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 :
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We are trying to create a message forwarder program that receive a message on Port A and pass it on t Port B. Also receive a message from Port C and Pass it on to Port D as follows.
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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
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my ISP block port 25. So i enable the port 587 in my postfix but every time of external ISP try send email to me, it try send on port 25. How can i "tell" to every external postfix to send me on port 587 ? Exist some configuration on DNS to this ?
View 1 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.
If I forward port 80 to port 3128 for squid with an iptable rule, does port 3128 have to be open on the firewall or is this all routed behind the firewall?
View 4 Replies View Relatedserver: LAMP - debian, apache2, mysql, php5. a bit info on my network: There is a another service here that already uses port 443 already. It made my website time out, hence the move to another port. PLus, i dont want the 2 services sharing the port. What I am trying to do is forward 443 requests to another port where the SSL service is running so I can hide my port number in the URL.
Here is my sites available conf file:
Code:
NameVirtualHost *:80
NameVirtualHost *:443
NameVirtualHost *:####
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so i set out to change the default smtp port the server uses because my ISP blocks port 25 and i need the email to work in outlook. this morning i could receive email, but not send it. so i did some research and thought that i needed to edit the master.cf file in /etc/postfix/ by commenting out this line: smtp inet n - n - - smtpd -oand replace it with587 inet n - n - - smtpd (587 being the port i want to use)somewhere along the lines postfix server stopped running and now i cannot get it to start.if i try using SSH it crashes immediately and if i restart it in simple control panel nothing happens
View 7 Replies View RelatedI edited "sshd_config" file and changed port 22 to a new port. After I restart ssh, it listens on port 22 and the new port. How can I disable SSH to listen on port 22? I'm using Debian.
View 6 Replies View RelatedI have just built a new postifx open relay server to allow my ISP clients to send emails. During testing of the SMPT protocol, I can managed to send emails to my localhost however, I can't send emails to other external mail server. Below is a test to a yahoo account. Aug 7 15:03:55 mx2 postfix/smtp[4050]: connect to g.mx.mail.yahoo.com[98.137.54.238]: Connection refused (port 25) Aug 7 15:03:55 mx2 postfix/smtp[4050]: F084EC8D76: to=<ellyu4@yahoo.com>, relay=none, delay=8.5, delays=1.2/0.05/7.3/0, dsn=4.4.1, status=deferred (connect to g.mx.mail.yahoo.com[98.137.54.238]: Connection refused)
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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 RelatedI 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"
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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
I've ben punding myhead on this issue. I've setup a new postifx server on rhel5. After editing the needed entries, i can't seem to send any outbound mails to yahoo or any other domains.My postconf -n is as follows:
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
command_directory = /usr/sbin
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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?
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 trying to set rxtxSerial to work so a Java app has access to a serial port (via SiLabs CP210x driver, port /dev/ttyUSB0). When I use update-alternatives --config java, there are 3 alternatives which provide `java'. I have tried openJDK and Sun. Both fail but with completely different messages.
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In SuSE firewall0. I do have a openSuse 11.4 and multiple IP addresses on eth0 interface
I run (trying to/have to) multiple TOMCAT servers.
I am trying to have each tomcat instance listen to on separate IP address for example:
What i am trying to do is to redirect
a) tomcat 1 -
a) tomcat 2 -
And so on.
I know that it has to be possible.
I do have just eth0/
Is is it possible. Do I have to create "vittual interfaces"? eth0:1, .......... and do redirection ?
"Server" has got just single interface - just 1 ethernet calbe goes to that server. I am planning to have 10-15 tomcat's on that server (I have to unfortunatley) and each has to run on port 80
Is it possible to "grant" permissions to normal users to run app on port 80 - that would solve me lots of problems if impossible to redirect.
I tried to setcap 'cap_net_bind_service=+ep' /path/to/tomcat ...... but no luck
i am running ncat (netcat's new version from nmap) on centos . I am listening on different ports. My question is , is it possible that when a connection is received on a port say 123, i redirect this connection to a different port and use the 123 port again for listening connections. ncat has an option -k which u can add with -l , it will force fully listen on the port. It can accept multiple connections on a single port but i want that once a client connects on to 123 port, he is forwarded to some other port and no longer on 123.
View 4 Replies View RelatedI'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'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 Replies View RelatedI 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 RelatedHow can i redirect data received on a port to another port located in a different machine? Can i do this using IPTABLES ?
View 4 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 got a request today from someone on the software development team that reads as follows: Quote: According to RFC 4409 client mail submission to an email server is supposed to use port 587. Server to server SMTP relays are to use port 25. When I am not on site, I can't email via my work account via my iPhone or my residential internet because my ISP(s) filter port 25 to only allow traffic to and from their mail servers. They do however allow 587 anywhere per RFC 4409. Just to send this email I am having to relay off my own server in California. get the proper ports opened on the mail server? [URL] So my question now is I'm wondering if my Postfix server isn't properly configured? Right now it's listening on the following ports:
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i 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.
