Apologies if I oversimplify anything below, but I do not know your network skills. I do not have the router, but I downloaded the manual from ASUS.. may be slightly different from the hardcopy you received with the device
I am also assuming that the static IP address has not yet been implemented in the router, as you say the provider doesn't know how to do it in your router (but unless they are a hopeless ISP, they will know the basic steps that have to be accomplished)
A static IP address is only of interest to you if you wish to offer resources from your Local Area Network (LAN) to the users on the Internet. Basically, it gives an IP address that users (and hackers) can use to go direct to your 'service', ie a public web server, webcams or similar things.
If you do not have any desire or requirement to offer these, then simply file the IP address for future use, and continue as you are.
There is another way to achieve the same effect without using a static IP address, and that is to use DDNS which is described in your manual, and does not need any coordination with the ISP.
OK, if you are still reading, then maybe you do want to use the static IP address;)
As JustinThyme says, the IP address is installed on the WAN interface of the router, however I would disagree that it is simply a matter of reconfiguring from dhcp to static and adding the static IP address. Reason for saying this is that this has to be closely coordinated with the provider, as he has to make similar changes to the 'other' side of the connection (ie, to the WAN router that you are connected to) AT THE SAME TIME, else the network routing will not work.
Assuming you can coordinate with the provider, then you do as JustinThyme say, configure the wan interface to use static IP addresses, define the IP address, network and gateway address and the DNS server (the provider must provide all four values, although you could also use a public DNS server such as googles 8.8.8.8).
So, in section 4.5.1 point 2, you would change WAN Connection Type to Static IP,...... and here the manual fails as it assumes you chose Automatic IP, and so does not describe the screens which appear next. :mad: I found
this faq which should be similar.
So, you can now code in the static IP address, network (probably 255.255.255.252) the gateway and also the provider recommended DNS address
If the provider has made his changes on the other side of the cable, you should now get a network connection, and your router is known on the outside by the static IP address.
You now need to decided what to do about security, and what devices to expose...
Hope this helps