A security gateway includes packet routing policies, each including a host network address, an application network address, and a forwarding interface. In routing data packets of an application session, the security gateway: recognizes the application session between a network and an application; determines a user identity from an application session record for the application session; determines packet routing policies applicable to the application session based on the user identity; receives a data packet for the application session, including a source network address and a destination network address; compares the source network address with the host network address, and the destination network address with the application network address; and in response to finding a match between the source network address and the host network address, and between the destination network address and the application network address, processes the data packet using the forwarding interface of the packet routing policy.