Current setup is (one) core switch 6509 with default route to (one) ISP router( isp router not under my administration, i have to ask for specific configuration changes).
Soon We will migrate the core to stackwise virtual pair of c9407s.
How do i achieve dual homing to the same ISP , incase active switch fails ?
If the Device is Singled Home connection you will not get that HA availability.
What you can do from Up-link router have 2 Interface, stretch that to other switch in theirs case you are sure, it is fully meshed and resilience can be taken care.
Do you have 2 routers for ISP, or both ISP terminating with 1 router.
what is the existing arrangement.
If have only 1 router, 1st image you provided should for you.
If you have 2 routers, that need also required dual homes connection to south bound switches to get resilience setup.
Unfortunaley not enough information at this time to provide an acurate suggestion howerver you have options to employ various desgins for HA even routing resilency but for that can you provide some more detail surrounding the connectivity towards your ISPs.
Single ISP: Dual links, Dual routers at both ends
The connectivity towards ISP router is via a static default route currently.
What are my config options when i connect our new core switches(stackwise virtual) with 2 different ISP routers of single provider ? I understand i had to use bgp ?
What bgp config would be ideal in my senario ?