Connecting to an external database with pgAdmin III
This line:


 host    all             all             192.168.0.0/24          md5


will let through connections from IPs matching 192.168.0.X where X is any byte.

The IP address of your error message being 192.168.108.161, it does not match this pattern because 108 is not 0.

To enable addresses like 192.168.X.Y, you'd need a /16 instead of /24 meaning that the first 16 bits only are fixed.

Like this:


 host    all             all             192.168.0.0/16          md5


Don't forget to reload Postgresql. From the official docs, use pg_ctl reload. If that doesn't work, then there are other ways to do it listed in this question.