Networking :: Directing Packet From One Port To Another Port Of Another Machine
Apr 25, 2009How can i redirect data received on a port to another port located in a different machine? Can i do this using IPTABLES ?
View 4 RepliesHow can i redirect data received on a port to another port located in a different machine? Can i do this using IPTABLES ?
View 4 RepliesI 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
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I am using squid proxy server in my Linux machine for caching. Now i want run my squid in transparent mode not set proxy settings in browsers.Like squid is running port 3128. If we redirect the port 80 packets to port 3128, looping is occurred.How to avoid looping?
View 5 Replies View RelatedI 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 :
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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...
I'm trying to use iptables in order to forward all the incoming packets for port 5555 to port 5556 on the same server (192.168.2.101).
I wrote the following commands:
iptables -A PREROUTING -t nat -i any -p tcp --dport 5555 -j DNAT --to 192.168.2.101:5556
iptables -A FORWARD -p tcp -m state --state NEW -d 192.168.2.101 --dport 5556 -j ACCEPT
I'm using a Debian servers, as router/firwall.. I've two ethernet interfaces into the server, one for wan and one for lan. The i use SNAT so my LAN clients can access the internet throgh the debian router. That is working... Now i want to be able to access servers on the LAN site from the WAN site, and i wanna use port address translation (PAT). I have a FTP server running on a lan server, so i'm trying to portward port 21.
iptables -t nat -A PREROUTING -p tcp -i eth1 -d (WANIP) --dport 21 -j DNAT --to 192.168.1.2:21
When people try to access my FTP from the WAN site, they are redirected to the local FTP server, and they are promted for crendentials, but when the credentials are typed, and the local ftp server should answer the wan request, the connections dies.
The wan clients are being promted for credentials, so they are redirected to the local lan server, but after that the connections dies, so i think there is some kind of nat problem, when the local lan server is trying to respond to the wan request..
Here i my iptables script:
#flush table
iptables -F
#input regler
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I make an application on GNU/Linux which listening on a MULTICAST stream, so I open my unconnected socket, bind it on a MULTICAST address and a port, join the multicast group with the "setsockopt (IP_ADD_MEMBERSHIP)", then I receive datagram on my socket.
Now I've two different instances of the same application that run with their own MULTICAST address and port. And what I found strange is that, after a misconfiguration, I switch the ports, for example:
Emitting on 225.0.0.1/23451 and 225.0.0.2/23452
Receiving on 225.0.0.1/23452 and 225.0.0.2/23451
And my receiving part doesn't care about the MULTICAST address, it looks like the socket is listening on the port number only! I mean that the receiver [225.0.0.1/23452] take its datagrams from emitter [225.0.0.2/23452] and vice-versa!
I have a reverse ssh connection established from a remote machine to my local machine - it is established with autossh from the remote machine - I know it is connecting because I can see the two ssh processes on the local machine - and, when I kill the two ssh processes, two new ssh processes are immediately established. But I cannot login to the port on the local machine. I have tried everything - it simply refuses to connect. This remote machine is miles away and not readily accessible.
Code:
ssh -p 7766 -vvv user[at_sign]192.168.1.108
OpenSSH_5.1p1 Debian-6ubuntu2, OpenSSL 0.9.8g 19 Oct 2007
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
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I'm wondering if there is some way I could utilize netcat or socat to "tap into" this connection from my local machine??? (My ultimate goal would be to get to a shell on the remote machine.)
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.
I have had a look at the the information on the ubuntu forum about this but am having trouble getting the server to do what i want it to do.
I have a VPS running ubuntu 9.10 and i am trying to set it up to redirect port 25 to a remote machine via a VPN connection (remote machine connected via VPN)
i have tried setting this up in the firewall using webmin but it is not working.
i have a problem........ How to redirect local http port to remote ip ddress(192.168.10.64) using iptables..my destro is Centos 5.3 my rule is this iptables -t nat -A PREROUTING -s 0/0 -d <my local ip> -p tcp --dport 80 -j DNAT --to-destination 192.168.10.64
View 1 Replies View RelatedI want to transfer the audio file on linux machine using Ethernet port, is it possible?
View 6 Replies View RelatedI am trying to generate a UDP syslog packet from my C application. But I am facing a problem with a Cisco Router ACE that does not like the Source Port being '0' and thus drops the packet.How can I specify the Source Port in the UDP header to '514' as stated in RFC3164 (Section 2: Transport Layer Protocol)? "It is RECOMMENDED that the source port also be 514 to indicate that the message is from the syslog process of the sender"
View 1 Replies View Relatedi have an embbeded hardware that uses bootp for booting from a Network Managemnt Host (NMH)on the same ethernet. The embedded hardware has both kind of ports i.e ethernet as well as E1/T1. I would like ask, what do i require to establish a communication-link between the embedded hardware and the NMH throuh E1/T1 ports of embedded hardware, so as to make it boot through from E1/T1. Further, NMH possesses only ethernet port. Just to refine my questions i'd like to know what additions do i need to do on my NMH , like may be i have to put an E1/T1 port or is it possible that the E1/T1 port can be directly connected to an ethernet port on the other host.
pardon me if i am not making absolute sense here as my knowledge is limited on Layer 1 and layer 2.
how to access networking port and run scripts on that port so as to gain access of remote machine.is that possible through command prompt or through software.
i kno ip address of my frnd who is chattin with me .okay.i want to run an application on his computer .i came to kno tht we can run script o through port
I am using VirtualBox as virtualization machine. My topology is:Quote:Internet=====(eth0)HostOS=SLackware(eth1,br0)=====(eth0)GuestOS=slackwareCondition each OS:
HostOS:
eth0 = 192.168.7.80/24
Gateway = 192.168.7.1
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I installed ZTE MF 626 modem in my F10 with kernel 2.6.27.12-170, i run usb_modeswitch and so far things happened normally. Watching through /var/log/messages it says that F10 detects two port device for this modem: ttyUSB1 and ttyUSB2, and in the sequence it disable port ttyUSB1 BUT Network Manager still set this port.I mean, when i connect via wvdial appointing to ttyUSB2 i get connection, but Network Manager fails to do it appointing to ttyUSB1. How to change device port in Network Manager?
View 1 Replies View RelatedI successfully installed the virtual box on my fedora 8 system, and also created a virtual machine with windows xp OS, it works nicely, I try to configure the serial port of my virtual machine and try to configure the path for the port "screen shot are attached" it gives me the error message also the "screen shot are attached" for your review.Is kind of mistake is going on during the path setting, and how to set the path for configuring the serial port of my virtual machine so that I can use the hyper terminal tool of windows.
View 4 Replies View RelatedI am running lmgrd on CentOS5, but it returns Failed to open the TCP port number in the license. The port is 27000, how can I open that port?
View 5 Replies View RelatedRight now I have a machine set up running Fedora. I have configured inittab to accept Console Logins, but I am having problems getting my netbook running PuTTY to connect. How would I go about finding the Host Name and Port to connect to?
View 6 Replies View RelatedI 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
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i want if a port (exp. 1001) have 20 connections that the next new connection forword to an other port (exp. 1002).
View 2 Replies View RelatedVERY new to linux, erm but I have an issue that needs solving!I recently moved to university, where their network blocks sftp port 22, this means that I cannot connect to my FTP server which is running a version of linux.Now I've got this ftp server connected to a seedbox and it was created using the following walk through..Code:I have written this guide for a friend, but I though it would be useful for others as well.
There are several guides floating around, but I found that most always cock up in some way. This one is tried and tested to work on Debian Etch (on an OVH rps, but should apply to most servers).If there is a new stable release of rtorrent/libtorrent then I will update this guide to show you how to update it (without reinstalling the whole server).
At the bottom there are also instructions to install ftp access & some network monitoring software.Basically, I would really like someone to be able to construct the commands on how to change the listen port for sftp connection on linux or add another port to the list that Linux would use so that I could put in through putty.
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
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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
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6. I added 7869 for telnet service as follow;
Quote:
mytelnet 7869/tcp # My Telnet server
sudo 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 RelatedIs 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'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?