Manual:$wgBlockCIDRLimit

Access: $wgBlockCIDRLimit
Maximum CIDR range when blocking an IP range.
Introduced in version:	1.16.0 (r58377)
Removed in version:	Still in use
Allowed values:	(positive integer)
Default value:	(see below)
Other settings: Alphabetical | By function

Details

Maximum CIDR range when blocking an IP range.

Default values

MediaWiki version:

≥ 1.20

MediaWiki 1.20wmf4 and later: (See gerrit:11259 and gerrit:11260)

$wgBlockCIDRLimit = [
	'IPv4' => 16, # Blocks larger than a /16 (64k addresses) will not be allowed
	'IPv6' => 19,
];

MediaWiki versions:

1.16 – 1.19

Before MediaWiki 1.20wmf4:

$wgBlockCIDRLimit = array(
       'IPv4' => 16, # Blocks larger than a /16 (64k addresses) will not be allowed
       'IPv6' => 64, # 2^64 = ~1.8x10^19 addresses
);

This setting does not control Extension:GlobalBlocking , which has its own configuration setting.