How to add route to Buffalo router

Question

I'm trying to understand what I can make use with this feature on my Buffalo WHR-HP-GN router. Using the User Friendly Firmware, I've clicked on the Internet / LAN -> Route menu, and am presented with the following:
Add Routing
Destination Address:
Gateway:
Metric:

However, when I attempted to add the following:
Destination Address: 192.168.60.4
Gateway: 192.168.20.22
Metric: 15 (This is the default)

I'm given the following:
ERROR: Destination Address description: IP Address is not valid as network address

The reason I entered the above is because I have the following setup:

Internet -> Buffalo Router -> 192.168.20.1/24  
                           -> Another Router (192.168.20.22) -> 192.168.60.1/24  
                                                             -> Device (192.168.60.4)

Answer 1

If you want to add route to single host, you should choose Destination Address 192.168.60.4 and Subnet Mask 255.255.255.255

If you want to add the whole 192.168.60.X/24 network, use the very first address in subnet as "network address", so the right combination is [192.168.60.0 & 255.255.255.0]