Methods and systems for balancing load among firewall security devices are provided. According to one embodiment, a switch maintains a session table the session entries of which represent established traffic sessions between a source and a destination and form an association between the traffic session and a particular firewall security device (FSD). Responsive to receiving a packet of a first traffic session on a first port, a determination is made whether there exists a matching session entry. Responsive to a negative determination, a load balancing function is performed to select an FSD with which to associate the first traffic session and a corresponding reverse second traffic session. After processing of the packet by the selected FSD and receipt of the packet at a second port, a session entry is installed within the session table for the second traffic session and which associates the selected FSD with the second traffic session.