Inter-pod traffic redirection and handling in a multi-pod network environment

• US 9,967,231 B2
• Filed: 03/18/2015
• Issued: 05/08/2018
• Est. Priority Date: 03/18/2015
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Shetty, Nikhil Gopinath, Gaggara, Siva, Rathi, Ravindra Nandalal, Song, Jialin
• Primary Examiner(s): Kang, Suk Jin
• Application Number:
  US14/662,006
• Publication Number:
  US 20160277355A1
• Time in Patent Office: 1,147 Days
• Field of Search: None
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 45/72 Routing based on the source address
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2592 using tunnelling or encapsulation

Abstract

An example method for to inter-pod traffic redirection and handling in a multi-pod network environment is provided and includes receiving a packet with an overlay header outgoing from a first pod, identifying the packet as redirected based on a source address in the overlay header indicating a second pod and a destination address in the overlay header indicating a third pod, the first pod being distinct from the second pod and the third pod, setting a redirection bit in the overlay header tagging the packet as redirected, and transmitting the packet to the third pod.

Claims

1. A method executed by a hardware translator in a multi-pod network environment, comprising:

receiving, at the translator located in a first pod, a packet from a second pod, wherein the packet comprises an overlay header having a destination address indicating the first pod, a source address indicating the second pod and a redirection bit indicating the packet as not redirected, wherein the packet comprises an underlay header indicating a destination endpoint;

rewriting the destination address in the overlay header to a local address of a proxy module in the first pod;

transmitting the packet to the proxy module, wherein the proxy module examines the underlay header and determines that the destination endpoint has moved to a third pod, wherein the proxy module rewrites the destination address in the overlay header to indicate the third pod and returns the packet to the translator;

receiving, at the translator, the packet from the proxy module, wherein the packet is outgoing from the first pod;

identifying the packet, by the translator, as redirected based on the source address in the overlay header indicating the second pod and the destination address in the overlay header indicating the third pod, the first pod being distinct from the second pod and the third pod;

rewriting, by the translator, the source address in the overlay header to indicate the first pod;

setting, by the translator, a redirection bit in the overlay header tagging the packet as redirected; and

transmitting the packet, by the translator, to the third pod.

2. The method of claim 1, further comprising:

receiving a second packet incoming into the first pod from the second pod, wherein the second pod packet comprises a second overlay header having a destination address indicating the first pod, a source address indicating the second pod, and a redirection bit indicating the packet as redirected;

identifying the second packet as redirected based on a value of the redirection bit in the second overlay header;

rewriting the source address and the destination address in the second overlay header to a local address of the proxy module in the first pod;

stripping the redirection bit from the overlay header; and

transmitting the second packet to the proxy module in the first pod.

3. The method of claim 2, wherein a destination switch flushes a data path of the second packet and does not learn the source address in the second overlay header based on the source address and the destination address in the second overlay header indicating the local address of the proxy module.

4. The method of claim 3, wherein the destination switch determines a corrected source address by a lookup of a local endpoint repository.

5. The method of claim 1, further comprising:

receiving, at the translator from the proxy module, a second packet outgoing from the first pod, wherein the second packet comprises a second overlay header having a destination address indicating the third pod and a source address indicating the local address of the proxy module;

identifying the second packet as not redirected based on a source address in the second overlay header indicating a local address in the first pod and the destination address in the second overlay header indicating the third pod;

clearing the redirection bit indicating that the packet is not redirected; and

transmitting the packet to the third pod.

6. The method of claim 1, further comprising:

receiving a second packet incoming into the first pod from the second pod, wherein the second packet comprises a second overlay header having a destination address indicating the first pod, a source address indicating the second pod, and a redirection bit indicating the packet as not redirected;

identifying the second packet as not redirected based on a value of the redirection bit in the second overlay header;

rewriting the destination address in the second overlay header to a local address of the proxy module in the first pod;

stripping the redirection bit from the overlay header; and

transmitting the second packet to the proxy module in the first pod.

7. The method of claim 6, wherein the redirection bit is cleared to zero to tag the packet as not redirected.

8. The method of claim 1, wherein the redirection bit is set to one to tag the packet as redirected.

9. The method of claim 1, wherein each pod comprises a fabric including a plurality of spine switches interconnected to leaf switches, wherein the leaf switches are connected to endpoints that generate or terminate packets in a data plane.

10. Non-transitory tangible media that includes instructions for execution by a processor of a translator in a multi-pod network environment to perform operations comprising:

receiving, at the translator located in a first pod, a packet from a second pod, wherein the packet comprises an overlay header having a destination address indicating the first pod, a source address indicating the second pod and a redirection bit indicating the packet as not redirected, wherein the packet comprises an underlay header indicating a destination endpoint;

rewriting the destination address in the overlay header to a local address of a proxy module in the first pod;

stripping the redirection bit from the overlay header;

transmitting the packet to the proxy module, wherein the proxy module examines the underlay header and determines that the destination endpoint has moved to a third pod, wherein the proxy module rewrites the destination address in the overlay header to indicate the third pod and returns the packet to the translator;

receiving, at the translator, the packet from the proxy module, wherein the packet is outgoing from the first pod;

identifying the packet, by the translator, as redirected based on the source address in the overlay header indicating the second pod and the destination address in the overlay header indicating the third pod, the first pod being distinct from the second pod and third pod;

rewriting, by the translator, the source address in the overlay header to indicate the first pod;

setting, by the translator, a redirection bit in the overlay header tagging the packet as redirected; and

transmitting the packet, by the translator, to the third pod.

11. The media of claim 10, wherein the operations further comprise:

receiving a second packet incoming into the first pod from the second pod, wherein the second packet comprises a second overlay header having a destination address indicating the first pod, a source address indicating the second pod, and a redirection bit indicating the packet as redirected;

identifying the second packet as redirected based on a value of the redirection bit in the second overlay header;

rewriting the source address and the destination address in the second overlay header to a local address in the first pod;

stripping the redirection bit from the overlay header; and

transmitting the second packet to the local address in the first pod.

12. The media of claim 11, wherein a destination switch flushes a data path of the second packet and does not learn the source address in the second overlay header based on the source address and the destination address in the second overlay header indicating the local address of the proxy module.

13. The media of claim 10, wherein the operations further comprise:

receiving, at the translator from the proxy module, a second packet outgoing from the first pod, wherein the second packet comprises a second overlay header having a destination address indicating the third pod and a source address indicating the local address of the proxy module;

identifying the second packet as not redirected based on a source address in the second overlay header indicating a local address in the first pod and the destination address in the third overlay header indicating the third pod;

clearing the redirection bit indicating that the packet is not redirected; and

transmitting the packet to the third pod.

14. The media of claim 10, wherein the operations further comprise:

receiving a second packet incoming into the first pod, wherein the wherein the second packet comprises a second overlay header having a destination address indicating the first pod, and a redirection bit indicating the packet as not redirected;

identifying the second packet as not redirected based on a value of the redirection bit in the second overlay header;

rewriting the destination address in the second overlay header to the local address of the proxy module in the first pod;

stripping the redirection bit from the overlay header; and

transmitting the second packet to the local address in the first pod.

15. An apparatus in a first pod of a multi-pod network environment, comprising:

a memory element for storing data; and

a processor, wherein the processor executes instructions associated with the data, wherein the processor and the memory element cooperate, such that the apparatus is configured as a translator for;

receiving a packet from a second pod, wherein the packet comprises an overlay header with a destination address indicating the first pod, a source address indicating the second pod and a redirection bit indicting the packet as not redirected, wherein the packet comprises an underlay header indicating a destination endpoint;

rewriting the destination address in the overlay header to a local address of a proxy module in the first pod;

stripping the redirection bit from the overlay header;

transmitting the packet to the proxy module, wherein the proxy module examines the underlay header and determines that the destination endpoint has moved to a third pod, wherein the proxy module rewrites the destination address in the overlay header to indicate the third pod and returns the packet to the translator;

receiving, at the translator, the packet from the proxy module, wherein the packet is outgoing from the first pod;

identifying the packet as redirected based on the source address in the overlay header indicating the second pod and the destination address in the overlay header indicating the third pod, the first pod being distinct from the second pod in the third pod;

rewriting, by the translator, the source address in the overlay header to indicate the first pod;

setting, by the translator, a redirection bit in the overlay header tagging the packet as redirected; and

transmitting the packet, by the translator, to the third pod.

16. The apparatus of claim 15, further configured for:

receiving a second packet incoming into the first pod from the second pod, wherein the second packet comprises a second overlay header having a destination address indicating the first pod, a source address indicating the second pod, and a redirection bit indicating the packet as redirected;

identifying the second packet as redirected based on a value of the redirection bit in the second overlay header;

rewriting the source address and the destination address in the second overlay header to a local address of the proxy module in the first pod;

stripping the redirection bit from the overlay header; and

transmitting the second packet to the local address in the first pod.

17. The apparatus of claim 16, wherein a destination switch flushes a data path of the second packet and does not learn the source address in the second overlay header based on the source address and the destination address in the second overlay header indicating the local address of the proxy module.

18. The apparatus of claim 15, further configured for:

receiving from the proxy module, a second packet outgoing from the first pod;

wherein the second packet comprises a second overlay header having a destination address indicating the first pod, a source address indicating the local address of the proxy module;

identifying the second packet as not redirected based on a source address in the second overlay header indicating the local address in the first pod and the destination address in the second overlay header indicating the third pod;

clearing the redirection bit indicating that the packet is not redirected; and

transmitting the packet to the third pod.

19. The apparatus of claim 15, further configured for:

receiving a second packet incoming into the first pod from the second pod, wherein the second packet comprises a second overlay header having a destination address indicating the first pod, a source address indicating the second pod, and a redirection bit indicating the packet as not redirected;

identifying the second packet as not redirected based on a value of the redirection bit in the second overlay header;

rewriting the destination address in the second overlay header to the local address of the proxy module in the first pod;

stripping the redirection bit from the overlay header; and

transmitting the second packet to the local address in the first pod.