I am trying to open VNC ports(5901,5902) on my RHLinux machine using iptables. I am able to do it from GUI system-config-security. Go to the Administration > Security Level and Firewall, then select "other ports" at the bottom and enter the portNum 5901 to open and select tcp, then click OK and OK again to save your settings. From my windows m/n iam able to open vncsession using vncviewer on 5901 port.But when I am trying to do it from command line:#iptables -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 5901 -j ACCEPTThis command added the entry in /etc/sysconfig/iptables and listed in iptables -L command.Then I saved and restarted the iptables.#service iptables save #service iptables restartWhen I am trying to open the VNC session from vncviewer, it is giving me error and session not opened.Is there some thing I missed here? where can I check the logs for this? I definetly need
I am running a server with ssh and a vpn server set up. It is behind a debian router with a firewall which uses iptables. i have it set up to forward ports 22 and 443 to ssh on a computer within the LAN(so when on a restricted network i can still ssh into my network) and forward anything to 1723(for my vpn) to that box also. However, the only port that gets successfully forwarded is port 22. The other two appear closed. here is what the script looks like:
I want to portforward client connections from an ubuntu lts server to another external server. btw i am a noob on iptables. i have tryed using the basic commands for iptables with no success. For example:iptables -A PREROUTING -t nat -i eth1 -p tcp --dport 7878 -j DNAT --to 91.23.45.67:7878iptables -A FORWARD -p tcp -i eth1 -o eth0 -d 91.23.45.67 --dport 7878 -j ACCEPTso basically i just want a rediraction for from one ip to another. Example: A client tries to connect to ip 123.45.67.89 on port 7878 and the server forwards him to ip xx.xx.xx.xx on port 7878, meaning that xx.xx.xx.xx is the actual server with services. Server with ip 123.45.67.89 is only forwarding the client to external ip... how can this be done in a simple command?
I like to set in iptables to allow access from one host to my server on any ports.Currently the iptables have been configured to deny all and to allow access only to those I've specified.
Because my ISP is blocking every IP port under 1000, I'd like my local nat'ed server to be able to translate incoming and outgoing traffic from some port above 1000 to the default server port locally.Example :
To connect to my IMAP server (default port : 143) from the outside,I'd connect to my public IP, port 1143 (opened and nat'ed to the right server on my router) and the server would translate this port to 143 on the same machine.I wish I could simply configure my router to do that but sadly Linksys doesn't permit such setting... I also could modify the listening port of my server but I prefear to keep the default port inside my network.I think that iptables is the right tool to do that and I never used it and I must say that this tool is not so easy to configure at first sigh
I'm having some issues settings up a transparent proxy server, which should allow only regular web browsing (port 80), any other port (including HTTPS (443)) has to be blocked, as well as any other port. Right now, I'm using Debian 6 and Squid3. The server only has one NIC. The topology is like this: Clients <-> Proxy Server + DHCP Server <-> Internet
With this setup, the network does have internet access and the websites I whitelisted are the only ones accesible via browser, however port block is not working, every port is open, hence why trying to access blacklisted websites through HTTPS is possible. Seems to me Squid3 is doing it's job fine, however IPTABLES for some reason seems to be redirecting all the trafic to port 3128 (Squid3 port). I could be wrong, but I've been unable to do anything related to ports with squid3 (either whitelisting or blacklisting).
For Iptables I used: Code: iptables -A PREROUTING -t nat -i eth0 -p tcp -j REDIRECT --dport 80 --to-port 3128 iptables -A INPUT -i eth0 -m tcp -p tcp --dport 80 -j ACCEPT iptables -A INPUT -i eth0 -m tcp -p tcp --dport 22 -j ACCEPT iptables -A INPUT -i eth0 -m tcp -p tcp --dport 3128 -j ACCEPT iptables -A INPUT -i eth0 -m tcp -p tcp --dport 443 -j DROP
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 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 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 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.
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.
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.
We do NOT support samba on our Unbuntu servers but still zillions of windows machines are constantly trying to connect on the SMB ports. I've added a rule that drops access to destination ports 137-138 and that seems to work. But it creates many many log entries documenting that the packet has been dropped. I've been researching and cannot come up with a way to suppress logging for these drops.
I have a Suse 10.3 router with 4 network cards. 1 is to connect to the big network and thereby also the internet, 2 are for 'client' subnets and I want to use the last one as a DMZ. In this DMZ will be a web server which has to be accessible from the other 2 subnets and from the big network. I could do it with a few simple clicks in Yast firewall, but I have some issues with this firewall and there for I want to use it as minimal as possible, using Iptables.
So now I'm struggling a bit with Iptables. Basicly what I'm looking for is how to block all ports but 80 in this last subnet with iptables.