可以看看某乎的回答:"一级路由下的设备怎么访问二级路由下的设备?" (https://link.segmentfault.com/?enc=vq1LFqAQQDLfIm64xweX1Q%3D%3D.%2FgEi4BvrPfFeWWjdcP3kDcs%2BuDM9bVnHYFKPcrmAA0yD98kOg4Fo4tGHM82RWYg6)
"二级路由怎么设置,才能让两个路由下的设备互相访问?" (https://link.segmentfault.com/?enc=EP3XqdL9xAs4WVDVwrzlmg%3D%3D.Zpb11gm7aH5CzmMEw6EkXZIbGcvS%2B%2FBfMBJVOZLnPDeYcM%2Be4zO606NazpUGs29l)