This topic is for advanced user. Normally it is not needed for the most XigmaNAS installations.
The FreeBSD Handbook describes “Static routes” as follows:
For one machine to be able to find another over a network, there must be a mechanism in place to describe how to get from one to the other. This is called routing. A “route” is a defined pair of addresses: a “destination” and a “gateway”. The pair indicates that if you are trying to get to this destination, communicate through this gateway.
For more information about “Static routes” see the FreeBSD Handbook - Chapter 31 Advanced Networking
At home I have 2 Internet connections ( 2 different ISP). So I use this feature to connect both networks ( via wlan). The effect is that my XigmaNAS server can access the Internet Gateway from the other Network.
This give me the possibility to use services on the other Network. For example currently i have mounted a harddisk from another box via iscsi to expand my storage.
Also the other Internet connection is faster so I can faster download files. In my case the XigmaNAS box is used to download and share virus definitions, the FreeBSD source and ports-tree and some other stuff.
As you see, you are able to manage the routes from here: