In addition to the common ports, there is a port called “combo port” on the Ethernet switches. To many newbies, combo ports always make them feel confused as there have been many Gigabit Ethernet ports and SFP slots for used on the switches. What is combo port and what does it mean for your network? How can I used it? A lot of such questions on combo ports are coming all the time. Don’t worry, if you happened to be confused with this, the following text will tell you the answer.
What Is Combo Port and What Does It Mean for Your Network?
In simple terms, a combo port is considered as a single interface with dual front ends, i.e. an RJ-45 connector and an SFP (Small Form Pluggable) module (also called Mini-GBIC) connector. In other words, it is a compound port which can support two different physical, share the same switch fabric and port number. But the two different physical ports can only be used simultaneously. That means if the SFP port is being used, then the corresponding copper port is automatically disabled and vice versa. For example, a switch has 8 x 10/100/1000TX ports and 2 Gigabit Ethernet Combo ports, therefore it could be configured to have 10 copper ports or 9 copper ports & 1 fiber port, or 8 copper ports & 2 fiber ports, etc.
A Combo port is a way to provide different types of connectivity without taking up unused switch fabric, giving users the power and flexibility to configure their switch for their unique application requirements.
Rules for Using the Combo Port Pairs
When using the combo port pairs, some rules should be followed:
- You may use either the twisted pair port or SFP slot of a combo port pair, but not both at the same time.
- If you connect both the twisted pair port and SFP slot of a combo port pair to network devices, the SFP slot takes priority and the twisted pair port is blocked.
- The SFP slot becomes active when the SFP transceiver establishes a link to a network device.
- The twisted pair port and SFP slot of a combo port pair share the same settings, such as VLAN (Virtual Local Area Network) assignments, access control lists, and spanning tree.
- Reference the SFP switch instruction to configure your combo ports according to your requirement.