Can wildcard queries be used with the DBL?
Can wildcard queries be used with the DBL?
The DBL supports wildcard lookups. Querying the full hostname will return a positive result if the host’s domain is listed. In other words, DBL lists at the main domain level, and all hostnames and subdomains of that domain also return a “listed” result. Therefore, it is optional and not necessary to strip the hostname down to query the actual domain only.
For example, if example.tld is listed:
$ host example.tld.dbl.spamhaus.org
example.tld.dbl.spamhaus.org has address 127.0.1.2
Any wildcard: “*.example.tld” sub-domain will also get the same response:
$ host www.bank.phish.tld.dbl.spamhaus.org
www.bank.phish.tld.dbl.spamhaus.org has address 127.0.1.2
The wildcard query works for subdomains only, and not variations of the domain itself:
$ host example.tld.dbl.spamhaus.org
example.tld.dbl.spamhaus.org not found: 3(NXDOMAIN)
This enables the DBL to be used for either URI type queries (domains in links advertised in spam) and RHSBL type queries such as rDNS, HELO string, FROM and other email headers.
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