I'm pretty new to Ubuntu. I just want to open the most common ports namely   FTP (port 20 TCP/UDP) HTTP (port 80 TCP/UDP) SMTP (port 25 TCP) ETC   I've tried all the ways in iptables, ufw, and gufw.  In the end, it still remains unchanged with the same error:  Connection refused.  I can't even access the home page on HTTP port: 80 from the other device.
123565
My SoulSeek client Nicotine+ checks my open ports during initial configuration and promts that the one port number it needs is closed, cutting me off frmo about 50% of the users. Is there anyway I can open that particular port for the application to use?  RUnning ubuntu desktop 13.04. I have not manually installed any firewalls, but not sure if its included in the default installation.
119994
Every night I get hundreds, sometimes thousands, of failed ssh logins on my RedHat 4 server. For firewall reasons from remote sites, I need to run on the standard port. Is there anything I should be doing to block this. I notice that many come from the same IP address. Shouldn't it be stopping those after a while?
36375
There is a system B with the following open servers: I have a web server listening on port 80 and a ssh server listening on 22. However, only port 22 is publicly available. Now, I would like to create some kind of tunnel, so that I can access B:80 from A. However, my client computer A that would like to connect to the system B is not publicly open, either.  So, all I have is a client computer A from where I would like to access the server B and, there, an open port 22. On A, no port is open or can be opened.  What (I think) I would need is to open locally (on A) some port that connects in some way through port 22 of B to port 80 on B.  Is this possibly without using any man-in-the-middle open servers with multiple ports?
25367
I changed my SSH port in the /etc/ssh/sshd_config file and then restarted the ssh service. I implemented fail2ban and updated the port to my SSH under that config. I also then implemented the UFW firewall and allowed incoming connections to my new SSH port.  However, when I try and login with my SSH key using ssh -i /Users/myuser/.ssh/vpsssh user@555.555.555.555 it's trying to connect to port 22 instead of the defined port I have.
75880
HTTP servers usually operate at port 80. Yet NAT routers as most are these days assign port to outgoing requests so they would know when request is returned that which computer connected to it, it's suppose to be. They do it cause they can only use one public IP even though all computers behind router are given public IP address they are local IP address. Meaning they only work for everyone behind that router.   So how does server handles this. It only works at port 80, and router sends at whatever ports it wishes to do based on what is available and how it is programmed.   My understanding:   Computer A to router. 22.22.22.22.22:80 Router to World: 12.68.191.1.102:1 -ISP given IP address:Port to distinguish between computers connected to it.   Now what  Or maybe there is a difference between port and source port.
75342
I am setting up a ftp server on my Ubuntu 16.  After using the following command:  sudo ufw allow 21/tcp sudo ufw status verbose   I can see the output that says:     21/tcp    ALLOW    IN    Anywhere   But, if I type:  netstat -tnlp   It does not show the port 21 at all  Do I am doing something wrong?
63798
When I tried to connect my Ubuntu 13.10 to my VM Centos 6.5 using ssh appear the message "Connection refused" or "No route to host" even than I change the port, noting change.    I need to use SSH, VPN and Samba, but this IP in my VM Centos do not work.  How Can I resolve this problem?
91918
I have to use proxy servers to connect to the internet. I have set all proxies in my system proxy settings. Now I can connect to Internet using my browser and applications.  But I cannot connect to internet from my terminal.  I tried  export http_proxy="http://username:password@proxyserver:port/"    But still terminal applications cannot connect to the internet.
72372
I just installed Ubuntu. How do I set it up to allow me to ssh into it?  Right now I get "ssh: connect to host x.x.x.x port 22: Operation timed out".
100031
I have a little VPS I run apache and a Minecraft server on. I don't ever turn it off, but should I restart it for some reason, IPTables blocks most of my ports, including port 80. I've tried so many different suggestions on fixing this, but with no luck. Also, since the provider is OVH, the support is... lacking.  So, I've created a workaround, which I'm happy with. I created a simple shell script file to open certain ports I need opened on restart (80 and 25565 for now). The important ones such as 21 and 22 are not affected on restart.   The script looks like this:  iptables -I INPUT -p tcp --dport 80 -j ACCEPT iptables -I INPUT -p udp --dport 80 -j ACCEPT iptables -I INPUT -p tcp --dport 25565 -j ACCEPT iptables -I INPUT -p udp --dport 25565 -j ACCEPT /sbin/service iptables save   When I manually run it by typing /iptdef.sh, it runs fine, the ports become open and it's all good.  Of course, it's not practical having to remember to run it every time I restart the server, so I added a crontab. The problem is, it doesn't work/run. This is my crontab file:  */5 * * * * /backup2.sh */55 * * * * /backup3.sh @reboot /iptdef.sh * * * * *  /iptdef.sh   The first two lines work. They are just simple scripts that make a backup of a folder for me. The second two lines are what's not working.   Is there a chance that perhaps it's not possible to run iptables commands from a cron? It sounds silly, but I can't see any other reason for it not to work. The scripts have the correct permissions.
46460
I recently tried to delete unoDNS from my laptop. A member of their team gave me some commands to input in a terminal. It looked like it changed the nameserver address back to 8.8.8.8. But after I restarted my laptop I cant connect to internet at all. I am using ubuntu 14.04. Please help.
113909
i was wondering if nginx is able to handle http and https requests on the same port. [*]   This is what i'm trying to do. I'm running a web server (lighttpd) handling http requests, and a C program that serves a particular section of the document tree through https. These two processes run on the same server.   At the firewall level, i can have only one port forwarding traffic into this server. So what i'd like to do is to set up nginx on this server so that it listens for requests on a single port and then:  A) redirects all * requests so that they go to localhost:8080 (where lighttpd is listening)  B) if a user requests a URL starting with, for example, https:// myhost.com/app, it sends that request to localhost:8008 (C program). Note that in this case, traffic between the remote browser and nginx must be encrypted.  Do you think this could be possible? If it is, how can it be done?  I know how to do this using two different ports. The challenge that i face is doing this with just a single port (unfortunately, i don't have control over the firewall configuration on this particular environment, so that's a restriction that i cannot avoid). Using techniques like reverse port fowarding through ssh to bypass the firewall won't work either, because this should work for remote users having nothing more than a web browser and an internet link.  If this is beyond nginx capabilities, do you know of any other product that could meet this requirements? (so far i've been unsuccessful in setting this up with lighttpd and pound). I'd also prefer avoiding Apache (although i'm willing to use it if it's the only possible choice).  Thanks in advance, Alex  [*] Just to be clear, i'm talking about handling encrypted and unencrypted HTTP connections through the same port. It doesn't matter if the encryption is done through SSL or TLS.
77263
I am trying to access the server from the public ip. for that I have enabled port forwarding on the tp-link router for port 8069.  My pubic is is 123.201.xx.xx   When I try to access my public address with port number, it gives me no response.  I have checked  to resolve the issue. and get to know that my public ip and wan ip is different. i tried to access the server with the wan address and it allows me to access the server locally, not publicly.  my wan address is 100.66.xx.xxx.   what additional configuration i need to do to access server publicly? why my wan address and public ip is different?
15994
This is a  about DNS/Hostnames resolution to IPs/Ports   Example 1  I'm running a web server on port 80 and another on port 87. I would like to use DNS so that www.example.com goes to port 87. How can I accomplish this using DNS only?  Example 2  I'm running a service on my server on a non-standard port. How can I get clients to connect to this non-standard port automatically? Can I use DNS? Is there some application specific support where DNS could indicate the IP and Port?   Example 3  Do some application protocols specifically support hostname awareness, and allow special actions to be taken based on this information? Are there other questions on Server Fault that cover some of these?  Commandeering: This question was originally asking about running IIS and Apache on the same server, but the same concepts can be applied to any server software receiving connections from clients. The Answers below describe the technical problems and solutions of using DNS and application protocol support to assign a port number for a client to connect.
34104
I made a server and used my IPv4 address for the IP. I decided to scratch that server and make a Bukkit server so I can use plugins. I tried to use my IPv4 address which I used for my other server but I keep getting the message [17:31:15 WARN]: ****FAILED TO BIND TO PORT!  Is there any thing I can do to get a new address to use or is there a way to delete the old server? Do I need to use a different computer? Please help! I've don't know how to fix this problem. If you have any suggestions please tell me and I'll give it a try.
36120
My ISP has started blocking port 25 so I can not send email through my dedicated server any more.   I have several options:   Send email through the SMTP server provided by my ISP. Any problems with this? Setup mu server so that it receives email on another port instead of port 25     No one else sends email through my server so it should be OK. How do I do this on a Linux server? Buy a static client IP - these are not being blocked so far.   Which one is preferable?
59766
I'm trying to verify that a couple of our servers can communicate via certain ports before migrating some of our services to them, and that they're not blocked by our organizations firewall ACLs.  Makes Sense  [mrduki@mybox1~]$ nc -ul 40000 --- [mrduki@mybox2~]$ nc -zvuw2 mybox1.com 40000 Connection to mybox1.com 40000 port [udp/*] succeeded!   Doesn't Make Sense  [mrduki@mybox1~]$ nc -ul 40000 [mrduki@mybox1~]$ ^C --- [mrduki@mybox2~]$ nc -zvuw2 mybox1.com 40000 Connection to mybox1.com 40000 port [udp/*] succeeded!   In fact, if I do a port scan from 40000-40100, every single port succeeds.   If I do the same tests without -u (so that it tests TCP instead of UDP), I get 40000 (tcp) timed out: Operation now in progress errors, as I would expect (since I have no such TCP service listening on 40000).  Doing a sudo netstat -alnp | grep LISTEN on mybox1 though shows no such services listening on these ports. So what am I missing?