28-Port 10G Multi-Gigabit Layer 3 Stackable Managed Switch with 25G Uplinks 24 x 100M/1G/2.5G/5G/10GBASE-T ports 4 x 10/25G SFP28 ports Physical Stacking of up to 9 units with 200Gbps stacking bandwidth Ring or Chain topology Virtual Stacking with SIM up to 32 units per stack Switching Capacity 680 Gbps 5-speed smart fan design automatically adjusts according to device operating temperature Redundant power supply (RPS) support Ethernet Ring Protection Switching (ERPS) Embedded 6 kV surge protection on all Ethernet ports IEEE 802.1D/802.1w/802.1s Spanning Tree Loopback Detection (LBD) L3 Features including Static Route, RIP/RIPng, OSPFv2/v3 IEEE 802.3ah Ethernet Link OAM IEEE 802.1ag/ITU-T Y.1731 Service OAM