acl problem

Hello,

I have really small network (about 10 users). But totally I have about
50 users.

I wanted to restrict usage of squid as follows:

---
acl all src 128.0.0.16-128.0.0.25/255.255.0.0
acl none src 0.0.0.0/0.0.0.0
http_access allow all
http_access deny none
---
I want only that machines which have an IP between 128.0.0.16 and
128.0.0.25 can use proxy.
I tried to use squid from a machine that have an IP of 128.0.0.31 and it
used the proxy server.
I'm not sure if I did everything all right. I have FreeBSD 3.3 and,
squid 2.2STABLE5 version (compiled with --prefix=/squid parameter only).
Do you have any ideas?
Regards,
-- 
Ertan Kucukoglu
ertank@ozlerplastik.com