要配置交换机，需要先添加switch model? 需要增加add switch model 的原因，什么时候添加，在配置交换机之前？去UI 上确认如何添加。
To add a switch model, follow these steps:
Click Service > System Model,
Click the + icon, and select the switch model.
Configure the port numbers for different speeds.
Select the image that is used to install PICOS in switches during ZTP deployment. You need to upload the images beforehand as described in the Uploading and pushing images section.
Click Save.
Optional: 增加update switch model 的用处。