Ubuntu Networking :: Checking For Open Ports Remotely
Aug 19, 2010
I'm trying to set up an SSH connection from my school to my home, but not on port 22. I originally tried port 2222, but it didn't work. I called my school IT people and they said they block that port. I asked if they care if I set up an SSH and they said no, but that they wouldn't tell me which ports are blocked and which are open for "security" reasons (which I guess I can actually understand). They suggested just using port 22 or 222, but said if a ports open I can use it.
My question is, can I check ports without setting up SSH? It seems like a hassle to try a different port every day on my home SSHD file, come to school, see if it works and repeat. Is there a way I can check my computer home for connections that could connect, even if there isn't a service listening? I don't know how to do that, or even if its possible. If not, I suspect I'll just try a few until I find something that works, or just go ahead and use 22.
I'm working on my first bash script. My script will do several things but right now I'm just trying to get the basic part of it down and working.I have a section that looks like this
The problem is that if you take that right now and run it, it will return back good in that it does exist. What I need it to do is pass back that it's bad because it doesn't exist (that is unless you actually do have that directory in your root).
A few months ago I installed Ubuntu 9.10 on my girlfriends laptop, on her request, as she didn't like Windows any more. Since then the internet connection periodically slows down due to too many open ports/connections. Always when this happens I call our ISP and usually there are around 80-200(!) active connections to various IP's.
She is not downloading torrents or anything. She only uses Firefox and a few open tabs as people do. Skype is open. Wireless internet connection.
I am thinking either Ubuntu is updating more or less constantly or the ports/connections aren't closed "after use".
I'm trying to open my ports all the way, but for some reason, I am unable to do so. I've forwarded the ports I want open in my router (I switched between two routers to make sure), I made exceptions in Firestarter, and I even added UFW rules, but when I use pretty much any and every port checking tool out there, the ports eithere back stealthed or closed.I'm not a complete noob, and I'm not an expert, but I'm p sure I'm doing everything right, seeing as there isn't much to screw up.The reason I'm trying to fully open these ports is because I'm getting this dumb 'No Incoming Connections
I have been running Ubuntu 10.10 and have found that at any time I am connected to the Internet that I will randomly see high port numbers open when doing a port scan on my computer all are in the unknown listings with five digit numbers so I don't know what is going on or who is using them. Please check your system to see if you are having the same thing happen by using network tools and filling in your local ip address in the port scan tab. If you shut down your Ethernet interface and run port scans the high ports are no longer open. this will at least keep whoever is using your ports at bay when you are not using the net.
I would like to open some port from IN to OUT pop3,smtp.whenever i tried to add some rules to existing iptables it gives me an error.Applying iptables firewall rules: iptables-restore: line 21 failed
I forwarded ports 28900(TCP/UDP) and 5029(UDP) to my linux box for a game. Testing my ports with a website now shows these ports as "connection refused" rather than "timeout" which means the connections are getting to my system but the iptables are blocking them. But I added 28900 as a test and it still won't accept anything on this port. This is my output of iptables -L
I need to ensure ports 6112 through 6119 are open. I tried using Firestarter to do this, but when I search for what ports are open, it says none of them are. I use Ubuntu 9.04.
Yesterday I switched from CentOS to Ubuntu, and wanted to install TeamSpeak3 which runs on ports 9987 UDP and 10011 TCP. The TeamSpeak3 worked fine on CentOS before this.
I believe the only firewall for Ubuntu is "UFW", am I correct? If so, "ufw status" reports:
Code: Status: inactive
I do have other things running on UDP (Counter Strike Source servers) and people can connect just fine.
When I telnet localhost 10011 I get a response from the TeamSpeak3 server:
Code: Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. TS3
Welcome to the TeamSpeak 3 ServerQuery interface, type "help" for a list of commands and "help <command>" for information on a specific command. However, telnetting from outside just gets no answer, this is what leads me to believe it is a firewall in the way.
Normally I use 'netstat -an' to determine if a daemon is listening on a specific port. The excerpt of this command below doesn't list things like vnc (5900) on ipv4. It does however show it on ipv6. My issue is I want to know how to determine if it is indeed listening on ipv4 as would normally be seen with 0.0.0.0:5900. It would appear that all ipv4 ports are internally being redirected to ipv6. Of course this does simplify things, but it also leaves me unable to reliably determine the ipv4 listening status. How I can tell at a glance if a specific ipv4 port is being listened on? Is there a way to force netstat to list the ipv4 listens specifically? Code: art@eee1:/proc/sys/net/ipv6$ netstat -an Active Internet connections (servers and established) .....
I've installed a fresh copy of the latest 10.04 distro, lucid lynx and have problems connecting to the machine via ssh because the ports are all blocked (using nmap to check). In past releases, changing the gdm.conf flag "TCPDISALLOW" from true to false would fix this. In the new /etc/gdm/gdm.schemas, I've tried making a similar change, but it's still not opening things up. I've downloaded gufw and have made sure the firewall is off. So, I'm not sure what to try next.
I'm not terribly new to Linux, but I am new to the forums, so hear me out! I am in the process of creating an electronic mapwall for our meteorology program, and have designed the computing system from scratch. I have two Linux Boxes, each with capabilities for 6 attached monitors...a total of 12 displays driven from two machines. My intention is to have one machine be the master...it has a touchpanel control. The inputs to the touchpanel will then trigger events for the both the master and the slave machine to display. Each of them has a specific IP address (DNS entry), and are not on a subnet.
Now...is there a way to remotely login to the slave machine and have it display on it's OWN monitors? The code is Java and which works on the master machine to animate directories of .gifs for each of the master's attached monitors. I will most likely have Java execute shell commands for the remote login (ssh), but I believe the answer lies somewhere in the X-configuration. Do I have the machines in an adverse configuration (creation of a subnet would be better)? Lots of questions...lots of desire...few answers!
I set up a vnc connection to my machine the other day and while doing that checked out any open ports.To my astonishment my ftp port is open, although I double checked the firewall and there's no check in the checkbox for the ftp port. I didn't add a "other ports" rule or anything as well.So, how would I be able to fix that?
I'm locking down my laptop. I know I can use a firewall to ensure nothing gets through that I didn't catch, and I certainly plan on using one, but in the meantime, I want to know what exactly is running on my system.
nmap localhost returns: Code: james@james-linux:~$ nmap localhost Starting Nmap 5.00 ( http://nmap.org ) at 2010-07-26 23:33 CDT Warning: Hostname localhost resolves to 2 IPs. Using 127.0.0.1. Interesting ports on localhost (127.0.0.1): Not shown: 994 closed ports PORT STATE SERVICE 25/tcp open smtp 111/tcp open rpcbind 139/tcp open netbios-ssn 445/tcp open microsoft-ds 631/tcp open ipp 2049/tcp open nfs Nmap done: 1 IP address (1 host up) scanned in 0.18 seconds
However, I know that localhost goes back to the loopback interface, 127.0.0.1. So, to see what was really open, I ran nmap 192.168.0.108, which is my laptop's IP at the moment.
Code: james@james-linux:~$ nmap 192.168.0.108 Starting Nmap 5.00 ( http://nmap.org ) at 2010-07-26 23:33 CDT Interesting ports on 192.168.0.108: Not shown: 996 closed ports PORT STATE SERVICE 111/tcp open rpcbind 139/tcp open netbios-ssn 445/tcp open microsoft-ds 2049/tcp open nfs Nmap done: 1 IP address (1 host up) scanned in 0.14 seconds
Now if I understand correctly, I can attribute 139 and 445 to my Samba share. That I'm okay with. What I don't know is 111 and 2049. Does anyone know what these ports are, what's running on them, and how I could turn them off, supposing that they are a security risk?
I'm getting heat from the head networking office that ports 21, 110, and 143 are open. I can telnet to those ports from a remote machine (not localhost) and get a prompt. There does not seem to be anything listening on those ports according to netstat. I've tried using iptables to discard all traffic to a from those ports but I can still telnet to them. This is a lucid desktop machine.
I'm using ubuntu-linux ( ubuntu 9.10)I use utility autoscan network to scan the systems available in local area network of my hostel.It shows my open TCP ports : like Ssh , Smtp , Http , NetBios-ssn , Microsoft-ds , ipp , Mysql , Postgres.Are all these services need to run all the time or I can manage the ports.Don't know much about it just want to know these ports are by default open or I can manage them.
I have a small question regarding remote access through SSH. Here is the thing: it's been a while now that I am using SSH to remotely login servers, and more recently my own machines to transfer information from my school's workstation to my Aspire One (I effectively work in the Aspire One through a 24 inch monitor).
Anyway I was wondering if it is possible to open programs like evince through SSH. I'll describe what I am doing: the Aspire One sits next to my workstation (so I am seeing it's screen as well) and in the workstation I work in LaTex documents actually residing in the Aspire One, so what I want to do from time to time is to open graphical apps in my Aspire One from my workstation through SSH (needless to say that I open the graphical session in the AO with the same user I do SSH, and the AO runs Fedora 12).
I installed Ubuntu 9.10 recently. I heard that there will be no open ports in the system unless I specifically open one. How do I scan to find a open port in my system.
when i enable my ufw it completely shuts me out and closed my internet connection. i installed firewall configuraiton interface and through it defined rules to accept incoming internet connections on port 80, i can see the rules are there but when i enable my firewall it just shuts me out completely again. when i do(with my firewall enabled):
Code: $ sudo ufw status it gives me: Quote: Status: active
[Code].....
I also messed around with fwbuilder and iptables but since then deleted fwbuilder(besides i just compiled firewall policy and never actually installed it because of errors while trying to install it. Iptables I cleared with:
"Ubuntu Server has no open ports by default" - [URL]. Does this mean right after a 10.04 Server Edition installation, if a user wants to start a web service e.g. a Java process to listen on say port 8080, he would have to configure the firewall first?
Just did a check on "shields up" and it says that ten of my ports are open. I get the same result with or without both shorewall and firestarter. I suspect it may have something to do with the mysql server packages added automatically during installation. Am I right. If so, what can be done about it? If not, has anyone any idea how to keep my ports closed?
I'm trying to setup oracle10g but, whenever I try to go to my database homepage http://127.0.0.1:8080/apex I get an "unable to connect to" error. Only reason I can think of as to why I can't connect to it is because my ports aren't open. I also recall SELinux complaining about something awhile ago, I can't seem to bring that up any more for some reason.
I have a problem with one of my new OpenSuse installation. I install ntop on this machine so the port 3000 become open, but when i want to use it on a other pc, it cannot see the open port. I really don't understand why i cannot access this port.
I disabled firewall to make sure everything pass.
Here my ntop on my localhost
Nmap done: 1 IP address (1 host up) scanned in 0.07 seconds
Here my ntop from another host
Nmap done: 1 IP address (1 host up) scanned in 0.07 seconds
Recently I've updated my small file server at home (Ubuntu 9.10) (Linux ubuntu 2.6.31-16-generic) and after I restarted my system No Ports where open anymore. I use ssh, vsftpd, apache2 and samba ... nothing start after reboot, I have to start it manually. I don't know what happened and if is it even direct result of some updates. I have another machine like that at work and there was no problems after resent updates.
I am having trouble getting ports to open, on the router that the server is connected to it is set to DMZ, so everything passing through the router should go to the server right? but when I use a port checker none of the ports that I need to be open are. so my question is does ubuntu have a built in firewall that no one told me about? or something that would block me from having the ports open?
I'm trying to open ports in Firehol for PS3 Media Server. So far I've tried all options from this Firehol "adding services" page and none of 'em is working for me. Here are the IPs:PC : 192.168.1.139PS3 : 192.168.1.138TV: 192.168.1.131PS3 Media Server Port: 35355If a port can be opened for specific IPs then I would like to open one for only 2 IPs.Firehol configuration:
version 5 # Accept all client traffic on any interface interface any internet
I've tried to set up a Hadoop cluster on a few freshly-installed 10.04 Server Edition machines and hit a problem. (I was able to set up the cluster using Desktop edition previously). The issue is that I can't connect to the service even though the Java process is running and listening on the port and there is no error in the logs. Anyway, I started to wonder if it was firewall issue so I googled it and found conflicting information.
1. "Ubuntu Server has no open ports by default" - [URL] 2. iptables shows different info. ufw is also disabled.
I even tried to enable ufw and did "sudo ufw default allow incoming" but still no help. The only package I manually selected during installation is OpenSSH server.
