You should be able to connect to your switch from anywhere you want, unless you use asymmetric routing in the network your switch is directly connected to. Mask and gateway are suddenly not required. The following quote explains how it works (taken from here, but can also be found here and here):
Note: SwOS uses a simple algorithm to ensure TCP/IP communication - it just replies to the same IP and MAC address packet came from. This way there is no need for Default Gateway on the device itself.
You can also check out this post of mine.