Port forwarding problem

[JimPletcher]

Small Business SBS2000 using IIS for internal HTTP and FTP.
Zyxel 645 router (like NetGear 311).
Port forwarding on router set to direct HTTP & FTP ports to IIS server.
Can access IIS server (HTTP & FTP) fine from inside (using local IP).
Cannot access either from outside using public IP.
FTP returns asccess denied, HTTP returns 404 error.

Tried using standard ports (20, 21 & 80) and non-standard ports (27015 etc)at both IIS & router.

I must be missing something basic here. Anyone have any ideas?

 

[ChrisAC]

Are you seeing the connection attempts on the IIS server? What do the logs shows on the router?

Chris.


**********************
Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
**********************

 

[JimPletcher]

Thanks for the response, I still haven't been able to fix this.

No connection attempts show on the IIS server.
Nothing (other than local telnet connections)in the Router Error log.
Router Syslog not activated, (not too sure how)

 

[JimPletcher]

FTP logs on IIS server show all connections made from inside (local IP), but nothing from the router.

No rules on the router prevent traffic on the ports being used.

 

[ChrisAC]

If the IIS server is not seeing any connections attempts then it sounds like the port forwarding isn't working on the router.

Chris.


**********************
Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
**********************

 

[JimPletcher]

Thanks again for the response Chris!

There's no doubt that the port requests aren't being forwarded, but this is the second router (of the same type).

Its unlikely that two consecutive routers (with different firmware revisions) would be bad. It is more likely that I'm doing something wrong.

Testing the ports (with Shields Up (from

https://grc.com/x/ne.dll?bh0bkyd2

)shows open ports when the IIS server running .

With the IIS server not on-line, the test shows "stealth" ports.

When attempting to FTP from outside (with WsFTP), a userid is requested. Any userid (including a blank one) results in a "connection" refused message.

FTP at the command prompt results in a "connect :Unknown error number" message.