Abusive ISPs

These are Internet Service Providers that have been found to tamper with your DNS (or OpenNIC related) traffic, do note that this list is only for previously mentioned abuse, nothing else.

Some abusive ISPs will intercept DNS traffic on port 53 and return results from their own servers instead. This makes access to alternative TLDs difficult, and is a privacy concern as it allows the ISPs to carry out more detailed logging of the domains you resolve.

Some OpenNIC DNS servers also listen on an alternative port (generally 5353) which is less likely to be tampered with by ISPs.

To test if an ISP is tampering with DNS traffic, you can use the dig command from the dnsutils package. Select a server from the Tier 2 page which supports an alternative port. In my example I have used First, try querying for the root zone (.) on the default port:

dig SOA . @
.	58346	IN	SOA	a.root-servers.net. nstld.verisign-grs.com. 2015080300 1800 900 604800 86400

You can see from the returned SOA above that the DNS request has been hijacked by the ISP as a.root-servers.net is not an OpenNIC DNS server. If the SOA you get looks more like the one below, then your ISP is probably not hijacking your DNS requests.

Now try again on the alternative port:

dig SOA . @ -p 5353
.	86319	IN	SOA	ns0.opennic.glue. hostmaster.opennic.glue. 2015080301 1800 900 604800 3600

You can see that the SOA returned is OpenNIC's, meaning no hijacking has taken place on the alternative port. If this result differs from the previous result or the first result times out with connection timed out; no servers could be reached, then your ISP is likely to be hijacking DNS.

Please refer to the answer of this question to use iptables to reroute your DNS traffic to an alternative port on an OpenNIC server. Remember to change the server's IP address.

You could also contact your ISP to complain about their use of DNS hijacking.

This list is very incomplete. If you are certain that your ISP is hijacking DNS or is involved in other questionable practices, please add it below.

Country ISP Earliest report Last seen Source DPI Level Notes
Taiwan HiNet 2019-01-16 fusl no blocking of selective domains Returns NXDOMAIN for some very specific domains, hijacking common public DNS resolvers like Google, OpenDNS and CloudFlare, Quad9 seems to be unaffected
Austria 3 / drei.at 2018-01-28 fusl no NXDOMAIN search engine redir NXDOMAIN redirect to, proof
- Vultr/Choopa 2017-11-03 fusl yes blocking of selective domains DPI on UDP/53, blocks any DNS request containing the text minexmr.com. in the query name (proof)
United States CenturyLink 2017-08-28 some user on #opennic no NXDOMAIN search engine redir Reproduced by fusl - NXDOOMAIN redirect to redirecting to http://webhelper.centurylink.com/index.php?origURL=<domain>&r=&bc=
United States Cox 2017-08-16 - yes NXDOMAIN search engine redir Enhanced Error Results Service; albeit the official page states that opt-outs are possible, multiple reports show that users are struggling doing so: DNS Hijacking (A.K.A 'Enhanced Error Results'), Cox Hijacking DNS again
Peru Bitel 2017-06-23 Tedel on #opennic ? ? IRC conversation log
United States AT&T 2017-03-27 news no NXDOMAIN search engine redir ETM Details with Opt-Out Option (screenshot), ATT DNS Assist Page - AT&T; Community (screenshot)
- Level3 2015-11-13 2019-06-09 gorbilax on reddit no NXDOMAIN search engine redir Level3 DNS servers redirecting to search page : networking, NXDOMAIN redirect to and on their well-known servers, proof
United States T-Mobile US 2015-07-20 thefinn93 on reddit no NXDOMAIN search engine redir How do I turn of NXDOMAIN hijacking?
Indonesia Telkom 2015-04-27 blog post ? ? Bagaimana internet positif Telkom bekerja?
United States Sprint 2014-09-05 sanityvampire on reddit no NXDOMAIN search engine redir Are Sprint 3G and 4G towers hijacking NXDOMAIN responses? More information in comments...
United States CenturyLink 2011-12-21 DSLReports Forums user no NXDOMAIN search engine redir Re: [Qwest] Opting out of CenturyLink Web Helper hijacking not working
Spain ONO 2010-05-10 blog post no NXDOMAIN search engine redir Allowed cross-site-scripting attacks, iniqua » Archive » XSS Reflected dnssearch.Ono.es NXD redirect
Australia Telstra 2009-11-20 news, CRN Australia no NXDOMAIN search engine redir BigPond redirects typos to 'unethical' branded search page
United States RCN 2009-10-13 blog post no NXDOMAIN search engine redir InfiniteEdge: Who Stole My Web Browser?
United States Mediacom 2009-09-25 YourName on reddit no redirection of selective domains Redirects search.live.com to own search engine, Want a real world example of why we need network neutrality? I have one here.
Canada Bell Internet 2009-08-04 timothy on Slashdot no NXDOMAIN search engine redir Bell Starts Hijacking NX Domain Queries
United States Comcast 2009-07-28 2012-01-01 news no NXDOMAIN search engine redir Comcast trials Domain Helper service DNS hijacker, disabled 2012; Comcast Domain Helper Shuts Down
Germany T-Online 2009-04-09 - no NXDOMAIN search engine redir Neues Leistungsmerkmal 'Navigationshilfe'
United States Optimum Online 2008-09-25 - no NXDOMAIN search engine redir Optimum Online - DNS Assistance
Canada Rogers 2008-07-20 news no ad content injection Rogers Uses Deep Packet Inspection for DNS Redirection - Is hijacking websites for advertising a violation of net neutrality?
Australia Telstra 2008-03-15 blog post no dns redirection Road Runner DNS hijack causing slow web pages
United States Verizon 2007-06-21 - no NXDOMAIN search engine redir Opt Out of DNS Assistance
United Kingdom TalkTalk FIXME - no NXDOMAIN search engine redir TalkTalk Error Replacement Service
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  • Last modified: 5 years ago
  • by fusl