The 10 Gigabit optical port can be used to connect a gigabit module

A 10 Gigabit SFP+ port can accept a Gigabit SFP optical module, but the link will operate at 1 Gbps, and a 10G SFP+ module cannot run on a 1G SFP port.Compatibility Overview10G SFP+ ports are designed for 10 Gbps transmission but are physically compatible with standard 1G SFP modules. When a 1G SFP module is inserted into a 10G SFP+ port, the port will downgrade its speed to 1 Gbps to match the module, allowing the connection to work normally .1G SFP ports on Gigabit switches cannot accept 10G SFP+ modules. The 10G module cannot auto-negotiate down to 1 Gbps because SFP+ modules are designed for higher-speed operation and use different signaling, so the connection will fail .Practical ConsiderationsSome 10G switches may lock the SFP+ port at 1G when a 1G SFP module is inserted, requiring a switch reset or configuration command to restore normal operation .Using a 10G SFP+ module on a 1G SFP port is not supported due to rate mismatch and lack of auto-negotiation for optical signals .To ensure stable and efficient network communication, it is important to match the optical module speed with the port speed. Using mismatched modules may work in some cases but will not utilize the full bandwidth of the 10G module .Summary10G SFP+ port + 1G SFP module → works at 1 Gbps1G SFP port + 10G SFP+ module → does not workAlways verify switch specifications and dual-rate support before connecting different-speed modules to avoid network issues . This ensures proper operation and avoids potential rate mismatches or link failures in fiber-optic networks.