Systems and methods for applying transformations to IP addresses obtained by domain name service (DNS)
Described herein are systems and methods for improving networked communication systems by transforming IP addresses. In particular, an intermediary device disposed in a network between a plurality of clients and a plurality of servers can receive a request for a service offered at a specified domain name. The appliance can also receive a DNS-resolved primary address for a server associated with the domain name, and transform the primary address to a secondary address for the server. The address transformation can be done by the intermediary to prevent service interruption between a client and server due, for example, to server maintenance.
1. A method for transforming server internet protocol addresses specified via a domain name, the method comprising:
(a) receiving, by an intermediary device between a plurality of a clients and a plurality of servers, a request to access a server identified by a domain name;
(b) receiving, by the intermediary device, an internet protocol (IP) address for the domain name of the server resolved by a domain name service;
(c) identifying, by the intermediary device, a transformation policy for the server, the transformation policy comprising a translation IP address and a translation mask;
(d) transforming, by the intermediary device, the IP address of the server to a transformed IP address for the server by applying a second bitwise operation of the translation IP address of the transformation policy to a result of a first bitwise operation of the translation mask of the transformation policy to the IP address; and
(e) forwarding, by the intermediary device, the request to the transformed IP address.
2. The method of claim 1 , wherein step (b) further comprises receiving the internet protocol address of the server from the domain name service.
3. The method of claim 1 , wherein step (c) further comprises identifying, by the intermediary device, via the transformation policy the translation IP address comprising a fixed IP address replacement of the IP address.
4. The method of claim 1 , wherein step (c) further comprises identifying, by the intermediary device, via the transformation policy the translation mask comprising a predetermined number of bits of the IP address to replace with a value specified by the translation IP address.
5. The method of claim 1 , wherein step (d) further comprise transforming the IP address by applying a bitwise AND operation of the IP address with the translation mask.
6. The method of claim 5 , further comprising applying the result of the bitwise AND operation to a bitwise OR operation of the translation IP address and the translation mask.
7. The method of claim 5 , further comprising determining a bitwise ones complement of the translation mask prior to the applying the bitwise AND operation.
8. The method of claim 1 , further comprising the transformation policy specifying the translation IP address and the translation mask to transform the IP address to a secondary IP address of the server.
9. The method of claim 8 , wherein step (e) further comprises forwarding the request to the transformed IP address identifying the secondary IP address of the server.
10. The method of claim 1 , wherein step (c) further comprises the transformation policy specifying the domain name for the translation IP address and the translation mask.
11. A system for transforming server internet protocol addresses specified via a domain name, the system comprising:
an intermediary device between a plurality of a clients and a plurality of servers, receive a request to access a server identified by a domain name and receiving, an internet protocol (IP) address for the domain name of the server resolved by a domain name service;
a transformation policy for the domain name, the transformation policy comprising a translation IP address and a translation mask; and
an IP address transformer of the intermediary device transforming the IP address of the server to a transformed IP address for the server by applying a second bitwise operation of the translation IP address of the transformation policy and to a result of a first bitwise operation of the translation mask of the transformation policy to the IP address;
wherein the intermediary device forwards the request to the transformed IP address.
12. The system of claim 11 , wherein the intermediary device receives the internet protocol address of the server from the domain name service.
13. The system of claim 11 , wherein the transformation policy identifies the translation IP address comprising a fixed IP address replacement of the IP address.
14. The system of claim 11 , wherein the transformation policy identifies the translation mask comprising a predetermined number of bits of the IP address to replace with a value specified by the translation IP address.
15. The system of claim 11 , wherein the IP address transformer transforms the IP address by applying a bitwise AND operation of the IP address with the translation mask.
16. The system of claim 15 , wherein the IP address transformer applies the result of the bitwise AND operation to a bitwise OR operation of the translation IP address and the translation mask.
17. The system of claim 15 , wherein the IP address transformer determines a bitwise ones complement of the translation mask prior to the applying the bitwise AND operation.
18. The system of claim 11 , wherein the transformation policy specifies the translation IP address and the translation mask to transform the IP address to a secondary IP address of the server.
19. The system of claim 18 , wherein the intermediary device forwards the request to the transformed IP address identifying the secondary IP address of the server.
20. A method for transforming server internet protocol addresses specified via a domain name, the method comprising:
(a) receiving, by an intermediary device between a plurality of a clients and a plurality of servers, a request to access a server identified by a domain name;
(b) receiving, by the intermediary device, an internet protocol (IP) address for the domain name of the server resolved by a domain name service;
(c) identifying, by the intermediary device, a transformation policy for the server, the transformation policy comprising a translation IP address and a translation mask;
(d) transforming, by the intermediary device, the IP address of the server to a transformed IP address for the server by applying a bitwise AND operation of the translation IP address to a result of a bitwise OR operation of the translation mask and the IP address; and
(e) forwarding, by the intermediary device, the request to the transformed IP address.