Back in August of 2009, we announced the national rollout of the Comcast Domain Helper service, which was designed to help customers by providing suggestions and links when they mistyped a web address. With the full deployment of DNSSEC in our network now complete, Domain Helper has been turned off.
When we launched the Domain Helper service, we also set in motion its eventual shutdown due to our plans to launch DNSSEC. Domain Helper has been turned off since DNS response modification tactics, including DNS redirect services, are technically incompatible with DNSSEC and/or create conditions that can be indistinguishable from malicious modifications of DNS traffic (including DNS cache poisoning attacks). Since we want to ensure our customers have the most secure Internet experience, and that if they detect any DNSSEC breakage or error messages that they know to be concerned (rather than not knowing if the breakage/error was "official" and caused by our redirect service or "unofficial" and caused by an attacker), our priority has been placed on DNSSEC deployment — now automatically protecting our customers as part of Constant Guard™ from Xfinity.
If you are interested to know more about the work we have done with DNSSEC, please take a look at our DNSSEC Information Center as well as our Constant Guard™ page.
For information about our DNSSEC deployment, click here.