Anyhow…you are also confusing storing an address with storing a network specification. A network specification is what has a bitmask length. If, as you say, you’re looking for specific hosts in a table, it’s either there, or it’s not; or it is between two values where you can find the minimum and maximum address values given an address and a bitmask, and query for (valu >= min and valu <=max). In other words, you should be doing the masking BEFORE any query.

If a single integer data type isn't big enough, your best bet for lookup/indexing efficiency is probably normalization of all the addresses, filling in the missing zeroes from the compressed notations.

An index on the addresses will presumably help. Yes, it probably makes sense also to store the bitmask lengths as well with each address, just that forming any aggregation of the two (such as a unique key or index on both the address and the mask) is rather unlikely methinks to be useful. It also seems rather less than useful above to use bitmask length as a key.

Heck…I'd think the best example of IPv6 storage and lookup efficiency could be found in the Linux or *BSD kernel sources where the routing tables are maintained and accessed. In essence, that code must make decisions on which table entry to use thousands of times every second in some cases.

mysql> SELECT CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,7) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,6) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,5) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,4) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,3) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,2) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,1) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,0) AS DECIMAL(39,0));
+—————————————————————————————————————————————————————————————————————————————————————–+
| CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,7) AS DECIMAL(39,0)) +
CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,6) AS DECIMAL(39,0)) +
CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,5) AS DECIMAL(39,0)) +
CAST(CONV |
+—————————————————————————————————————————————————————————————————————————————————————–+
| 340209681578175878893739963388222212325 |
+—————————————————————————————————————————————————————————————————————————————————————–+
1 row in set (0.00 sec)

mysql> SELECT CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,7) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,6) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,5) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,4) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,3) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,2) AS DECIMAL(39,0)) +
-> CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,1) AS DECIMAL(39,0)) +
-> CAST(CONV(‘fffe’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,0) AS DECIMAL(39,0));
+—————————————————————————————————————————————————————————————————————————————————————–+
| CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,7) AS DECIMAL(39,0)) +
CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,6) AS DECIMAL(39,0)) +
CAST(CONV(‘ffff’,16,10) AS DECIMAL(39,0)) * CAST(POW(65534,5) AS DECIMAL(39,0)) +
CAST(CONV |
+—————————————————————————————————————————————————————————————————————————————————————–+
| 340209681578175878893739963388222212324 |
+—————————————————————————————————————————————————————————————————————————————————————–+
1 row in set (0.00 sec)

mysql> Insert into address set ip= CONV(‘ffff’, 16, 10) * POW(65535, 7) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 6) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 5) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 4) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 3) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 2) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 1) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 0);

Query OK, 1 row affected, 1 warning (0.07 sec)

mysql> Insert into address set ip= CONV(‘ffff’, 16, 10) * POW(65535, 7) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 6) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 5) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 4) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 3) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 2) +
-> CONV(‘ffff’, 16, 10) * POW(65535, 1) +
->
-> CONV(‘fffe’, 16, 10) * POW(65535, 0);
Query OK, 1 row affected, 1 warning (0.00 sec)

mysql> select * from address;
+—-+—————————————–+
| id | ip |
+—-+—————————————–+
| 10 | 340246022585899900000000000000000000000 |
| 11 | 340246022585899900000000000000000000000 |
+—-+—————————————–+
2 rows in set (0.00 sec)

Question:
What’s wrong with this picture?
Answer:
The calculated values are identical, but they are not from the same IP. In fact the values inserted are not the correct decimal representation. This is due to MySQL losing precision in the POW calculation.

This is why:

mysql> select POW(65535, 7);
+——————–+
| POW(65535, 7) |
+——————–+
| 5.191742286784e+33 |
+——————–+
1 row in set (0.00 sec)

So, DECIMAL(39) will work great for storing, and even does good on math such as where ip > value1 and ip < value2. Just have to do the IPv6 to decimal mathematics outside of MySQL.

If someone can show a reliable method for converting an IPv6 IP to a decimal value using MySQL, that would be awesome!

There is another method though: use DECIMAL and store the entire IP as an integer. IPv6 IPs can range from 0 to 340282366920938463463374607431768211455 when expressed as an integer. You can store that in a DECIMAL(39) column. Mask lookups will still involve using 128 lookups (or 8 if you want to limit yourself). However, the advantage of DECIMAL(39) is that you can do range lookups.