Domain name system CNAME record management
A DNS name server manages CNAME records. The server receives a query for a first Address record for a fully qualified domain name from a requester. The server determines that the fully qualified domain name has a CNAME record, where the fully qualified domain name is a root domain. The server traverses a chain according to the CNAME record to locate a second Address record that includes an IP address. The server generates a response to the query that includes a third Address record for the fully qualified domain name that includes at least the IP address of the located second Address record. The server transmits the generated response to the requester.
1. A method in a Domain Name System (DNS) name server for managing Canonical Name (CNAME) records, comprising:
receiving a query for a first Address record for a fully qualified domain name from a requester;
determining that the fully qualified domain name has a CNAME record, wherein the fully qualified domain name is a root domain;
traversing a CNAME chain according to the CNAME record to locate a second Address record at the end of the CNAME chain that includes an IP address;
generating a third Address record for the fully qualified domain name, the third Address record including at least the IP address of the located second Address record at the end of the CNAME chain;
generating a response to the query for the first Address record for the fully qualified domain name that includes the generated third Address record for the fully qualified domain name instead of the CNAME record; and
transmitting the generated response to the requester.
2. The method of claim 1 , wherein the generated response further includes a first Time to Live (TTL) value that is equivalent to a second TTL value of the located second Address record.
3. The method of claim 1 , wherein the generated response further includes a Time to Live (TTL) value that is equivalent to a longest TTL value in the CNAME chain.
4. The method of claim 1 , wherein the generated response further includes a Time to Live (TTL) value that is smaller than each other TTL value in the CNAME chain.
5. The method of claim 1 , further comprising, caching the generated response.
6. The method of claim 1 , wherein the DNS name server is an authoritative name server for the fully qualified domain name.
7. The method of claim 1 , wherein receiving the query for the first Address record for the fully qualified domain name from the requester comprises:
receiving the query from the requester, wherein the query is received from a different DNS name server.
8. An apparatus, comprising:
a Domain Name System (DNS) name server including a set of one or more processors and a set of one or more non-transitory computer-readable storage mediums storing instructions that, when executed by the set of processors, cause the set of processors to perform the following operations:
receive a query for a first Address record for a fully qualified domain name from a requester;
determine that the fully qualified domain name has a Canonical Name (CNAME) record, wherein the fully qualified domain name is a root domain;
traverse a CNAME chain according to the CNAME record to locate a second Address record at the end of the CNAME chain that includes an IP address;
generate a third Address record for the fully qualified domain name, the third Address record including at least the IP address of the located second Address record at the end of the CNAME chain;
generate a response to the query for the first Address record for the fully qualified domain name that includes the generated third Address record for the fully qualified domain name instead of the CNAME record; and
transmit the generated response to the requester.
9. The apparatus of claim 8 , wherein the generated response is further to include a first Time to Live (TTL) value that is equivalent to a second TTL value of the located second Address record.
10. The apparatus of claim 8 , wherein the generated response is further to include a Time to Live (TTL) value that is equivalent to a longest TTL value in the CNAME chain.
11. The apparatus of claim 8 , wherein the generated response is further to include a Time to Live (TTL) value that is smaller than each other TTL value in the CNAME chain.
12. The apparatus of claim 8 , wherein the set of one or more non-transitory computer-readable storage mediums further stores instructions that, when executed by the set of processors, cause the set of processors to cache the generated response.
13. The apparatus of claim 8 , wherein the DNS name server is an authoritative name server for the fully qualified domain name.
14. The apparatus of claim 8 , wherein receiving the query for the first Address record for the fully qualified domain name from the requester comprises:
receiving the query from the requester, wherein the query is received from a different DNS name server.
15. A non-transitory machine-readable storage medium that provides instructions that, when executed by a processor of a Domain Name System (DNS) name server, cause the processor to perform operations comprising:
receiving a query for a first Address record for a fully qualified domain name from a requester;
determining that the fully qualified domain name has a Canonical Name (CNAME) record, wherein the fully qualified domain name is a root domain;
traversing a CNAME chain according to the CNAME record to locate a second Address record at the end of the CNAME chain that includes an IP address;
generating a third Address record for the fully qualified domain name, the third Address record including at least the IP address of the located second Address record at the end of the CNAME chain;
generating a response to the query for the first Address record for the fully qualified domain name that includes the generated third Address record for the fully qualified domain name instead of the CNAME record; and
transmitting the generated response to the requester.
16. The non-transitory machine-readable storage medium of claim 15 , wherein the generated response further is to include a first Time to Live (TTL) value that is equivalent to a second TTL value of the located second Address record.
17. The non-transitory machine-readable storage medium of claim 15 , wherein the generated response further is to include a Time to Live (TTL) value that is equivalent to a longest TTL value in the CNAME chain.
18. The non-transitory machine-readable storage medium of claim 15 , wherein the generated response further is to include a Time to Live (TTL) value that is smaller than each other TTL value in the CNAME chain.
19. The non-transitory machine-readable storage medium of claim 15 , further storing instructions that, when executed by the processor, cause the processor to perform the following operation:
caching the generated response.
20. The non-transitory machine-readable storage medium of claim 15 , wherein the DNS name server is an authoritative name server for the fully qualified domain name.
21. The non-transitory machine-readable storage medium of claim 15 , wherein receiving the query for the first Address record for the fully qualified domain name from the requester comprises:
receiving the query from the requester, wherein the query is received from a different DNS name server.