Cisco Technology, Inc.

Opendns, Inc.

Michael Damm

Noah Treuhaft

David Ulevitch

Matthew Dempsky

Doug Tabacco

Douglas Tabacco

Mathew Dempsky

A recursive DNS nameserver system and related domain name resolution techniques are disclosed. The DNS nameservers utilize a local cache having previously retrieved domain name resolution to avoid recursive resolution processes and the attendant DNS requests. If a matching record is found with a valid (not expired) TTL field, the nameserver returns the cached domain name information to the client. If the TTL for the record in the cache has expired and the nameserver is unable to resolve the domain name information using DNS requests to authoritative servers, the recursive DNS nameserver returns to the cache and accesses the resource record having an expired TTL. The nameserver generates a DNS response to the client device that includes the domain name information from the cached resource record. In various embodiments, subscriber information is utilized to resolve the requested domain name information in accordance with user-defined preferences.

Robust domain name resolution

Systems and methods for processing domain name system requests in accordance with subscriber information are provided. A request for domain name information can be correlated with subscriber information using a subscriber identifier to resolve the domain name information at a domain name system (DNS) nameserver. The subscriber identifier and/or subscriber information may be transmitted from a DNS nameserver to a webserver using the domain name information provided in response to the subscriber's DNS queries. The subscriber identifier and/or information may be used in delivering a landing page or in facilitating proxying of resource requests for the requested domain.

Cross-protocol communication in domain name systems

Systems and methods for processing requests for domain name information in accordance with subscriber information are provided. A request for domain name information can be correlated with subscriber preferences to resolve the domain name information. Domain names may be flagged for blocking or proxying by one or more subscriber preferences. In response to a flagged domain name, a client device can be redirected to a web server that can function as proxy on behalf of the user for accessing the flagged domain. In one example, user preferences and/or network preferences can be used to determine whether a particular user can bypass a blocking preference and access the flagged domain using the proxy.

Selective proxying in domain name systems

Growing community of inventors

San Francisco, CA, United States of America

Michael Damm