Re: Port forwarding how ??

[Jeff Largent <jlargent@imagelinks.com>]

You also need a POSTROUTING for the return.
iptables -A POSTROUTING -t nat -p tcp -s 192.168.0.14 --sport 3306 -j SNAT 
--to-source <ip of host doing the original port forward>

If you don't have this the forwarding host will gladly forward the message
with the 192.168.0.14 ip, that you have no way of directly contacting.

Jeff

Scott Taylor wrote:
> Please make your replies to the list.
> 
> At 04:15 PM 1/14/03, you wrote:
> 
>> Ok,
>> And what about this ?
>> ( I read this on that link you provided to me )
>>
>> iptables -A FORWARD -p tcp --dport 3306 -j ACCEPT
>> iptables -A PREROUTING -t nat -p tcp --dport 3306 -j DNAT --to
>> 192.168.0.14:3306
>>
>> When i try to connect on server where i entered rules i writed above, I
>> get the following:
>>
>> [root@gatekeeper root]# telnet 192.168.0.13 3306
>> Trying 192.168.0.13...
>>
>> [root@gatekeeper root]#
>>
>> 192.168.0.13 = server where i entered the iptables ... which i need to
>> redirect me to 192.168.0.14
>> 192.168.0.14 = server running mysql ( port 3306 ).
>>
>>
>> On Wed, 2003-01-15 at 00:44, Scott Taylor wrote:
>> > At 03:16 PM 1/14/03, you wrote:
>> > >Anyone configured port forwarding that worked ?
>> >
>> > Yes.
>> >
>> >
>> > >I was reading lot's of howto documents, but i was unable to configure
>> > >that thing.
>> > >
>> > >
>> > >iptables -t nat -A PREROUTING -i $OUTSIDE -p tcp --dport 3306 -j DNAT
>> > >--to 192.168.0.14
>> > >
>> > >This is how i configured it .. but it doesn't work .. anyone have any
>> > >idea or something .. ?
>> >
>> > That alone is not going to do a lot for you.
>> >
>> > Here is a HowTo that should help:
>> > http://tldp.org/HOWTO/IP-Masquerade-HOWTO/index.html
>> >
>> > Then snoop around David's site and read the TrinityOS docs:
>> > http://www.ecst.csuchico.edu/~dranch/LINUX/index-linux.html
>> >
>> > -
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> 
> 
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-- 
Jeff Largent                   ImageLinks, Inc.
Sr System Admin                Melbourne, Fl 32935
(321) 253-0011                 fax:(321) 253-5559