Some embodiments provide a method for securing a managed forwarding element (MFE) that operates in a data compute node (DCN) executing in a host machine. The method receives a notification that the MFE is loaded on the DCN. The MFE is for implementing a set of logical forwarding elements of a logical network that logically connects the DCN to several other DCNs. The method secures 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.