Routing / Port forwarding question

Hello

I don't know how to route or to forward a port.

On my ADSL ZyXel Prestige 650 router I added the following
port in the SUA/NAT Server

Start port End Adresse IP
8081 8081 192.168.90.11

I thought that the url http://xxx.xxx.xxx.xxx:8081 would
now route me to the LAN IP 192.168.90.11

But this to not work. If use the same url without port then
the router show me the login windows from the ZyXel Router.

If in enter the following port in the SUA/NAT Server:

Start port End Adresse IP
80 80 192.168.90.11

then I can access to the IP 192.168.90.11 and this also
without port no.!

My question: How do I have to configure the router that I
can access to the LAN IP 192.168.90.11 with a port and to
the router without port?

Many thanks in advance for your help.

Otto

"Otto" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hello
>
> I don't know how to route or to forward a port.
>
> On my ADSL ZyXel Prestige 650 router I added the following
> port in the SUA/NAT Server
>
> Start port End Adresse IP
> 8081 8081 192.168.90.11
>
> I thought that the url http://xxx.xxx.xxx.xxx:8081 would
> now route me to the LAN IP 192.168.90.11

This maybe a stupid question but do you have a computer on the LAN with a
"Static IP Address" of 192.168.90.11? If you don't use a static address then
each time a computer connects to the LAN the local DHCP server, your router
most likely, just hands out the next available address. Thus the computer
may not always get the same IP address each time and the port forwarding
will not forward traffic to the right computer.

The next issue is the above address is only valid inside of your LAN and
can't be reached from the Internet. The address that has to be used is the
address assigned to the router by your Internet Service provider. The NAT
function in the router, using the port forwarding feature, takes care of the
address translation so the machine is reachable from outside, i.e. from the
Internet.

One more thing, if the address isn't a static address from your Internet
Service Provider then the setup gets a bit more complicated. You have to use
a service that allows your computer to update a database on a DNS server
service with your current IP address assigned to your router, then use the
name you picked on that service to refer to your computer. This name on the
DNS server looks up yor most current IP address and sends that to whoever
wants to access your machine like any other DNS look up would do.

http://www.dyndns.org/
http://www.tzo.org/

Both of the above are free DNS server services.

And lastly you have to have a service running on the machine that can handle
the traffic directed to it due to port forwarding. I'm a bit confused by
what you're trying to do but it seems like you're trying to run a WEB server
on a computer on your LAN that is reachable from the Internet. The standard
port for HTTP WEB servers by the way is 80.


--
Leland C. Scott
KC8LDO

Wireless Network
Mobile computing
on the go brought
to you by Micro$oft

Many thanks four your quick answer.

> This maybe a stupid question but do you have a computer on the LAN with a
> "Static IP Address" of 192.168.90.11?
>
Yes, the IP 192.168.90.11 is static. It's a small WebServer with Relay's (no
PC)

> The next issue is the above address is only valid inside of your LAN and
> can't be reached from the Internet.
>
I understand that.

I also know the IP from the WAN to access to the ZyXel Router.
My question was:
How can I access different LAN IP from the same WAN IP. Actually I used the
port Forwarding from my Router and it work well.
In the SUA/NAT table I add the following values:

Start port End Adresse IP
80 80 192.168.90.11

but if I to the following:
8081 8081 192.168.90.11
8082 8082 192.168.90.12
nothing work

Could be that the MicroWebserver on the IP 192.168.90.11 need the port 80. I
don't really know.

Regards

Otto

"Otto" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> My question was:
> How can I access different LAN IP from the same WAN IP. Actually I used
the
> port Forwarding from my Router and it work well.
> In the SUA/NAT table I add the following values:
>
> Start port End Adresse IP
> 80 80 192.168.90.11

That seems OK.

>
> but if I to the following:
> 8081 8081 192.168.90.11
> 8082 8082 192.168.90.12
> nothing work

Not surprising. The WEB server needs to use port 80, which is the standard
port for HTTP, to work. When you changed the port you forwarded to 8081 Web
browsers can't connect to the server because they are trying to use the
"well known" port of 80, which you didn't forward. You can't just forward
just any port to a server and expect it to work. If the Web server is not
configured to use the non standard port you forward it's not going to work.
If you do configure the server to use a non standard port, use lets say port
8081, then you MUST use a URL of the following form:

www.YourWebSite:8081 or http://YourWebSite:8081

Note the colon before the 8081. This tells the web browser to use port 8081
instead of the standard port of 80 when connecting to the web server. If you
forget to do this then the web browser will use the default standard port of
80 and thus fail to connect.

I've done the exact same thing with a private FTP server running behind my
NAT-SPI router/firewall on my home LAN. The FTP server is setup to use non
standard ports, it really cut down on the hacking attempts, and had to
forward the non standard ports in the router setup. To access my FTP server
I have to use an address like the following:

ftp://MyFtpServer:Non-Standard-Port-Number

The standard FTP ports are 21 and 20, which I'm not using. If I don't add
the colon port number part after the address I can't connect, period.

Hope this helps.

--
Leland C. Scott
KC8LDO

Wireless Network
Mobile computing
on the go brought
to you by Micro$oft

> Hope this helps.
>
Yes. Many thanks four your quick answer.

Otto