Stateful IPv4-IPv6 DNS application level gateway for handling topologies with coexisting IPv4-only, Ipv6-only and dual-stack devices
US7526562B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 2003 |
| Grant date | Apr 28, 2009 |
| Priority date | — |
| Expiry date | Mar 23, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2101/659
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Disclosed are methods and apparatus for efficiently and reliably handling DNS (domain name service) queries and responses. In general terms, mechanisms are provided for forwarding only one DNS response to a DNS client when two DNS responses having different protocols (IPv4 or IPv6) may be received, e.g., within a DNS handling device for a particular DNS query. The DNS handling device determines whether to forward or hold a first received DNS response based on a number of criteria. The DNS handling device also determines whether to forward a first or second received response to the DNS client when a first and second response for a particular query is received. In certain cases, a first received DNS response for a particular DNS query may be held until a second better response is received or a timer expires.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.