How To Check DNS Blacklist Entries

Posted by: admin  :  Category: Bits and Bytes

In case you ever happen to be listed on a DNS blacklist you’ll propably find it useful checking for the actual DNS reply.
The point is that many popular blacklists usually provide information and database checks on their websites, however the latter one very often do not reflect current entries withint the blacklist.

So, the way to go is either using ‘host’, ‘dig’ or ‘nslookup’. Requested addresses must be specified equally as if you were actually searching for a reverse entry (PTR).

In the example given, the IP address “” (reversed is assumed, while ‘ns.of.choice’ is a synonym for your local nameserver.

So a query for ‘dig’ might look like this (output stripped a little):

#dig @ns.of.choice ANY

;; ANSWER SECTION: 3600 IN A 3600 IN TXT “sample for typical rbl message”

The same query for the ‘host’ command:

#host -t any ns.of.choice
Using domain server:
Name: ns.of.choice
Aliases: has address descriptive text “sample for a typical rbl message”
And the same again using ‘nslookup’:

#nslookup -class=any ns.of.choice
Server: ns.of.choice

Address: text = “sample for typical rbl message”

You may also choose to query any authoritative nameserver of the blacklist in particular (refer to authority section or the SOA records respectively), since querying your local name-server may be not be accurate due to TTL intervals.

CompleteWhois also provides a conventient interface for searching multiple RBL’s at once.

4 Responses to “How To Check DNS Blacklist Entries”

  1. Flexsin Says:


    How can i check a domain or website URL is black listed or not, if the website hosted on a shared server.


  2. neddy Says:

    This is a little off track, but i was reading through your tutorial, and thought that i might mention that i use to run blacklist checks on my domains, by just entering in the domain name, and letting it return the blacklist codes on a good 100 or so known blacklists…
    is the page, in case anyone else is interested.

    — Neddy.

  3. Sherry Says:

    Interesting tutorial just over my head! I tried the URL that Neddy suggested and it worked for me. Thanks to both of you.

  4. Adrian Says:

    Check this one