| Switch type | Managed |
| Quality of Service (QoS) support | Y |
| Basic switching RJ-45 Ethernet ports quantity | 4 |
| USB 2.0 ports quantity | 1 |
| Networking standards | IEEE 802.1D |
| 10G support | N |
| IP routing | Y |
| Link aggregation | Y |
| Rate limiting | Y |
| VLAN support | Y |
| Access Control List (ACL) | Y |
| IGMP snooping | Y |
| Security algorithms | 802.1x RADIUS |
| Management protocols | Telnet, Simple Network Management Protocol Version 3 (SNMPv3), Secure Shell (SSH) Protocol, CommandLine Interface (CLI), and HTTP management |
| Rack mounting | N |
| Stackable | N |
| Product colour | Black |
| LED indicators | Y |
| Electromagnetic compatibility | 47CFR, AS/NZS CISPR22 2, CISPR22, EN55022, ICES003, EN61000-3-2, KCC, EN55024, KN24 |
| Internal memory | 1024 MB |
| Flash memory | 2048 MB |
| Power supply included | Y |
| Number of power supply units | 1 |
| AC input voltage | 100 - 240 V |
| AC input frequency | 50 - 60 Hz |
| Power over Ethernet (PoE) | N |
| Operating temperature (T-T) | 0 - 50 °C |
| Storage temperature (T-T) | -40 - 70 °C |
| Operating relative humidity (H-H) | 5 - 95% |
| Width | 228.6 mm |
| Depth | 241.3 mm |
| Height | 43.2 mm |
| Weight | 1.2 kg |
| Description |
| Cisco C921-4P. Switch type: Managed. Basic switching RJ-45 Ethernet ports quantity: 4, USB 2.0 ports quantity: 1. Networking standards: IEEE 802.1D |