LinuxQuestions.org
View the Most Wanted LQ Wiki articles.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices

Reply
 
Search this Thread
Old 03-22-2005, 11:25 AM   #1
capbob
LQ Newbie
 
Registered: Mar 2005
Posts: 3

Rep: Reputation: 0
Can forward port 80 but not others


Hi, I've got a linux server set up as an internet gateway with two windows xp machines connected to it via a switch. I've been trying to forward ports 3389 and 4899 to one of the xp machines but have been unable to get it to work. I have however, successfullu forwarded port 80 to the same machine. Here are my firewall rules reguarding the ports.

$IPCHAINS -A input -i $EXTIF -p tcp -s 0.0.0.0/0 -d $EXTIP 80 -j ACCEPT
$IPCHAINS -A input -i $EXTIF -p tcp -s 0.0.0.0/0 -d $EXTIP 3389 -j ACCEPT
$IPCHAINS -A input -i $EXTIF -p tcp -s 0.0.0.0/0 -d $EXTIP 4899 -j ACCEPT

$IPCHAINS -A output -i $EXTIF -p tcp -s $EXTIP 80 -d 0.0.0.0/0 -j ACCEPT
$IPCHAINS -A output -i $EXTIF -p tcp -s $EXTIP 3389 -d 0.0.0.0/0 -j ACCEPT
$IPCHAINS -A output -i $EXTIF -p tcp -s $EXTIP 4899 -d 0.0.0.0/0 -j ACCEPT

/usr/sbin/ipmasqadm portfw -a -P tcp -L $EXTIP 3389 -R $PORTFWIP 3389
/usr/sbin/ipmasqadm portfw -a -P tcp -L $EXTIP 4489 -R $PORTFWIP 4899

Any ideas why port 80 would work but the other 2 won't?
 
Old 03-22-2005, 12:36 PM   #2
Technoslave
Member
 
Registered: Dec 2003
Location: Northern VA
Posts: 493

Rep: Reputation: 30
Straight from my website, check the link below, you'll find a diamond in the rough every now and again ... ok, actually, I write this junk up on my website because I have a horrible memory and I need reference to it:

It's always a pain in the ass for me to remember how to do this, I always forget a step and add an extra step that matters not.

So, here's the example of port forwarding using iptables.

I have an internal server on port 10.0.0.2, running apache on port 80. I want to be able to reach it via port 81 from my gateway computer.

/sbin/iptables -t nat -I PREROUTING -p tcp -d 209.190.200.143 --dport 81 -j DNAT --to 10.0.0.2:80

That's the part I always remember.

/sbin/iptables -I FORWARD -p tcp -d 10.0.0.2 --dport 80 -j ACCEPT

That's the part I always forget.

Anyway, port forwarding in two easy steps.

Hopefully you can extrapolate what you need from the above by changing the port numbers, etc.
 
Old 03-29-2005, 11:52 AM   #3
capbob
LQ Newbie
 
Registered: Mar 2005
Posts: 3

Original Poster
Rep: Reputation: 0
Sorry it's taken me so long to reply.

I've already gotten port forwarding to work, just not on the ports that I want it to forward. I've forwarded port 80 successfully but haven't had any success with 3389 or 4899. Also I have to use ipchains, not iptables.
 
Old 03-30-2005, 02:21 PM   #4
Technoslave
Member
 
Registered: Dec 2003
Location: Northern VA
Posts: 493

Rep: Reputation: 30
*blush* sorry, didn't even see that it was ipchains, my apologies. However, if you got 80 to work, 80 is just a number, there's nothing special about it, the other numbers you put in there should work as well.

What you've given above, minus forwarding port 80 line ( don't see that, but I'm guessing it's the same. ) Sorry, don't know what to tell you.
 
Old 05-20-2005, 07:02 PM   #5
capbob
LQ Newbie
 
Registered: Mar 2005
Posts: 3

Original Poster
Rep: Reputation: 0
I recently upgraded my kernel to 2.6 so I can use iptables now. I'm still having the same exact problem though. Here's my entire firewall script. Anyone see any problems?

http://panthers.pnc.edu/rjohns01/firewall2.txt
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Port Forward prbspfc Linux - Networking 9 03-24-2004 06:00 AM
A way to forward an IP/Port to another system's IP/Port astroboy5714 Linux - Networking 6 01-26-2004 05:45 PM
port forward help please indy317 Linux - Networking 2 07-18-2003 02:21 PM
Port forward help please hanxuerui Linux - Networking 6 05-05-2003 01:20 PM
Forward port port 80 to lan web server dulaus Linux - Networking 9 10-04-2002 03:45 AM


All times are GMT -5. The time now is 11:30 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration