Can the switch be directly connected to the optical modem

The direct connection between the switch and the optical modem is technically feasible, but the connection method and network effect in actual operation may vary depending on the working mode of the optical modem (routing mode or bridging mode). The following will provide a detailed analysis from the aspects of connection scheme, precautions, operation steps, etc., to help you plan your home or business network layout reasonably.
In terms of connection scheme, different working modes of the optical modem correspond to different networking strategies. When the optical modem is in the common home default routing mode, simply connect the LAN port of the optical modem to any port of the switch through a network cable. In this mode, the optical modem is responsible for core functions such as dialing, NAT translation, and IP address allocation (DHCP), while the switch only serves as an extension tool for the number of LAN ports. All access devices share the performance of the optical modem. This solution is suitable for scenarios where no more than 10 wired devices are connected, such as computers, televisions, and NAS, and network performance requirements are not high. When the optical modem switches to bridging mode (which usually requires contacting the operator for assistance or manually setting up), the connection method changes to connecting the optical modem LAN port to the switch via a network cable, and then connecting the switch to the router's WAN port. At this time, the optical modem is only responsible for optical signal conversion, and the routing function is executed by the router. The switch not only extends the LAN port of the optical modem, but also supports parallel connection of multiple routers, which is suitable for Mesh networking, enterprise multi WAN port access, or advanced users who need to customize complex network topologies.
There are several key considerations to pay attention to when implementing connections. In terms of performance, the NAT forwarding capability of optical cats is generally limited (usually not exceeding 800Mbps). When there are too many connected devices or network bandwidth exceeds 300Mbps, it is easy to encounter problems such as network lag and latency spikes. In this case, it is recommended to use routers with stronger NAT performance instead of switches; In terms of network configuration, if a router is connected under the switch, the DHCP service of the secondary router must be turned off and switched to AP mode, otherwise it will cause confusion in IP address allocation due to conflicts between two DHCP servers; At the signal coverage level, the switch itself does not have wireless signal transmission function. To achieve WiFi coverage, an additional AP must be connected or a wireless router set to AP mode must be used; For enterprise level network requirements, ordinary home switches do not support VLAN isolation function, and all devices are in the same broadcast domain. Therefore, enterprise users need to use management switches to divide VLANs and achieve business isolation.
Taking the optical modem routing mode as an example, the specific steps are as follows: first, make hardware connections and connect the gigabit LAN port of the optical modem to the Uplink port of the switch through an Ethernet cable (if there is no Uplink port, any port can be connected); Then connect the computer, TV, NAS and other devices to other ports of the switch through Ethernet cables; Subsequently, set the IP acquisition method for all devices to DHCP automatic acquisition (default allocation of 192.168.1. x network segment for optical modem); Finally, open the browser to access the webpage and verify if the network is connected properly.
However, not all scenarios are suitable for direct connection of switches to optical cats. When the number of devices exceeds 10, the performance of the optical modem may crash due to excessive load. In this case, the connection method of "optical modem → high-performance router → switch" should be adopted; If there is a demand for network latency sensitivity in games, live streaming, etc., the limited NAT forwarding capability of Guangmao will lead to high latency. It is recommended to set Guangmao to bridging mode and use it with a game router; For Mesh networks that require seamless roaming functionality, switches cannot manage WiFi and must adopt an architecture of "optical modem → main Mesh router → switch"; For the network coverage requirements of multiple floors, a single optical modem's WiFi signal is difficult to meet. APs can be deployed on each floor and connected to switches.
Overall, the ultimate network solution is a combination of "router+switch+AP": routers undertake core routing functions such as dial-up, NAT translation, and DHCP allocation, fully leveraging their high-performance advantages; Switches focus on the expansion of wired interfaces; AP provides high-quality and stable WiFi coverage. This architecture can ensure network performance while meeting diverse connectivity requirements. Therefore, switch direct connection optical modem is suitable for simple wired device expansion scenarios, and in complex scenarios with many devices, high bandwidth requirements, or sensitivity to network latency, introducing high-performance routers for relay is a better choice. At the same time, it is necessary to configure network parameters reasonably according to the working mode of the optical modem and expand wireless coverage as needed in order to build an efficient and stable network environment.