Create Table Sessions (
  session_id INT UNSIGNED NOT NULL AUTOINCREMENT,
  ip_address INT UNSIGNED NOT NULL,
  session_data TEXT NOT NULL,
  PRIMARY KEY (session_id),
  INDEX (ip_address)
) ENGINE=InnoDB

// Insert a new dummy record
INSERT INTO Sessions VALUES (NULL, INET_ATON('192.168.0.2'), 'some session data');

//Find all sessions coming from a local subnet
SELECT
  sessin_id,
  ip_address as ip_raw,
  INET_NTOA(ip_address) as ip,
  session_data
FROM Sessions
WHERE ip_address
BETWEEN INET_ATON('192.168.0.1')
AND INET_ATON('192.168.0.255')

Saving the IP as Int we save a lot of space and permit do beautibul selects

Create Table Sessions

mysql, ip

MySQL