52-Port Gigabit Stackable Smart Managed Switch with 4 x 10G SFP+ Ports - 48 x 10/100/1000Mbps ports- 4 x 10G SFP+ ports- Physical stack of up to 9 units via two/four 10G ports- Supports long-distance stacking over fiber- 80 Gbps per device physical stacking bandwidth- D-Link Single IP Management (SIM), Up to 32 units per virtual stack- 2 x smart fan- 6 kV surge protection for Ethernet ports- Dying Gasp- Ethernet Ring Protection Switching (ERPS)- Redundant power supply (RPS) support- Layer 3 features including Max. 1024 ARP entries (Supports 255 static ARP entries), Gratuitous ARP, IPv6 Neighbor Discovery (ND), 64 IP interfaces, Default route, Static route (64 IPv4 static routes / 32 IPv6 static routes)- Comprehensive Security Features including Access Control Lists (ACLs), D-Link Safeguard Engine, BPDU attack protection, ARP spoofing prevention, IP-MAC-Port Binding (IMPB), DoS attack prevention, IEEE 802.1X port-based Access Control, WAC/MAC-based Access Control, Guest VLAN- 802.1ag CFM- 802.3ah Ethernet Link OAM- SNMP v1/v2c/v3- RMON v1/v2- LLDP/LLDP-MED