DNS blacklist

From Secure Web Gateway


Set the DNSBL reference service to prevent users from visiting dangerous websites.

Before establishing connection with "www.example.com", SafeSquid performs a DNS lookup for "example.com.in.dnsbl.org".

SafeSquid caches the DNS query results for efficiency

Access The SafeSquid User Interface


Go to Configure Page

Goto configure.png

Go to Real time content security

Go to real time content security.png

Go to DNS Blacklist Section

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Enable or Disable the use of DNSBL service.

Disable this section if you do not want to query DNS blacklist services

  • TRUE : Enable DNS blacklist section.
  • FALSE : Disable DNS blacklist section.


Name of the template to send when domain is found to be blocked.

Leave this blank, to use default Template "blocked".


This field needs to be filled in, only for making query to blacklist services like DNSBL.

The website to query is appended with DNSBL's domain name.

For example : If you set DNSBL's domain name as "in.dnsbl.org", then before establishing connection with "example.com", SafeSquid performs a DNS lookup for "example.com.in.dnsbl.org".

NOTE : You can also use any other service that provides similar DNS blacklist service.

Blocked IP addresses

Enter the comma separated list of IP address ranges that can be returned by DNS blacklist queries after matching which cause the page to be blocked.

For example : If You set domain name as "in.dnsbl.org" then it returns an IP in the range to for malafide servers.

Returned IP Convention for domain "in.dnsbl.org" are:

""=>"UCE", ""=>"Fraud", ""=>"Spam Promo", ""=>"Illegal Content",

""=>"Pre-emptive", ""=>"Improper List Practices" ""=>"Botnet Activity / Malware".




I want to block websites using my DNS blacklisting server.

I want to use blacklisting domain as in.dnsbl.org

Blocked IP address is to be set

For all the matching entries block the domain.

Blocked domain will display SafeSquid’s blocked_bypass template.

DNS Blacklisting is used in a situation where Blocking of websites are done by SOC provided list of websites.

DNS Blacklisting should also be considered in a situation where there are large number of domains to be blocked.

Once the DNSB blacklisting is configured, SafeSquid it will look for the entry of URL and the dnsbl domain you have configured. Example: SafeSquid will check for the DNS record of google.com.in.dnsblbl.org in the db.in.dnsbl.org file, If found then the URL will be blocked else the page will be loaded.