. When the ...
43
votes
5answers
287k views

How to check if a port is blocked on Windows?

What is the easiest way to check if port 3306 on my localhost is being blocked?
6
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3answers
2k views

Debian - Port 80 is blocked, but I don't know by what

I can't make lighttpd listen to port 80. ~# /etc/init.d/lighttpd start Starting web server: lighttpd2013-03-16 23:15:02: (network.c.379) can't bind to port: 80 Address already in use failed! ...
15
votes
4answers
6k views

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 ...
11
votes
4answers
12k views

How to allow non-root user to listen on privileged port?

I want syslog to run as a non-root user on my linux box. That makes it impossible for it to bind to port 514 - because that's a privileged port. Is there any way I can grant non-admin user "foo" the ...
2
votes
2answers
1k views

socat connect-connect “proxy” two inbound TCP connections to expose a firewalled service?

I'm struggling a bit trying to see how to use socat (or a similar TCP port redirector) to expose a firewalled service on a PC. Here's the scenario: I have a server PC which will be acting as a ...
6
votes
1answer
10k views

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 ...
4
votes
6answers
7k views

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
3
votes
4answers
5k views

outbound ports that are always open

What are some ports that can NEVER be blocked outbound in firewalls, as doing so will stop basic internet use? Some I can think of are: port 53 udp/tcp -- dns, blocking this will prevent users ...
1
vote
1answer
1k views

Block SSH access from specific countries

I found this handy script online, and would like to modify it to only block SSH access but I don't know anything about iptables and Im afraid Ill kill my system as i have no physical access to it. ...
1
vote
0answers
7k views

Cannot telnet to SQL Server on port 1433

I've been working solidly on this issue for the past three weeks. I cannot seem to find where the actual issue is. I just recently found this article on how to troubleshoot the connection. I made it ...
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3answers
4k views

Debian Open port 81

I install lighttpd in one server using port 81. The problem is that the port is closed, and I don't know how to open the port. Regards, Pedro
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4answers
12k views

FTP/SSL in passive mode with portrange, which ports has to be open on the firewall?

We have to use FTP over SSL on our server and use a portrange with 5 ports for the data connection. A firewall is between client and server. We have to know what we have to open at the firewall: port, ...
0
votes
4answers
2k views

What firewall rules should be used for a home based system [closed]

I'm just setting up a home wireless network with connection to the internet. The router has settings to configure the firewall rules. Currently it's set to INBOUND ALL ANY and OUTBOUND ALL ANY. ...
4
votes
2answers
7k views

Should I use TCP or UDP to run a web server

I have just installed Apache web server on my computer. I have managed to use it locally (I can open index.php from my computer using my web browser). But I would like to make my web site available ...
3
votes
2answers
404 views

Is my linux firewall secure?

I am newbie to linux firewalls and trying to setup my systems firewall for a public facing computer. Here are my requirements: Ports 80 and 22 should be open for HTTP requests and SSH logins Since ...
3
votes
3answers
627 views

Use default options when compiling ports

I am compiling a few ports on FreeBSD, however during the compiling process I am often greeted with options for the dependencies of the port. This causes the compiling process to pause until I select ...
3
votes
3answers
759 views

Directing DNS to different ports

Greetings all, I have a server with two tomcat services (one being run on port 80, the other 8080). What I'm wanting to achieve is to have two different DNS records for these two ports, so they'll ...
2
votes
4answers
1k views

Using SELinux to force Linux to allow programs to bind to port numbers lower than 1024

Is there a way in SELinux to force linux to allow a program to be able to bind to a port number lower than 1024.
1
vote
1answer
132 views

Directory Listing (ls) error ONLY in port 22 (SFTP)

Using SFTP I suddenly get this result: Status: Connecting to 64.207.146.82... Response: fzSftp started Command: open "root@64.207.146.82" 22 Command: Pass: ********* Status: Connected to ...
1
vote
1answer
3k views

iptables has port 80 open but nmap shows it closed

I'm having some troubles getting a Debian webserver to open up port 80 for HTTP traffic. In my iptables, I opened up port 80 using the following commands: iptables -A INPUT -p tcp --dport 80 -j ...
1
vote
1answer
938 views

How do you run Nginx on port 8080 and Apache on port 80 on the same box?

I want to install Node.js on my box (CentOS 5) for testing and sandboxing but I can't uninstall Apache as recommend by developers using Nginx. So what I'd like to do is have Nginx serving ...
1
vote
1answer
227 views

What service uses UDP port 60059?

I received an email from logcheck that contained a number of attempted connections to UDP port 60059. This email is sent by logcheck. If you no longer wish to receive such mail, you can either ...
1
vote
4answers
2k views

Nginx + uWSGI on a fresh Ubuntu install - bind error port 80

I know this is a common problem usually having to do with apache or another service already running on port 80 and I have done a lot of searching and running netstat and still have not figured out why ...
0
votes
1answer
112 views

How do I block all access to machine except port 3389 using Open vSwitch

I can allow access to the machine and block everything else using: ovs-ofctl add-flow xenbr0 "dl_src={mac-address} priority=39000 dl_type=0x0800 nw_dst={ip-address} idle_timeout=65000 action=normal" ...
0
votes
1answer
117 views

How to route specific IPv6 address & port to another port?

I just got a VPS with an IPv4 address as well as a bunch of IPv6 addresses configured and I'm new to routing in Ubuntu/Linux. I would like to route requests with a specific IPv6 and port (i.e. port ...
0
votes
2answers
223 views

Is an Apache use TCP port on each connection?

Our system admin said "Apache use a TCP port on each connection" so A server can serve 65534 (MAX) simultaneously. is it Right? I think Apache use only 80 or 443. But , he use many file descriptor ...
0
votes
2answers
838 views

Solution to configure a NAS's FTP through blocked ports

Here's my problem in a nutshell: 1) My ISP blocks FTP ports on their side (not on the router, so I can't control that) 2) My Buffalo NAS won't let me change the default FTP ports 3) My ISP's ...
0
votes
1answer
808 views

Forced per-user ssh port

I want to allow access to each user on a server through a different port. For example; user1 can only be accessed by ssh through port 2201, user 2 can only be accessed through port 2202. I have ...