Asymmetric connection with external networks

A non-transitory machine readable medium storing a program which when executed by at least one processing unit of a host machine implements a first managed forwarding element in a managed network, the program comprising sets of instructions for:

• receiving a first packet from a second managed forwarding element, wherein the second managed forwarding element received the first packet from a particular source through a physical network element outside of the managed network;
• transmitting the first packet to a virtual machine hosted at the host machine;
• receiving a second packet from the virtual machine, wherein the second packet has a destination address of the particular source of the first packet;
• and
• transmitting the second packet directly to the physical network element via a connection between the host machine and the physical network element that does not include any intervening managed forwarding elements.

For a managed forwarding element that operates in a host machine to implement a logical network within a managed network, a method comprising:

• at the first managed forwarding element, receiving a first packet from a second managed forwarding element, wherein the second managed forwarding element received the first packet from a particular source through a physical network element outside of the managed network;
• transmitting the first packet from the first managed forwarding element to a virtual machine hosted at a host machine;
• at the first managed forwarding element, receiving a second packet from the virtual machine, wherein the second packet has a destination address of the particular source of the first packet;
• and
• transmitting the second packet directly from the first managed forwarding element to the physical network element via a connection between the host machine and the physical network element that does not include any intervening managed forwarding elements.