If you use username and passwords for your externel users, this means you have protected items on your server. This could not be accessed by no way without a login.
So, if you want that for your local users not to be necessary to press the loginbutton and fill out the form with username and password, i suggest the following.
Create an account for your local users, for example username:
local and password:
net. All local users can use the same account.
Then, instead of accessing with
http://192.168.nn.nn:port/ have them access with
http://local:net@192.168.nn.nn:port/ that does then login directly.
To avoid that users from outside use this username and password, you can put in the [special:begin]section the following macro:
{.if |{.and|{.not|{.match address|192.168.1.2-192.168.1.255|%ip%.}.}|%user%=local.}|{:{.disconnect.}:}.}
