Port Forwarding help

karelvdm · 11-22-2006, 03:07 AM

Amitsharma spoke about "port-forwarding with PREROUTING+POSTROUTING"
If I could give that a try?
What would the commands look like?
The setup;
Freebsd box
rl0 is the lan NIC with ip 192.168.45.146
rl1 is the wan NIC with ip 10.0.0.1 , but the ip I use to connect to the freebsd box
is 41.241.*.* (via adsl).
Connect to freebsd box via port 4899 and gets forwarded to the unix server;
ip 192.168.45.1 on port 23.
The unix server's gateway is their satelcom router's ip; 192.168.45.10.

amitsharma_26 · 11-24-2006, 11:05 AM

Hi again dear, (sorry for delayed reply)
You know what; it seems as these both boxes(192.168.45.1 & *.146) fall under a same LAN; unix server having some other default gateway would'nt stand for much problem i think.(i am still not sure because of non-availabilty of routing tables of 192.168.45.1 box)

Anwyays you can try out these below mentioned PRE-ROUTING + POSTROUTING commands. And karelvdm; as i am also not sure whether your adsl modem is being forwarding those 41.241.*.* packets to your box 10.0.0.1 ethernet or is it doing NATing, so in the first below mentioned PREROUTING rule, if it doesnt work, you should change the -d 41.241.*.* to -d 10.0.0.1

Code:

iptables -t nat -A PREROUTING -d 41.241.*.* -p tcp --dport 4899 -j DNAT --to 192.168.45.1:23

&

Code:

iptables -t nat -A POSTROUTING -d 192.168.45.1 -j SNAT --to 192.168.45.146

Lets hope that it will work your problem out.

karelvdm · 11-27-2006, 03:38 AM

Hey Amitsharma

When trying:
iptables -t nat -A PREROUTING -d 10.0.0.1 -p tcp --dport 4899 -j DNAT --to 192.168.45.1:23

I get
"iptables: Command not found"

amitsharma_26 · 11-27-2006, 05:51 AM

Quote:

Originally Posted by karelvdm

I get
"iptables: Command not found"

It seems that either iptables is not installed or the path variable has not been updated for an alternate location installation.

Like the way we have

Code:

rpm -qi iptables

for telling whether queried application is installed or not in REDHAT (afaik), you must be having some way to check this at your SLED10 distro as well.

Why dont you install iptables either downloading from its website or from the cds of your distro.

karelvdm · 11-27-2006, 08:35 AM

Hey Amitsharma,

My FreeBSD 6.1 box doesn't use iptables, it usses ipfw.

Browsing through the FreeBSD forums to find out what the commands would be
for my scenario.

I'll let U know how it goes.
Thanx a mil for the help so far!!!!!

karelvdm · 11-28-2006, 09:19 AM

Hey Amitsharma,

Might be able to get it to work.......
Connect via a vpn connection to the freebsd box with user authentication,
then telnet to the server(192.168.45.1).
The client access software that the cleint uses creates a telnet session.
Busy setting up the vpn connection. Let U know how it goes!

amitsharma_26 · 11-28-2006, 09:43 AM

I like ya sign, it tells me about ya attitude. It seems you are doing the job same way you have mentioned; Trial & ERROR & keeeeep trying until you get the results.

Karelvdm, You are doing a good job. Keep it UP & yea stay me updated.

karelvdm · 12-01-2006, 12:06 AM

Amitsharma

Been a bit busy lately.....

It works!!!!!!!
Now I want to set up a Suse box with VPN.
I prefer Linux to FreeBSD.
My boss has a friend that is a guru on FreeBSD, he greated the vpn the FreeBSD box after I pointed them into the right direction, but they don't want to show me how, so now I'm gonna setup my Suse box and show them......after I'm finished with my Trixbox.