by using port channel with vlans trunked in it from the router to the stack using diffrent physical switchport and switch for each link will provide you with good level of physical and logical rednandacy
however using two links for the Internet is something that you need to control using routing, PBR or both with IPSLA for best path selection or loadbalancing
I have such design in my environment and it work just fine until now. The truth is that we don't care about load balancing of the Internet traffic right now as we have 2 x 100Mbits Internet and none of the lines are yet overloaded. We let BGP (best path) to decide the best outgoing line.
When one of the line will get over utilized, then I think we'll do some of the solutions proposed by marwanshawi.
Additionally, would it be possible to do something similar with non Stackwise switches as well?
We have our /22 divided into /24's each on a respective vlan and trunked into the border routers. Each has a subinterface with an IP in the respective vlan and an HSRP IP for each as well. If I were to add the cross links where RouterA is trunked to SwitchB and vice versa would the router's subinterfaces on this link require IP's as well or would it perform L2 traffic switching to SwitchB if SwitchA should fail?
What I'm wondering is, would the router switch between subinterfaces if one of the subinterfaces was IP'd and the other wasn't?
Here's an example config where the same uplinking strategy is used but without stackwise switches and without port channeling on the router.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...