1. A method for securing a managed forwarding element (MFE) that operates in a data compute node (DCN) executing in a host machine, the method comprising: receiving a notification that the MFE is loaded on the DCN, the MFE for implementing a set of logical forwarding elements of a logical network that logically connects the DCN to a plurality of other DCNs; and securing the MFE by isolating, in a physical memory of the host machine, executable code and data of the MFE from executable code and data of other applications that execute in the DCN.