Web Publishing Service on Zuxel NAS326 and Port Forwarding on Netgear Router

> [...] I have no experince in Port Forwarding and what it does. [...]

   That will need to change.  Port forwarding is what the router does to
deal with a message which arrives at its WAN/Internet port from the
outside world.  Your ISP has assigned one (external) IP address to your
whole installation; either you or your router has assigned an entirely
different (LAN) IP address to each device on your LAN.

   If someone in the outside world wants to send a message to a device
on your LAN, all he can do is send it to your router.  How, then, does
the router know what to do with that message?  To which of your devices
(if any) should it forward that message?

   A port-forwarding rule is what tells the router what to do with such
a message.

> [...] http://[server-name:5000]/MyWeb/Public [...]

   More precisely:

      http://[server-name]:5000/MyWeb/Public [...]

   Note that your "[server-name]" could also be your external IP
address instead of a DNS name.

   That "5000" is the relevant port number.  You can think of it as like
an apartment number after a street address (IP address).  In this case,
you'd want a port-forwarding rule like:

      Service Type: TCP+UDP
      External port range: 5000
      Internal port range: 5000
      Server IP Address: <LAN_IP_address_of_NAS>

   That implies that the NAS device needs a fixed LAN IP address, which can
be arranged at ADVANCED > Setup LAN Setup : Address Reservation.

   With such a rule in effect, when a message destined for port 5000
arrives at your router's WAN/Internet port, the router will forward it
to the device at <LAN_IP_address_of_NAS>.  When that device sends a
reply to that message, the router will handle the reply, ensuring that
it returns to the outside-world device which sent the original message.

   It's important that the IP address of the WAN/Internet on your router
match your public (external) IP address. If there's another router
between yours and the Internet (which could be a second router at your
site, or at your ISP's site) then you can expect problems.

   As you might guess, you could specify different external and internal
port numbers in your port-forwarding rule.  The external port number is
what is used in the outside world; the internal port number is what is
used on your LAN.  So, for example, if you had a second NAS device, you
could create a rule like:

      Service Type: TCP+UDP
      External port range: 5001
      Internal port range: 5000
      Server IP Address: <LAN_IP_address_of_NAS-2>

Then, a URL like the following would reach "NAS-2":

      http://[server-name]:5001/MyWeb/Public [...]

   On your LAN, NAS-2 would still use port 5000, but, because of that
port-forwarding rule, it would be seen at port 5001 from the outside
world.