I tried searching and tried different things and have failed miserably. What I am trying to accomplish is have postfix listen on port 587. I have read that I should do this using Linux Firewall rules as to not mess with postfix config. Here's what I have in my ip6tables.
Code:
iptables -t nat -A PREROUTING -p tcp --dport 587 -j REDIRECT --to-ports 25 However, when I restart ip6tables I get unknown arg --to-ports
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 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!
On Fedora 13 is there anywhere else on the system that I have to change to get Apache to Listen to an assigned port, something other than 80. Suppose for instance I wanted Apache to Listen on port 94. I told by the site that their router is forwarding apache to port 94. That doesn't mean I change the Listen in httpd.conf. correct. Apache is still expecting connection on port 80 but in this case 80 then gets forwarded in the router to 94. This is my understanding.
View 5 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"
[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 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]....
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 just installed KVM on a new system and just found out the hard way that virt-manager cannot be installed on the same machine because of a library conflict, so I will have to manage my VMs from another machine. I will use a SSH tunnel to forward the port, but I don't know what it is. Also, how do I start KVM?
View 4 Replies View RelatedI'm running Ubuntu 9.10, and am trying to get proftpd to listen on a port other than 22. I've modified the proftpd.conf file, as well as adding the desired port to my /etc/services file, yet if I try anything other than port 22, the connection is refused.
View 3 Replies View RelatedIt appears that X Windows under Ubuntu (or Gnome?) is started to listen to a Unix named socket, instead of a TCP port number, for client connections. That's what SSH is forwarding when it does X forwarding. I need to start X applications on a remote machine, and then close the SSH connection. So I need to make the connections directly. This is within a LAN on private IPs, so security is not an issue. I searched on help.ubuntu, but there appears to be no particular document that covers this. Anyone know where this is configured to enable it to listen on a TCP port like the usual 6000?
View 6 Replies View RelatedCan't seem to access my squid server on port 80. I have port 80 allowed in the conf for this IP. apache is listening to port 80 but only on the 2nd IP. iptables is allowing through port 80 incoming nmap shows no ports open on 80 though:
Code:
Starting Nmap 5.00 ( http://nmap.org ) at 2009-08-20 11:19 BST
NSE: Loaded 0 scripts for scanning.
Initiating SYN Stealth Scan at 11:19
[code]....
I wish to use the VNC server built in to the Ubuntu to easily access it from other computers on my local network. I need to skew the VNC Server port off of the normal 5900 to something else because I am using VNC to access several computers (sometimes simultaneously) so each VNC server needs to be set with a different port #. At this point it is all local subnet connections with no incoming internet access and I am not worried about security.
View 2 Replies View RelatedI would like to listen to a virtual serialport (dev/ttyACM0). I heard you can this with the terminal in Linux. But how? Does anyone know some commands?
View 2 Replies View RelatedI've killed apache via /etc/init.d/apache2 stop, but something is still listening on port 80:
Code:
root@www:/etc/apache2/sites-enabled# netstat -an | grep LISTEN | grep 80
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:8022 0.0.0.0:* LISTEN
unix 2 [ ACC ] STREAM LISTENING 5806 /var/run/mysqld/mysqld.sock
How do I find out that program this is?, or how to I stop it listening?
How can I set my server to listen at a different port for http access. I would like to use port 8080 (to circumnavigate isp blocks). Also can I do the same thing for sftp connections?
View 3 Replies View RelatedI was just wondering what I have to edit in order to get Maia Mailguard to listen on port 443 instead of port 80
right now I am logging on with [URL] but I would like to connect to [URL]
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 am new to Linux, moreso to CentOS, but I can definitely follow walk-throughs and tutorials easily enough.
I am installing a webserver for our small business and decided to go the postfix/dovecot route.
I installed everything based on the walkthrough on linuxmailcom and eve put squirrelmail on top, so users can access via webmail. I am able to send mail just fine, users/folders are setup and working as they should for sending, but I am unable to receive any mail. MX records have been updated to direct mail @mydomain to this mailserver machine. The problem I am having is with port 25... If I do 'telnet x.x.x.x 25' I get no response, just a timeout then back to command prompt. My other ports are fine, and I get the banner for each 110, 143, etc... all ports but 25 work internally and externally, forwarded.
I tried turning off firewall rules, and still, nothing from port 25. Should I try to have postfix listen on another port by editing its' master.cf, or is this is problem with my centOS/Linux instead. I didn't know where to go with this, so I thought the best place to start was here.
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 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)
[Code]....
configuring my postfix server to send mail over smtps port 465. My ISP (as is the case with many ISPs), is blocking outbound SMTP, so I need to configure postfix to relay my mail out through my ISPs SMTP servers.
I was able to get it to work with gmail, which uses port 587, by using SASL: [URL] but that configuration is less than ideal as gmail drops the "reply to" address so when people receive my email, it looks like it's from gmail instead of from my server.
If I use my ISP SMTP servers as a relay the "reply to" address is not stripped, but the relay uses ssl over port 465 instead of TLS. According to the SASL readme:
Quote:
Postfix does not deliver mail via TCP port 465 (the obsolete "wrappermode" protocol). See TLS_README for a solution that uses the "stunnel" command.
I've looked at the TLS_README and can't figure out what I need to do. how to configure this?
To launch easy tether I need to open 2 terminals and type some command, not all that hard, but I can I do this with one launcher? "Open Terminal and run "easytether enumerate", then "easytether connect". Once it says the connection is established, do not stop the running "easytether connect", open another Terminal and run "sudo dhclient easytether0". "
View 4 Replies View RelatedI currently have Fedora running on it's own hard drive and I have two other drives in the same workstation I want to setup as Raid 0. Is this possible and what tool can I use to accomplish this? I have a feeling I might have to reinstall the entire system to accomplish this ...
View 2 Replies View RelatedI'm a NOOB setting up Postfix but managed quite well by following the Ubuntu Server guide. I have managed to set it up using SSL but testing a mail client like thunderbird I can also connect to port 25 using no authentication. Connecting using SSL on port 465 by editing "master.cf" file works but 25 i still open.
1. How do I prevent clients to connect to port 25 without authentication?
2. I guess I have to have port 25 open in order to receive mail from the outside world?
Here is what i do: make clean make makefiles CCARGS='-DEF_CONFIG_DIR="/opt/product/postfix-2.6.5/etc"
-DEF_COMMAND_DIR="/opt/product/postfix-2.6.5"
-DEF_DAEMON_DIR="/opt/product/postfix-2.6.5/libexec"
-DEF_MAILQ_PATH="/opt/product/postfix-2.6.5/bin/mailq"
-DEF_DATA_DIR="/opt/product/postfix-2.6.5/lib"
-DEF_NEWALIAS_DIR="/opt/product/postfix-2.6.5/bin/newaliases"
[Code]...
make install then i got this error: postfix: fatal: chdir(/usr/libexec/postfix): No such file or directory make: *** [install] Error 1 I don't understand why it's checking the usr/libexec folder for the daemons although I've set the folder to /opt/product/postfix-2.6.5/libexec in the makefile. Here is also the cat of my makedefs.out:
[Code]....
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:
[Code].....
I bridged a connection using ettercap and have collected a few ips that I would like to block (IP Lag). Similar to what zone alarm and cain and abel accomplish in windows.I have tried adding the ip to iptables and tried using ufw to no avail.
View 9 Replies View RelatedHow to tell dhcpd to listen to ifcfg-bond0 ?
View 1 Replies View RelatedIn my Solaris tcp client server program, In server side I am checking the size of recv buffer, based on different listen queue size.
I was expecting this size to be increased due to the increase in receive queue size. why the value is same ?
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