What is a combo port in Ethernet?
A combo port is an Ethernet interface featuring RJ45 and SFP ports. This optoelectronic multiplexing interface supports two physical layers and shares the same port fabric and switch fabric. The two different ports cannot be used at the same time. For instance, if an SFP port is automatically activated, then RJ45 is disabled and vice versa. The SFP port requires optical modules and is usually connected to patch cables, whereas the RJ45 port is connected to twisted pairs. You will see an interface identifier on the switch panel of switches with combo ports.
The switches with combo ports are distinguished into two categories – single combo ports and dual combo ports. The single combo port switches feature two Ethernet ports that offer one port view. This type of switch can be a layer 3 or 2 interface and a user can perform the state-switching operation using a single port view. However, dual combo ports offer two different port views through two Ethernet ports. Generally, dual combo port switches are used as layer 2 interfaces and allow users to switch the status of ports on the electrical or optical port view. Get to know more about Different Types of Ethernet Switch Ports here.