Fedora Servers :: F11 - Cannot Open Ports 53 And 25
Mar 28, 2010
I've been struggling for days trying to open port 53 and 25 but can't get it to work. My iptables at /etc/sysconfig contains the following:
# Firewall configuration written by system-config-firewall
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0] .....
On the server machine when I do port scan with nmap I see the following result:
Starting Nmap 4.76 [URL] at 2010-03-28 01:03 CET
Warning: Hostname localhost resolves to 2 IPs. Using 127.0.0.1.
Interesting ports on localhost (127.0.0.1):
Not shown: 986 closed ports .....
But when I try to do telnet from an external machine, e.g:
telnet <IP of host> 53
I get:
Connection refused
telnet: Unable to connect to remote host
I also did a port scan with a tool on an external machine but port 53 and 25 weren't listed as opened ports. Also CheckDNS.net on the server returns "Connection reset. Probably DNS server is offline". I am 100% sure that named and sendmail are running. When I do a ps -aux I see:
named 9261 0.0 0.3 85528 14784 ? Ssl 00:46 0:00 /usr/sbin/named -u named
root 2550 0.0 0.0 9536 1960 ? Ss Mar23 0:02 sendmail: accepting connections
"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?
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'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.
I have a JavaCL program trying to open a port on 41xxx and it is getting permission denied unless I run it as root. I would like to grant a single user this permission for opening this port. This program runs fine on a vanilla ubuntu install but not on server. Where does Ubuntu handle user permissions for opening ports?I understand this is typically a no-no on a server but this is an unusual circumstance.
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 am trying to setup a VPN on my FC 12 box. Looks like getting openvpn to work behind NAT is as easy as just forwarding the ports. Do I need to forward any specific protocols (GRE, etc)? Also, can I do this with one Ethernet port (IE: RJ-45 jack), or do you recommend a second ethernet port? I could add in another PCI ethernet card if it makes it easier. Anyone know if a single ethernet jack will work or do I need two?
Looking for a test tool where I can fire up any number of ports (TCP and / or UDP) to listen on.
I am currently getting my using nc but its only 1 port at a time (i know I can open up multiple sessions but thats cumbersome), it can't do UDP, and it closes at the end of the session.
A friend has suggested socat but it looks pretty much the same except it can do UDP, but also cumbersome, I have to manually output to a different file per port, etc.
Basically its so I can quickly test firewall and NAT rules.
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 am running apache2 and tornado web servers on the same server with one ip address.
The apache2 listens on port 80. Tornado listens on port 8888. I want to redirect requests from a specific ip port 80 to port 8888. I don't have the ability to change the port request on the device. It wants is looking for a web server on port 80.
Any other web server request should go to the apache.
I tried adding the following to /etc/ufw/before.rules
When I run iptables -L it doesn't appear. I have disabled and enabled ufw with no help.
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?
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 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 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'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 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 have installed Debian Jessie (<-- brilliant OS ) on my uncles Laptop (it is a Thinkpad E540) with Cinnamon as desktop environment. The installation was no problem. Everything apart from one minor thing works nicely. The minor thing however is the following:
I don't know what it is, but when I don't use a particular usb port for a while and then try to plug in a usb stick or a wacom tablet, it doesn't get recognized, it doesn't show up when I use f.e. Code: Select alllsusb. When I close the lid of the laptop and open it again, then the particular usb device gets recognized and cinnamon asks me what to do, f.e. open a folder and show the content of the usb stick I have plugged in. Because of the success on two other laptops I use the following
to save power on the Thinkpad (this is in no way my service script, I tuned everything using powertop in the terminal after having had logged in, the script above stems from a brilliant user here on the forum). Could it therefore be autosuspend that is not working properly here?
I have just switched over from firestart to gufw.I have set all incoming traffic to deny and all outgoing traffic to allow.I have rules set for incoming traffic, and have only opened 1 port on my system for torrents. My router also only has the same port opened which again is for torrents.I use "Network Tools" which is included on squeeze and do a portscan of 192.168.1.100 and 127.0.0.1 I get all kinds of crazy ports coming back as opened. What is even stranger is if I do a few scans, these ports change, so one port on one scan may come up as open, then it will disappear and a different port may show as open.
Mind you none but the torrent port is forwarded in my router, I have no idea what any of these other ports are, or why they are even showing up.What the heck is going on? I dont think this is normal? Am I at any higher risk for attack?
how to open firewall ports without using yast. The reason I'm asking is because I'm working on a .sh script for the installation of a couple of programs. Some ports need to be open for the programs to work, I find it really annoying to go to yast and type the ports manually every time. I've looked at /etc/sysconfig/SuSEfirewall2 but can't seem to find anything, I also know that after the changes I will have to stop start the firewall by running:
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:
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.
