1. pt做不了vpc的模拟实验
2. 核心和汇聚层之间这样组件vpc没有什么问题，应该是可以起得来的，但是vpc的domain不能一致。
3.至于汇聚层和核心层之间三层互联，跑ospf，应该可以搞，基于你的拓扑，可以创建单独的vlan interface来建立三层邻居关系。没有实际真么搞过，具体可以的可以参考nexus的 configuration guide，或者 vpc best practices（第二个链接）文档中L3 and vPC部分
Strong Recommendations:
To build L3 backup routing path, use the following options listed by descending order of preference:
● Use a dedicated Layer 3 point-to-point link between the vPC peer devices to establish a Layer 3 backup
path to the core.
● Use the already existing Layer 2 port-channel trunk ISL (Inter Switch Link) for non-vPC VLAN and create
dedicated VLAN/SVI to establish a Layer 3 neighborship
● Use vPC peer-link and create dedicated VLAN/SVI to establish a Layer 3 neighborship (least recommended
solution)
另外有限制的就是支持的版本，该功能在不同型号上起始支持版本号不一样，需要参考相应文档
https://www.cisco.com/c/en/us/support/docs/ip/ip-routing/118997-technote-nexus-00.html
https://www.cisco.com/c/dam/en/us/td/docs/switches/datacenter/sw/design/vpc_design/vpc_best_practices_design_guide.pdf
