The following diagram shows a HG 3500 scenario for a fictitious customer in Frankfurt. It shows node 10-69-100 (Frankfurt-Bockenheim) and node 10-69-200 (Frankfurt-Sachsenhausen). Both systems have a common gateway board that should be configured as HG 3500. LEGK should be active on both systems (two local gateways). This constellation is relatively easy to explain because both nodes can be configured more or less symmetrically. The figure shows all necessary parameters. Node 10-69-100 is located in IP network 1.69.11.0/24 and node 10-69-200 is located in IP network 1.69.21.0/24. The networks reach each other over the routers Ra and Rb.