Re: Forward specific port to another ip

[Andy Lego <legoandy@gmail.com>]

Hi again,

Ok, another thing I noticed. If I go to another system and issue the telnet:

telnet a.xx.com 8080
it just haings. So I tried:

iptables -t nat -F
iptables -t nat -A PREROUTING -p tcp --dport 8080 -j LOG --log-prefix
"WebProxy:"
iptables -t nat -A PREROUTING -p tcp --dport 8080 -j DNAT
--to-destination 192.168.1.220:80

And then I see:

Dec 27 13:48:34 andoria kernel: WebProxy:IN=eth0 OUT=
MAC=00:08:74:4f:f2:c9:00:07:e9:b1:6d:eb:08:00 SRC=192.168.1.197
DST=192.168.1.56 LEN=48 TOS=0x00 PREC=0x00 TTL=128 ID=52720 DF
PROTO=TCP SPT=3005 DPT=8080 WINDOW=65535 RES=0x00 SYN URGP=0

So, looks like the packets are forwarded. That said, looking at tcpdump output:

tcpdump -i eth0 port 8080

13:50:36.668387 IP 192.168.1.197.3007 > 192.168.1.56.8080: S
229587113:229587113(0) win 65535 <mss 1260,nop,nop,sackOK>

and no reply or forward.

Any clue?

Thank you.

Andy

On 12/27/05, Andy Lego <legoandy@gmail.com> wrote:
> Hi Edmundo,
>
> Looks like I am doing something wrong:
>
> root@andoria # iptables -t nat -A PREROUTING -p tcp --dport 8080 -j
> DNAT --to-destination 192.168.114.100:80
> root@andoria # telnet localhost 8080
> Trying 127.0.0.1...
> telnet: connect to address 127.0.0.1: Connection refused
> telnet: Unable to connect to remote host: Connection refused
> root@andoria # telnet 192.168.114.100 80
> Trying 192.168.114.100...
> Connected to a.xx.com (192.168.114.100).
> Escape character is '^]'.
> ^]
> telnet> close
> Connection closed.
>
> iptables -t nat -L
>                                                  ~
> Chain PREROUTING (policy ACCEPT)
> target     prot opt source               destination
> DNAT       tcp  --  anywhere             anywhere            tcp
> dpt:webcache to:192.168.114.100:80
>
> Is there anything else I should be doing?
>
> Thank you.
>
> Andy
>
> On 12/25/05, Edmundo Carmona <eantoranz@gmail.com> wrote:
> > that would be a DNAT rule on NAT PREROUTING, for starters (assuming
> > we're working on a.xx.com).
> >
> > iptables -t nat -A PREROUTING -p tcp --dport 8080 -j DNAT
> > --to-destination b.xx.com:80
> >
> > On 12/25/05, Andy Lego <legoandy@gmail.com> wrote:
> > > Hi,
> > >
> > > I would like to forward all requests that come to system a.xx.com at
> > > port 8080 to go to another system b.xx.com to port 80.
> > >
> > > For example, I am running a web server on system b.xx.com, but I want
> > > it to look like it is running on a.xx.com on different port.
> > >
> > > Also, I want to do this on a.xx.com only, without touching the
> > > firewall or b.xx.com.
> > >
> > > Any ideas?
> > >
> > > Thank you.
> > >
> > >   Andy
> > >
> > >
> >
>
>
> --
> http://legoandy.com
>


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