FAILURE SYSTEM FOR DOMAIN NAME SYSTEM CLIENT

• US 20120072569A1
• Filed: 11/29/2011
• Published: 03/22/2012
• Est. Priority Date: 02/12/2010
• Status: Active Grant

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Inventors: Xu, Ce
• Granted Patent: US 8,799,718 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• 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 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

A method performed by a domain name service client includes storing DNS entries in a local cache; sending a DNS query to another device to obtain an update to one of the DNS entries; determining whether a DNS response is received; and resetting a time-to-live (TTL) timer associated with the one of the DNS entries when the DNS response is not received.

Claims

1. A method comprising:

storing, by a domain name system (DNS) device, DNS entries in a local cache;

sending, by the DNS device, a DNS query to another device to obtain an update to one of the DNS entries;

determining, by the DNS device, whether a DNS response for the DNS query is received;

reading, by the DNS device, a response code value included in the DNS response in response to determining that the DNS response is received; and

selecting, by the DNS device, an error category corresponding to the response code value based on the reading.

2. The method of claim 1, wherein if the DNS response is received, the method further comprises:

determining whether a DNS resource record (RR) included in the DNS response is empty or not; and

wherein the reading comprises;

reading the response code value from the DNS response in response to determining that the DNS RR is empty.

3. The method of claim 1, wherein if the DNS response is not received, the method further comprises:

continuing to store the one of the DNS entries; and

resetting a time-to-live timer associated with the one of the DNS entries.

4. The method of claim 1, further comprising:

continuing to store the one of the DNS entries based on the selected error category; and

resetting a time-to-live timer associated with the one of the DNS entries based on the selected error category.

5. The method of claim 1, further comprising:

deleting the one of the DNS entries based on the selected error category; and

deleting a time-to-live timer associated with the one of the DNS entries based on the selected error category.

6. The method of claim 1, wherein if the DNS response is received, the method further comprises:

determining whether a DNS resource record (RR) included in the DNS response is empty or not;

updating the one of the DNS entries in response to determining that the DNS RR is not empty; and

resetting a time-to-live timer associated with the one of the DNS entries.

7. The method of claim 1, wherein the error category corresponds to two or more response code values, and the response code value is one of the two or more response code values.

8. The method of claim 1, wherein the error category represents one of a temporary condition or a permanent condition.

9. A device comprising:

a domain name system (DNS) client;

one or more memories to store instructions; and

one or more processors to execute the instructions in the one or more memories to;

store DNS entries;

send a DNS query to another device to obtain an update to one of the DNS entries;

determine whether a DNS response to the DNS query is received;

read a response code value included in the DNS response in response to a determination that the DNS response is received; and

select an error category corresponding to the response code value.

10. The device of claim 9, wherein if a determination is that the DNS response is not received, the one or more processors are to execute instructions to:

continue to store the one of the DNS entries; and

reset a time-to-live timer associated with the one of the DNS entries.

11. The device of claim 9, wherein if the determination is that the DNS response is received, the one or more processors are to execute instructions to:

determine whether a DNS resource record (RR) included in the DNS response is empty or not; and

read the response code value from the DNS response in response to a determination that the DNS RR is empty.

12. The device of claim 9, wherein the one or more processors are to execute instructions to:

continue to store the one of the DNS entries based on the selected error category; and

reset a time-to-live timer associated with the one of the DNS entries based on the selected error category.

13. The device of claim 9, wherein if the determination is that the DNS response is received, the one or more processors are to execute instructions to:

determine whether a DNS resource record (RR) included in the DNS response is empty or not;

update the one of the DNS entries in response to a determination that the DNS RR is not empty; and

reset a time-to-live timer associated with the one of the DNS entries.

14. The device of claim 9, wherein the one or more processors are to execute instructions to:

delete the one of the DNS entries based on the selected error category; and

delete a time-to-live timer associated with the one of the DNS entries based on the selected error category.

15. The device of claim 9, wherein the error category corresponds to two or more response code values, and the response code value is one of the two or more response code values.

16. The device of claim 9, wherein the error category corresponds to errors pertaining to a DNS server.

17. A non-transitory storage medium storing instructions executable by at least one computational device to:

manage domain name system (DNS) entries in a cache associated with a DNS client;

send a DNS query to another device to obtain an update to one of the DNS entries;

read a response code value included in a DNS response; and

select an error category corresponding to the response code value.

18. The non-transitory storage medium of claim 17, further comprising one or more instructions to:

continue to store the one of the DNS entries based on the selected error category; and

reset a time-to-live timer associated with the one of the DNS entries based on the selected error category.

19. The non-transitory storage medium of claim 17, further comprising one or more instructions to:

determine whether a DNS resource record (RR) included in the DNS response is empty or not;

update the one of the DNS entries in response to a determination that the DNS RR is not empty; and

reset a time-to-live timer associated with the one of the DNS entries.

20. The non-transitory storage medium of claim 17, wherein the error category corresponds to two or more response code values, and the response code value is one of the two or more response code values.