How to match an ip address in mysql?

You're going to need to use REGEXP to match the IP address dotted quad pattern.

SELECT *
FROM yourtable
WHERE 
  thecolumn REGEXP '^[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}$'

Technically, this will match values that are not valid IP addresses, like 999.999.999.999, but that may not be important. What is important, is fixing your data such that IP addresses are stored in their own column separate from whatever other data you have in here. It is almost always a bad idea to mix data types in one column.

mysql> SELECT '9876543210' REGEXP '^[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}$';
+---------------------------------------------------------------------------+
| '9876543210' REGEXP '^[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}$' |
+---------------------------------------------------------------------------+
|                                                                         0 |
+---------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT '987.654.321.0' REGEXP '^[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}$';
+------------------------------------------------------------------------------+
| '987.654.321.0' REGEXP '^[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}$' |
+------------------------------------------------------------------------------+
|                                                                            1 |
+------------------------------------------------------------------------------+

Another method is to attempt to convert the IP address to a long integer via MySQL's INET_ATON() function. An invalid address will return NULL.

This method is likely to be more efficient than the regular expression.

You may embed it in a WHERE condition like: WHERE INET_ATON(thecolumn) IS NOT NULL

SELECT INET_ATON('127.0.0.1');
+------------------------+
| INET_ATON('127.0.0.1') |
+------------------------+
|             2130706433 |
+------------------------+

SELECT INET_ATON('notes');
+--------------------+
| INET_ATON('notes') |
+--------------------+
|               NULL |
+--------------------+

SELECT INET_ATON('56.99.9999.44');
+----------------------------+
| INET_ATON('56.99.9999.44') |
+----------------------------+
|                       NULL |
+----------------------------+

IS_IPV4() is a native mysql function that lets you check whether a value is a valid IP Version 4.

SELECT *
FROM ip_containing_table
WHERE IS_IPV4(ip_containing_column);

I don't have data, but I reckon that this must be the most solid and efficient way to do this.

There are also similar native functions that check for IP Version 6 etc.