Tracing logical network packets through physical network

Abstract

Some embodiments provide a method for a network controller that manages several managed forwarding elements. The method receives a request to trace a specified packet having a particular source on a logical switching element. The method generates the packet at the network controller according to the packet specification. The generated packet includes an indicator that the packet is for a trace operation. The method inserts the packet into a managed forwarding element associated with the particular source. The method receives a set of messages from a set of managed forwarding elements that process the packet regarding operations performed on the packet.

1 - 29 . (canceled) 
     
     
         30 . A method for processing a flow trace packet at a particular managed forwarding element (MFE), the method comprising:
 receiving a flow trace packet having source and destination addresses in a logical network implemented by the particular MFE;   processing the flow trace packet based on the logical network addresses; and   sending a message to a network controller regarding the processing of the flow trace packet, the message comprising (i) data identifying the particular MFE and (ii) data identifying an action taken by the particular MFE based on the processing of the flow trace packet.   
     
     
         31 . The method of  claim 30 , wherein receiving the flow trace packet comprises:
 receiving the flow trace packet from the network controller; and   receiving, from the network controller, a command specifying to process the flow trace packet as though the particular MFE received the flow trace packet via a particular physical port.   
     
     
         32 . The method of  claim 31 , wherein the particular physical port corresponds to a virtual machine (VM) associated with the source address of the flow trace packet. 
     
     
         33 . The method of  claim 31 , wherein:
 processing the flow trace packet comprises encapsulating the packet with tunnel information for a particular tunnel; and   the data identifying the action taken by the particular MFE comprises an identifier for the particular tunnel.   
     
     
         34 . The method of  claim 30 , wherein receiving the flow trace packet comprises receiving the flow trace packet via a tunnel from another MFE. 
     
     
         35 . The method of  claim 34 , wherein:
 processing the flow trace packet comprises determining that the flow trace packet is for delivery to a particular port based on the destination address of the flow trace packet; and   the data identifying the action taken by the particular MFE comprises a port identifier for the particular port.   
     
     
         36 . The method of  claim 35 , wherein the particular MFE does not deliver the flow trace packet to the particular port based on a flow trace indicator in the flow trace packet. 
     
     
         37 . The method of  claim 30 , wherein the flow trace packet comprises (i) a flow trace indicator that specifies that the flow trace packet is for a flow tracing operation and (ii) a controller identifier indicating the network controller to which the particular MFE sends the message. 
     
     
         38 . The method of  claim 30 , wherein the network controller receives messages from a plurality of MFEs, including the particular MFE, that process the flow trace packet. 
     
     
         39 . The method of  claim 30  further comprising sending a copy of the flow trace packet to the network controller along with the message. 
     
     
         40 . A non-transitory machine-readable medium storing a particular managed forwarding element (MFE) which when executed by at least one processing unit processes a flow trace packet, the program comprising sets of instructions for:
 receiving a flow trace packet having source and destination addresses in a logical network implemented by the particular MFE;   processing the flow trace packet based on the logical network addresses; and   sending a message to a network controller regarding the processing of the flow trace packet, the message comprising (i) data identifying the particular MFE and (ii) data identifying an action taken by the particular MFE based on the processing of the flow trace packet.   
     
     
         41 . The non-transitory machine-readable medium of  claim 40 , wherein the set of instructions for receiving the flow trace packet comprises sets of instructions for:
 receiving the flow trace packet from the network controller; and   receiving, from the network controller, a command specifying to process the flow trace packet as though the particular MFE received the flow trace packet via a particular physical port.   
     
     
         42 . The non-transitory machine-readable medium of  claim 41 , wherein the particular physical port corresponds to a virtual machine (VM) associated with the source address of the flow trace packet. 
     
     
         43 . The non-transitory machine-readable medium of  claim 41 , wherein:
 the set of instructions for processing the flow trace packet comprises a set of instructions for encapsulating the packet with tunnel information for a particular tunnel; and   the data identifying the action taken by the particular MFE comprises an identifier for the particular tunnel.   
     
     
         44 . The non-transitory machine-readable medium of  claim 40 , wherein the set of instructions for receiving the flow trace packet comprises a set of instructions for receiving the flow trace packet via a tunnel from another MFE. 
     
     
         45 . The non-transitory machine-readable medium of  claim 44 , wherein:
 the set of instructions for processing the flow trace packet comprises a set of instructions for determining that the flow trace packet is for delivery to a particular port based on the destination address of the flow trace packet; and   the data identifying the action taken by the particular MFE comprises a port identifier for the particular port.   
     
     
         46 . The non-transitory machine-readable medium of  claim 45 , wherein the particular MFE does not deliver the flow trace packet to the particular port based on a flow trace indicator in the flow trace packet. 
     
     
         47 . The non-transitory machine-readable medium of  claim 40 , wherein the flow trace packet comprises (i) a flow trace indicator that specifies that the flow trace packet is for a flow tracing operation and (ii) a controller identifier indicating the network controller to which the particular MFE sends the message. 
     
     
         48 . The non-transitory machine-readable medium of  claim 40 , wherein the network controller receives messages from a plurality of MFEs, including the particular MFE, that process the flow trace packet. 
     
     
         49 . The non-transitory machine-readable medium of  claim 40 , wherein the program further comprises a set of instructions for sending a copy of the flow trace packet to the network controller along with the message.