Updating cidr column with network operator

Hi SQLers,

I have a fk from address to network and try to update the foreign key
column to point at the network, "it belongs to":

CREATE TABLE network (
id cidr PRIMARY KEY , -- 'PK, ,IPv4/6 Network address'
)

CREATE TABLE address (
id inet PRIMARY KEY , -- 'PK of IPv4/6 host address'
network cidr NOT NULL -- 'FK to Network table'
REFERENCES network ON DELETE CASCADE ON UPDATE
CASCADE
)

I tried (using the WHERE clause to eliminate the addresses were no
corresponding net exists):
UPDATE address
SET network = (SELECT N.id WHERE A.id << N.id)
FROM address A, network N
WHERE A.id << N.id;

But this ended up with all network columns pointing at the same net
(-:).
Any help would be appreciated.

Axel
Axel Rau, Frankfurt, Germany +49-69-951418-0