The internet box is set to route all incoming traffic to the Debian host (DMZ).
Then the Debian host is set to accept certain packets and forward others to the windows hosts. It's all based on the port number:
port 22 accepted
port 80 accepted
port 59032 forwarded to 192.168.1.32:5900
port 59033 forwarded to 192.168.1.33:5900
port 59034 forwarded to 192.168.1.34:5900
That allows me to ssh and web into my Debian host and to vnc into my Windows host from the outside world.
This is done by using iptables with the following rules:
The Debian host is happy receiving connections from the outside world.
But VNC on Windows would block packets if they are not from 192.168.1.0/24.
I could remove that restriction on the Windows host but NO, that's not what I want to do. So I'm using one more rule for iptables:
That way, the Windows host believe that the VNC connection is comming from the local server.
For future improvement reasons, I would rather masquerade only certain packets. So my idea is to do something in the nat.PREROUTING chain so that the nat.POSTROUTING chain will be able to tell whether a packet should be masqueraded or not.
My Device is connected to eth1 interface of the host and eth0 is connected to network.
Now when I am pinging google.com from device after executing below commands on host
sudo iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE
sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
I am... (0 Replies)
I am using nullmailer on Ubuntu Linux to relay mails however when I send email or through cron it appear as
root@myhostname.domain.com instead of root@domain.com
How do I configure nullmailer so the email send appear as from root@domain.com? (0 Replies)
edit: SOLVED - see below for solution
Hi there,
I've inherited a gob of Linux hosts and so am learning linux from the bottom of the deep end of the pool (gotta say I'm warming up to Linux though - it's not half bad)
Right now iptables is confusing me and I could use some pointers as to how... (0 Replies)
I'm trying to configure sendmail masquerading and it seems like I'm having a problem with m4.
My main problem is that internally generated emails are showing up externally as originating from: internal_user@internal1.mydomain.com.
internal1.mydomain.com doesn't resolve publicly, nor should it.... (1 Reply)
Hi,
Please tell me what is sendmail masquarade and what is the use of it?
Its pretty confusing :eek:..
Is it all about like when mail is sent from sender to receiver, the receiver cannot see the hostname/internal username of sender..
And I found they constitute various classes like class... (0 Replies)
Hello!
I have the following problem with iptables in Debian 6:
My server works as a router and it needs to log server external IP+port for all outgoing connections.
But after command SNAT or MASQUERADE traffic is "lost".
I mean no following rules can catch those traffic.
Everything looks... (0 Replies)
Hi,
I'm brand new here and looking for a solution:
I'm using mail or mailx. The default reply address is «myshortusername@mylongusername.local» which makes absolutely no sense for anybody receiving my emails.
But how do I change it? There seem to be many solutions but none for Mac OS X.... (0 Replies)
I have a SCO 5.06 box running sendmail 8.11. I have set up sendmail to masquerade the domainname as bar.com.
ie in the sendmail.cf file the directive
DMbar.com is set.
When I send mail using mail/mailx, it appends the local hostname "foo" to the masquerade address and inserts this into... (1 Reply)
Greetings to all.
My new firewall is giving me one hell of a problem.
I'm running iptables and masquerading my intranet
thru NAT. But here is the problem. Whenever I try
to FTP to a server outside of my lan I get a 500
illegal port error.
I've come to the conclusion that NAT is... (2 Replies)