This optional field allows you to specify a static IP address for that
user. You should only enter something in here if you want that user to
always get the same IP address when they log in. If you don't enter
anything in here (i.e. leave it blank) then the user will be allocated an
IP address from the normal address pool. It will usually be different each
time they log in. You can see which IP address a user gets by looking at
their usage page.
Static IP Address must be entered as a dotted IP address like these
examples: