Translations:Manual:Combating spam/120/en

The DNS blacklist operates as follows:
 * A wiki gets an edit or new-user registration request from some random IP address (for example, in the format '123.45.67.89')
 * The four IP address bytes are placed into reverse order, then followed by the name of the desired DNS blacklist server
 * The resulting address is requested from the domain name server (in this example, '89.67.45.123.zen.spamhaus.org.' and '89.67.45.123.dnsbl.tornevall.org.')
 * The server returns not found (NXDOMAIN) if the address is not on the blacklist. If is on either blacklist, the edit is blocked.