SQL query that shows the number of total and allocated IPs for each pool that exists in radippool table

pool.sql

SELECT 
  pool_name,
  COUNT(*) AS total,
  (SELECT 
    COUNT(*) 
  FROM
    radius.radippool r2 
  WHERE r1.pool_name = r2.pool_name 
    AND NASIPAddress <> '' 
  GROUP BY pool_name) AS allocated 
FROM
  radius.radippool r1 
GROUP BY pool_name
ORDER BY pool_name