I'll explain this in one sentence: Is it possible to program a port-binding shellcode in which people across the Internet can connect to, without being thwarted by the router blocking their data because the port its bound to doesn't allow port-forwarding
View 2 Repliessudo ssh -L 750:192.168.123.103:873 username@192.168.123.103It does exactly what it's supposed to do, but how do i edit / remove this rule?Is there some config file where i can alter the forwarding? How does it get stored?Im using Ubuntu 10.10Server Edition (allthough i recon it would be pretty much the same across all versions
View 5 Replies View Related- I setup port forwarding of openssh :
connect 1: ssh -g -f -p 11111 -i /<path-to-private-key> user1@ip-server1 -L 22222:ip-server1:161
- Then I setup second connection
connect 2: ssh -g -f -p 11111 -i /<path-to-private-key> user1@ip-server1 -L 22223:ip-server1:3306
- Openssh waring to me "bind: address already in use"
- So I think port 22223 have had another program use,I use command:
ps aux | grep ssh /* find process id of second connection */
kill -9 <process-id-second-connection>
netstat -an | grep 22223 /*find which program use port 22223> */
- but I can't find anywhat
- Then I run again command :
connect 2: ssh -g -f -p 11111 -i /<path-to-private-key> user1@ip-server1 -L 22223:ip-server1:3306
- And I receive a error from OpenSSH :" bind: address already in use"
I have just set up shorewall on my router running Arch Linux. The external network is on eth0 and the internal network on eth1.I have set it up for masquerading and that works fine and I can open ports to the firewall. But I'm having trouble with port forwarding to my internal machines.The problem I have is that when port 22350 is forwarded to 192.168.1.3 on my local network, checking the port with nmap from a remote computer gives me:
Code:
PORT STATE SERVICE
22350/tcp closed unknown
[code]....
I tried to make "ssh tunneling", but failed and got this message.
Quote:
Administrator@windstory-PC /
$ ssh -R 7869:localhost:7869 windowsstudy@192.168.0.4
windowsstudy@192.168.0.4's password:
Warning: remote port forwarding failed for listen port 7869 Last login: Wed Jul 21 01:56:04 2010 from 192.168.0.2 -bash-3.2$
1. system environment
192.168.0.2 - windows 7 + copssh
192.168.0.4 - centos 5.4 x86 + openssh
2. Guide for setting "ssh tunneling"
[URL]
3. Added this to sshd.conf
Quote:
AllowTcpForwarding yes
4. "netstat -na|grep 7869" at 192.168.0.4
Quote:
[root:maestro:~]# netstat -na|grep 7869
tcp 0 0 0.0.0.0:7869 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:7869 127.0.0.1:53539 ESTABLISHED
[code]....
5. result of "ssh -vvv -R 7869:localhost:7869 windowsstudy@192.168.0.4"
Quote:
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
[code]....
6. I added 7869 for telnet service as follow;
Quote:
mytelnet 7869/tcp # My Telnet server
I'm not that great with mailservers, and just been thrown a curveball with a MS Exchange environment for which there is apparently no solution... yeah, right. But is there a workaround?
The problem is that the site mail (SMTP) needs to be sent via port 26 instead of the commonly used 25. Port 25 is mapped to a mailfilter, which apparently causes havoc with some of the mail, and the techs that have been on site trying to coax the Exchange server to co-operate have said that the only way would be to get rid of the filter.
The problem is that there are number of apps that are unable to have the outgoing port changed and so keep sending mail out on port 25.
I look after the Unix/Linux side of things at work, and I was wondering if there was an easy way to set up a Ubuntu box to receive mail on port 25 and just forward it to the MS box on port 26? So, in other words (and I hope this makes sense): monitor port 25, and forward whatever comes in on port 25 to the server on port 26. Simple portforwarding, or is it? What steps do I need to take?
When I use the following command:
ssh user@ssh_server -L 5500:localhost:5500 -p 22
everything works fine. I can log in, and local port forwarding is done. Otherwise when I use the command:
ssh user@ssh_server -R 5500:localhost:5500 -p 22
I get an error "remote port forwarding failed for listen port 5500". However when I try remote port forwarding in WinXP by use of putty there is no problem...
As it stands I have a small home network operating behind my modem/router. Some of the ports on this are forwarded to my PS3 for gaming but I was looking at forward some for my file server.
At the moment I've forwarded port xxx22 to port 22 on my server for SSH for instance. ANd similarly 21 for FTP (although it doesnt seem to want to connect for any more than a few seconds using that). What I was thinking of doing was placing a small website for a handful of ppl to use on the server too and port forward again - xxx80 to 80. It works just fine but I'm a little concerned on the security front.
As I've moved the port to something different from the outside world I'm presuming I will have already cut the potential for malicious folks to wander in but is there anything else I should be doing? At the moment there's no firewall operating on the server, usually as its hidden behind the modem/router. But if I open this thign up more permanently what should I be doing? I've read a few articles on it but I'm always left with the overwhelming thought of "Thats if theres no firewall in my router" as they just seem to do the same.
I want to set my ip as static and port forward it through a specific port can anyone help me with this im using ubuntu 10 with 64 bit OS
View 1 Replies View RelatedI have a mail server on which I would like to block port 25 on my eth0 for everyone except our external spam filter. the problem is that I want our users to be able to connect via port 10025 which is forwarded to port 25, which then is blocked...
View 2 Replies View RelatedI had to add them to my firewall script when I installed openvpn on my dd-wrt router:
iptables -I FORWARD -i br0 -o tun0 -j ACCEPT
iptables -I FORWARD -i tun0 -o br0 -j ACCEPT
iptables -I INPUT -i tun0 -j REJECT
iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE
what should I add/change to set up port forwarding of port 1000 to ip 192.168.1.200. also how to get the answer sent by 192.168.1.200 follow the same route used by the data received through port forwarding.
Up to now I've been playing with Ubuntu whilst storing important data elsewhere for about 2 years. Now I'm ready to move to Ubuntu completely but want to address my security.I'm currently using a desktop and server behind a hardware firewall / Internet router. The router has DynDNS and forwards port 80 to the webserver and a port I picked at random to the desktop 22 for SSH with private keys. SSH passwords are disabled.
The first question is, is there a danger of running different security levels on the two machines? I don't care about the server, there is no data on it so I currently forward port 80 and am considering forwarding ports 631 (CUPS) and a port for LDAP. Will this effect my desktop (which has info I don't want to loose).The next question is whether port forwarding / hardware firewall is actually a safeguard against attack.
I'm trying to SSH into my home computer from a remote location outside of my house's LAN and can't figure out remote port fowarding.
The guide here says to use the following:
Code:
I've tried connecting to my home computer through many combinations of the syntax listed above, read the man file, and looked online for help. But can't find out the proper syntax or a good guide that isn't written for Windows users using Putty.
Let's assume for the sake of simplicity that the public IP address of my home SSH server is 123.123.123.123, the private IP address of my home SSH server is 192.168.1.100, my home SSH port is 2222, and the SSH port at my current location is is 22. How would I write out the command?
Every time I try to connect I get a "connection times out" error.
I've got two virtual machines running, the first VM (VM1) has two network interfaces, one bridged with my real lan, one a private subnet. The second VM (VM2) has one nic, only on the private subnet.
I have VM1 acting as a router for VM2, giving access to my real lan for internet access. The problem I'm having is I cannot get VM1 to forward ports 80 (http) or 222 (ssh) to VM2 from my real lan.
Here is the script I've cobbled together from various (foreshadowing!) locations:
Code:
I have a question regarding port forwarding. I have a fedora server, with two eth cards: eth0 ---> external IP, eth1 ----> LAN IP I use SNAT for connection sharing. I also have an internet domain hosted on this server... let's call it [URL] Anyway, one of our computers in the LAN has some kind of web server on it, which must be accessed from the internet on the port 23700.
So, using iptables -t nat -A PREROUTING -i eth0 -p tcp -m tcp --dport 23700 -j DNAT --to 192.168.1.25 (the IP of the network computer) Everything works perfectly fine from outside the lan. When I type [URL], I connect to that computer. My problem is that inside the lan, typing [URL] does not work! It only works if I enter it by IP 192.168.1.25:23700 Is there any way to make the server forward my request to that specific computer even if I'm inside the LAN?
I'm trying to understand and set up port forwarding with iptables. So far I've read a lengthy tutorial on iptables, and I've Googled for hours, searched this forum, but I've been unable to come up with a solution that works for me.The situation I would like to achieve is the following: on one machine, there is a TCP server running bound to its external IP, port 9999. I would like to let another machine connect to this TCP server on port 9000 by forwarding port 9000 to 9999.All the policies of the iptables chains are set to ACCEPT; and I have set net.ipv4.ip_forward = 1. I have no problems using SNAT/MASQUERADE on the same server machine.I have tried the following:
Code:
iptables -F
iptables -t nat -F
iptables -t nat -A PREROUTING -p tcp -i eth0 -d ${SERVER_IP} --dport 9000 --sport 1024:65535 -j DNAT --to ${SERVER_IP}:9999
In order to test this rule, I started a TCP echo server on port 9999. I can connect to it on port 9999, but not on port 9000- this gives me 'connection timed out'. When I do 'iptables -t nat -L -v', I can see that the rule does get matched once per connection attempt.
If I forward port 5764 to port 80 to my VOIP device, I can nmap and get a proper connection. If I forward port 5764 to port 22 to my server, it comes up filtered. It even happens if I try forwarding port 80 to my server. So I'm sure it has something to do with my server, but I'm not sure.Here's my Linksys iptables:
Code:
:wanin - [0:0]
-A FORWARD -i vlan1 -j wanin
[code]....
I have a machine with Ubuntu Server and VMware Workstation 7 installed. I have tried NAT port forwarding to gain Remote Desktop access to a Windows virtual machine, but it did not work for whatever reason. I've done this by editing the nat.conf file in the /etc/vmware/vmnet8/nat directory. Unfortunately it still does not work. Also, I would like to ask if it is possible to port forward using the virtual machine itself and not the host.
View 1 Replies View RelatedI've been beating myself over the head with iptables and CANNOT get port forwarding to work. Here's my situation: Static LAN IP on eth0 Static internet IP on eth1 ip_forward is turned on by uncommenting in sysctl.conf Here's the output of iptables-save:
Code:
# Generated by iptables-save v1.4.4 on Tue Mar 8 10:34:12 2011
*nat
:PREROUTING ACCEPT [2443:347058]
[Code]...
Edit: by the way, the intended purpose of this machine is to server as a gateway and firewall. MASQUERADE is working, for whatever that is worth. And the host behind the firewall that is serving up http is definitely working too. All that is not working is getting hosts on the internet talking to hosts behind the firewall.
My understanding is SELinux adds type enforcement to standard Linux. This means that both the standard Linux and enhanced SELinux access controls must be satisfied to access an object. Which means that thing that is prevented to do in the normal standard Linux will be also prevented in the SELinux System? Does SELinux make it possible to run a non-root software to bind to a port < 1024? something that standard Linux won't allow? If not, what other suggestions do you have for allowing a program to run as non-root but able to bind to privileged ports? I know all about using the port re-direction such as ipchains, iptables.
View 4 Replies View RelatedI'm having a mare with SSL with Apache. I have set it up and if I go to the follwoing address http://192.168.1.2 it seems to work and the pages are delivered to my browser. However if I try to access it from an exernal PC it will not work.
I can get to the non-ssl part of the site so the static ip is resolved and the port forwarding all works.
Does any one have any ideas (and in fact i think I may have just solved it - Ports - 80 mis open but I haven't done anything with 443. Will check it out and post back.
Is there any way to verify if packets being trafficked over a certain port are valid for the service you want to use this port for?
One obvious example that probably clarifies my question:
When I open port 443 (outgoing or incoming) for https/ssl traffic, I don't want this port to be used for say openvpn traffic.
Thus: when someone wants to surf to a website with https, it should be ok but if someone wants to connect to his home openvpn server over that same port, it should be blocked.
I want to do a simple port redirect, i.e. whatever comes trough whatever interface on port AAAA will get redirected to port BBBBI thought that iptables -t nat -I PREROUTING --source 0/0 --destination 0/0 -p tcp --dport AAAA -j REDIRECT --to-ports BBBBhowever it doesn't work, e.g. nc -v -w2 -z localhost AAAA gives:
nc: connect to localhost port AAAA (tcp) failed: Connection refused
while
nc -v -w2 -z localhost BBBB
[code]....
I have a mail server i need it to send message via port 587 not port 25, i make some changes to my postfix server which i use and it is already successed making a telnet to 587 port like it :
[Code]....
my ftp (with SSL) server is behind firewall.
Code:81.81.81.81 FIREWALL (my external address) 192.168.1.5 - FTP server How to create portforwarding for such a configuration. I`m not interesting about iptables rules. I would like to know which port should I redirect and how ? FTP server usualy using 20 and 21. What about VSFTPD with SSL ? Also 20 and 21 ?
I did local apache server at internal ip 192.168.1.2 and i wanna to do port forwarding to enter to it by my external ip address ?
View 4 Replies View RelatedI am having issues with the DREADED port forwarding. *why* is this important? *why* does it become such a chore to change? trying to run xlink kai on karmic. i have access to the routers in the house. the primary (#1) router is a standard issue Linksys, the other router is my DDWRT router which connects wirelessly to #1.
View 3 Replies View Relatedi have already changed the sshd_config file but anyone who logs in can access to the internet what should i do?
View 5 Replies View RelatedI have a ubuntu 9.10 on my desktop in my office and I have another ubuntu on my home desktop. Both machines are behind a router. I guess many people have already asked the same question: how to remote control the office desktop from my home desktop?Many posts discussed about solving this by setting up ssh and port forwarding. But my situation is that I cannot control the router in my office so I cannot set up any port forwarding for my office desktop. So I guess my question becomes how to remote control my office desktop without setting up any port forwarding on the office router.
View 3 Replies View RelatedI currently use a commercial VPN when working overseas for secure internet access.
I now also need to VNC to a home ubuntu desktop (which runs software 24/7 that I need to periodically check).
When overseas, I use a Ubuntu laptop and an Android tablet.
For the VNC I intend to use an SSH tunnel. So my question is: should I ALSO set up openVPN on the home computer (so I can stop paying for a commercial provider which routes all my traffic twice across the Atlantic...) or is it easier/better to use the SSH tunnel for the secure webbrowsing too? Something like a SOCKS proxy?