A one-arm data center topology routes traffic between internal sub-nets and between a sub-net and an outside network through a common chain of services. The data center topology employs layer 4 services on a common chassis or platform to provide routing and firewall services while reducing the number of devices necessary to implement the data center and simplifying configuration. Load balancing is provided by a load balancing device. In the one-arm topology, policy based routing or client network address translations or NAT pushes traffic to the CSM.