Routing to new internet connection

[davros1000]

Hello

We have just recently put in a new internet connection and I have been asked to test traffic going to the new router without making any changes to the switches (such as static routes).

We currently have a CentOS test server connected to a L3 core switch, the two routers are then connected to the core switch. The CentOS server's gateway is the core switch, this is on a different subnet to the two routers. I can ping the new router ok from the test server. Is there any way that I can adjust traffic from certain IP's to use this new router, despite it not being on the same subnet as the gateway. I would think that I would need to create a static route for it on the switch first.

Thanks