28-Port Gigabit Stackable Smart Managed Switch including 4 10G SFP+ - 24 x 10/100/1000Mbps Auto-Negotiating Ports - 4 x 10G SFP+ ports - Physical Stacking up to 6 units per stack. Physical Stacking Bandwidth of 40Gb. Topology Linear or Ring. - Switch Capacity 128Gbps - D-Link Green 3.0, 802.3az - Virtual stacking up to 32 devices. - Static route - IPv6 Management/Ready Logo - Half-/Full-Duplex, auto-negotiation, Auto MDI/MDIX - IEEE 802.3x Flow Control - 802.3ad Link Aggregation - Asymmetric VLAN, Auto Voice VLAN, GVRP - 802.1p priority queues - MAC/IP filtering - MAC/IP-based ACL - 802.1X port-base Access Control, Port Security, traffic segmentation - D-Link Safequard Engine - D-Link Network Assist, web based management, compact CLI - Dual Image FW - 19" Rackmount Installation.