Problem using IP functions

Hi,

I'm having trouble using the host() and netmask() functions within a select
query. For some reason, the following query returns 1 row:

ipdb=> select id, subnet_number from subnet where subnet_number =
'216.46.13.0';
id | subnet_number
----+---------------
96 | 216.46.13.0
(1 row)

Yet, if I replace the ip string literal with host('216.46.13.0/24'), I get
no results. ie:

ipdb=> select id, subnet_number from subnet where subnet_number =
host('216.46.13.0/24');

id | subnet_number
----+---------------
(0 rows)

Even though host('216.46.13.0/24') evaluates to 216.46.13.0

ipdb=> select host('216.46.13.0/24');
host
-------------
216.46.13.0
(1 row)

The subnet_number column is a varchar(16) which I assume you can compare
with a text data type, which is what host() returns. Just to be sure, I
tried casting everything to type text, but that didn't do the trick.

ipdb=> select texteq(host('216.46.13.0/24')::text, '216.46.13.0'::text);
texteq
--------
f
(1 row)

Any insight would be greatly appreciated.

Marc