Cisco Technology, Inc.

Opendns, Inc.

David Ulevitch

Noah Treuhaft

Michael Damm

Matthew Dempsky

Lucas Siba

Geoff Townsend

Yariv Keinan

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

A client analyzes requests for network resources to determine an IP address associated with the request, such as a destination IP address of a network packet. The client device selectively routes the request and other traffic associated with the IP address. The client device establishes a tunnel or other direct connection with a remote server. Network traffic can be selectively routed to the destination IP address associated with a resource request, or to the remote server based on the destination IP address associated with the request. The system can route client network requests to the remote server based on a category or other information associated with the destination IP address. Network packets associated with malicious or suspicious IP addresses, for example, may be routed to the remote server for performance of security features, while packets associated with other IP addresses may be directly routed to their target destination.

Selective routing of network traffic for remote inspection in computer networks

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

A recursive DNS server receives a request for domain name information associated with a domain name from a subscriber. In response to the request for domain name information, the recursive DNS nameserver determines a subscriber identifier and subscriber information associated with the subscriber identifier. The recursive DNS nameserver resolves the request for domain name information based on the subscriber information to generate a response to the request for domain name information. The recursive DNS nameserver then returns the response to the request for domain name information to the subscriber.

Growing community of inventors

San Francisco, CA, United States of America

David Ulevitch