What are the potential problems with single-arm routing for data forwarding? How to solve them?

There are two problems in using single-arm routing to achieve data forwarding: 1. The router and switch are connected through a link, which is easy to become a single point of network failure, resulting in communication interruption between VLANs. 2. The communication between each VLAN is carried by a “einzel” link. Der “single-arm” link may become a bottleneck in traffic transmission. The solution is to replace it with a three-layer switch to achieve inter-VLAN routing.