Branch office DNS storage and resolution

• US 20070041393A1
• Filed: 08/19/2005
• Published: 02/22/2007
• Est. Priority Date: 08/19/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Westhead, Jeffrey, Muggli, Nathan, Esibov, Levon
• Granted Patent: US 7,567,582 B2
• Time in Patent Office: Days
• US Class Current: 370/428
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 61/58 Caching of addresses or names
• CPC Class Codes: H04L 61/59 using proxies for addressing

Abstract

Maintaining DNS records. A computing network system includes a local Domain Name Service (DNS) server connected to one or more local clients or resources at a local branch office in an enterprise network. The local DNS server advertises to the local clients or resources at the local branch office that the DNS server is authoritative. The DNS server receives record information for the local clients or resources. An attempt is made to forward the record information to an enterprise hub DNS server. The record information is stored persistently in a cache. Storing the record information persistently in cache may be performed selectively or non-selectively. When performed selectively, the record information is stored or not stored depending on some result or other action. For example, the result may be stored or not stored depending on the results of attempting to forward to an enterprise hub DNS server.

Claims

1. In a computing network system that includes a local Domain Name Service (DNS) server connected to one or more local clients or resources at a local branch office in an enterprise network, a method of maintaining records for the one or more local clients or resources at the local DNS server, the method comprising:

an act of advertising to the one or more local clients or resources at the local branch office that the DNS server is authoritative;

an act of receiving record information for the one or more local clients or resources;

an act of attempting to forward the record information to an enterprise hub DNS server; and

an act of storing the record information persistently in a cache, wherein storing the record information persistently in cache may be performed selectively or non-selectively.

2. The method of claim 1, wherein the act of storing the record information persistently in a cache is selectively performed based on a response received as a result of the act of attempting to forward the record information to an enterprise hub DNS server 108 the method further comprising:

an act of receiving 310 a response in response to the act of attempting 306 to forward the record information to an enterprise hub DNS server.

3. The method of claim 2, wherein the response is a failure response from a communication stack indicating that a connection between the local branch office and the enterprise hub is non-operational, wherein the act of storing the record information persistently in the cache is selectively performed such that the record information is stored in the cache, the method further comprising:

an act of flagging the record information with a maximum lifetime after which the record information expires.

4. The method of claim 2, wherein the response is a succeed response from the enterprise hub indicating that the record information has been used to update a record for a client or resource, wherein the act of storing the record information persistently in the cache is selectively performed such that the record information is stored in the cache.

5. The method of claim 2, wherein the response is a failure response from the enterprise hub indicating that the record information may not be used to update a record for a client or resource, wherein the act of storing the record information persistently in the cache is selectively performed such that the record information is not stored in the cache, the method further comprising:

an act of sending a failure response to a local client or resource that sent the record information received in the act of receiving record information for the one or more local clients or resources.

6. The method of claim 1, wherein the act of storing the record information persistently in a cache is non-selectively performed, the method further comprising:

an act of receiving a response in response to the act of attempting to forward the record information to an enterprise hub DNS server.

7. The method of claim 6, wherein the response is a failure response from the enterprise hub indicating that the record information may not be used to update a record for a client or resource, the method further comprising:

an act of invalidating the record information stored persistently in the cache; and

an act of sending a failure response to a local client or resource that sent the record information received in the act of receiving record information for the one or more local clients or resources.

8. The method of claim 6, wherein the response is a failure response from a communication stack indicating that a connection between the local branch office and the enterprise hub is non-operational, the method further comprising:

an act of flagging the record information with a maximum lifetime after which the record information expires.

9. The method of claim 1, wherein the record information includes an IP address.

10. The method of claim 1, wherein the local DNS server and the enterprise hub are in a common domain namespace.

11. The method of claim 1, further comprising the act of caching remote DNS records for remote names when a connection between the local branch office and the enterprise hub is operational.

12. A computer program product comprising one or more computer-readable media having thereon computer-executable instructions that, when executed by one or more processors of a computing system, cause the computing system to perform the method recited in claim 1.

13. A system for storing record information for clients or resources in a local branch office of an enterprise network, the system comprising:

a branch office, wherein the branch office comprises;

a branch Domain Name Service (DNS) server, the branch DNS server comprising a persistent cache of record information for clients or resources associated with the branch office;

enterprise network hardware coupled to the branch DNS server and configured to couple to a network to connect the branch office to an enterprise hub;

local network hardware configured to couple to the clients or resources associated with the branch office; and

computer executable instructions disposed in the branch DNS server that allows the branch DNS server to advertise through the local network hardware to the clients or resources associated with the branch office that the branch DNS server is authoritative and to attempt to forward record update data to the enterprise hub.

14. The system of claim 13, further comprising one or more local clients or resources coupled to the local network hardware.

15. The system of claim 14, wherein the one or more local clients or resources comprise a file server.

16. The system of claim 14, wherein the one or more local clients or resources comprise a print server.

17. The system of claim 14, wherein the one or more local clients or resources comprise a shared store on a client computer.

18. The system of claim 13, wherein the enterprise network hardware is coupled to a communication stack that is configured to generate a failure message when attempts to forward record information to the enterprise hub cannot be completed because a link between the branch office and the enterprise hub is non-operational.

19. In a computing network system that includes a local Domain Name Service (DNS) server connected to one or more local clients or resources at a local branch office in an enterprise network, a method of resolving host names, the method comprising:

an act of receiving a request from one of the local clients or resources that includes a query including a host name;

an act of checking a local persistent cache to determine if a local record exists to resolve an IP address for the host name and if the local record exists to resolve an IP address for the host name at the local persistent cache, an act of sending the IP address to the one of the local clients or resources, wherein the local persistent cache includes local records for at least a portion of the one or more local clients or resources;

if a local record does not exist in the local persistent cache to resolve an IP address for the host name, an act of checking a local temporary cache to determine if a record exists to resolve the IP address for the host name and if the record exists to resolve the IP address for the host name at the local temporary cache, an act of sending the IP address to the one of the local clients or resources, wherein the local temporary cache includes records for clients or resources outside of the local branch office; and

if a local record does not exist in the local persistent cache or the local temporary cache to resolve the IP address for the host name, an act of attempting to query an enterprise hub to resolve the IP address.

20. The method of claim 19, further comprising:

an act of receiving record information including the IP address in response to attempting to query an enterprise hub to resolve the IP address;

an act of storing the record information in the local temporary cache; and

an act of sending the IP address to the one of the local clients.