HANDLING REVERSE NAT IN LOGICAL L3 ROUTING

• US 20130148543A1
• Filed: 02/01/2013
• Published: 06/13/2013
• Est. Priority Date: 08/17/2011
• Status: Active Grant

• Current Assignee: Nicira Incorporated (Broadcom, Inc.)
• Original Assignee: Nicira Incorporated (Broadcom, Inc.)
• Inventors: Koponen, Teemu, Casado, Martin, Thakkar, Pankaj, Zhang, Ronghua
• Granted Patent: US 9,185,069 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04L 41/0803 Configuration setting
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/54 Organization of routing tables
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]
• CPC Class Codes: H04L 61/256 NAT traversal
• CPC Class Codes: H04L 61/2592 using tunnelling or encapsulation

Abstract

A non-transitory machine readable medium storing a program that configures first and second managed forwarding elements to perform logical L2 switching and L3 routing is described. The program generates a first set of flow entries for configuring the first managed forwarding element to (1) perform a network address translation (NAT) processing on a first packet and (2) send, to a second managed switching element. The first packet and information indicate that the NAT processing has been performed on the first packet. The program generates a second set of flow entries for configuring the second managed forwarding element to (1) skip performing a logical L3 processing on a second packet to be sent to the first managed forwarding element in response to receiving the first packet and (2) send the second packet to the first managed switching element.

Claims

1. A non-transitory machine readable medium storing a program which when executed by at least one processing unit configures first and second managed forwarding elements to perform logical L2 switching and L3 routing, the program comprising sets of instructions for:

generating a first set of flow entries for configuring the first managed forwarding element to (i) perform a network address translation (NAT) processing on a first packet and (ii) send, to a second managed switching element, the first packet and information indicating that the NAT processing has been performed on the first packet.

generating a second set of flow entries for configuring the second managed forwarding element to (i) skip performing a logical L3 processing on a second packet to be sent to the first managed forwarding element in response to receiving the first packet and (ii) send the second packet to the first managed switching element.

2. The machine readable medium of claim 1, wherein the first set of flow entries is further for configuring the first managed forwarding element to perform the logical L3 processing on the first packet before sending the first packet to the second managed forwarding element.

3. The machine readable medium of claim 1, wherein the logical L3 processing comprises identifying a port of a logical router that corresponds to an L2 domain to which a source of the first packet belongs.

4. The machine readable medium of claim 1, wherein the first set of flow entries is further for configuring the first managed forwarding element to perform a logical L2 processing for a first logical L2 domain on the first packet before sending the first packet to the second managed forwarding element.

5. The machine readable medium of claim 4, wherein the logical L2 processing for the first logical L2 domain comprises identifying a port of a logical forwarding element for the first logical L2 domain, the port corresponding to a second logical L2 domain.

6. The machine readable medium of claim 4, wherein the second set of flow entries is further for configuring the second managed forwarding element to perform the logical L2 processing for a second logical L2 domain on the first packet upon receiving the first packet from the first managed forwarding element.

7. The machine readable medium of claim 4, wherein the second set of flow entries is further for configuring the second managed forwarding element to skip performing the logical L2 processing for the second logical L2 domain on the second packet before sending the second packet to the first managed forwarding element.

8. For a network controller for managing managed forwarding elements that forward data in a network, a method for configuring a first managed forwarding element that sends a first packet to a second managed forwarding element, the method comprising:

configuring the first managed forwarding element to perform a network address translation (NAT) processing on a first packet; and

configuring the first managed forwarding element to send, to a second managed switching element, the first packet and information indicating that the NAT processing has been performed on the first packet,

wherein the second managed switching element, based on the information, does not perform the logical L3 processing on a second packet to be sent to the first managed forwarding element in response to receiving the first packet.

9. The method of claim 8, wherein configuring the first managed forwarding element comprises configuring the first managed forwarding element to perform a logical L3 processing on the first packet before sending the first packet to the second managed forwarding element.

10. The method of claim 8, wherein the second managed forwarding element does not perform the logical L3 processing on the second packet before sending the second packet to the first managed forwarding element.

11. The method of claim 8, wherein configuring the first managed forwarding element comprises configuring the first managed forwarding element to perform a logical L2 processing for a first logical L2 domain on the first packet before sending the first packet to the second managed forwarding element.

12. The method of claim 11, wherein the second managed forwarding element performs the logical L2 processing for a second logical L2 domain on the first packet upon receiving the first packet from the first managed forwarding element.

13. The method of claim 12, wherein the second managed forwarding element skips performing the logical L2 processing for the second logical L2 domain on the second packet before sending the second packet to the first managed forwarding element.

14. For a first managed forwarding element in a first host, a method for exchanging packets with a second managed forwarding element, the method comprising:

receiving, from a network controller a network controller for managing managed forwarding elements that forward data in a network, a set of flow entries defining forwarding behavior of the first managed switching element;

receiving, from the second managed forwarding element, a first packet and information indicating that a network address translation (NAT) processing has been performed on the first packet by the second managed forwarding element;

in response to receiving the first packet, send a second packet to the second managed forwarding element without performing a logical L3 processing on the second packet; and

performing the logical L3 processing on a third packet to be sent to a third managed forwarding element.

15. The method of claim 14, wherein the logical L3 processing comprises identifying a port of a logical router that corresponds to a logical L2 domain of a given packet to send.

16. The method of claim 15, wherein the second managed forwarding element performs a logical L2 processing for a second logical L2 domain on the second packet upon receiving the second packet from the first managed forwarding element.

17. The method of claim 15, wherein the second managed forwarding element performs a logical L3 processing on the second packet upon receiving the second packet from the first managed forwarding element.

18. The method of claim 15 further comprising performing the logical L2 processing for the first logical L2 domain on the third packet before sending the third packet to the third managed forwarding element.

19. The method of claim 18, wherein the third managed forwarding element performs the logical L2 processing on the third packet upon receiving the third packet from the first managed forwarding element.

20. The method of claim 18 further comprising configuring the first managed forwarding element to perform a logical L3 processing on the third packet before sending the third packet to the third managed forwarding element.

21. The method of claim 20, wherein the third managed forwarding element does not perform the logical L3 processing on the third packet upon receiving the third packet from the first managed forwarding element.