According to your situation, you need to use NAT technology, according to the private IP address range of Class B IP (172 5438+06.0.0-172 5438+0.255.255). Don't change DNS unless you change operators!

I offer you the following scheme: (based on NAT)

1. Divide VLAN (enough to eliminate broadcast storm) and use inter-VLAN routing (you are one-armed routing).

2. Match the interface of the router to the subinterface. Every VLAN? Correspond to a subinterface, and then configure encapsulation mode.

Is it equal to only changing the IP of the intranet? But do NAT on the route. DNS can remain unchanged.

The specific configuration depends on you! (remember! ! ! The interface between the switch and the router should be configured in trunk mode! ! ! ! )