Stackable 4-Port Switch + combo Gig copper/SFP + 2 slots for 8 port uplinks
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Modular Architecture
The DGS-3212SR provides 4 10/100/1000BASE-T ports, 4 combo SFP GBIC slots and 2 open expansion slots. The expansion slots allow you to flexibly deploy this switch as a Stacking Master Switch, or as a stand-alone all-Gigabit switch. The expansion slots support the following expansion modules:
- DEM-540 4-port stacking module. This module allows you to stack up 4 D-Link DES-3226S stackable switches. With 2 DEM-540 modules installed in the expansion slots, you can stack up to 8 DES-3226S switches.
- DEM-340MG 4-port GBIC module. This module provides 4 SFP slots for installation of 4 Gigabit transceivers supporting short, medium and long distance fiber cables.
- DEM-340T 4-port copper Gigabit module. This module provides 4 10/100/1000BASE-T ports for 4 copper Gigabit connections.

Fault Tolerant Switch Stacking
With the DEM-540 stacking modules, the DGS-3212SR Stacking Master can stack up 8 D-Link stackable switches. The stacking scheme uses the star architecture, where packets are switched directly through the Stacking Master. This architecture provides for fault tolerance, as any single broken link between a switch and the Stacking Master will not affect the rest of the links of the stack. This compares favorably with the ring architecture, where a fail over link between any 2 switches can break the link of an entire stack.

Higher Performance Switch Stacking
Instead of a 2Gbps bandwidth shared by the entire stack in a ring architecture, the DGS-3212SR gives each of the switches on the stack a dedicated 2Gbps bandwidth from a Stacking Master stacking port. This brings the total bandwidth up to 16Gbps when 8 switches are stacked through the Stacking Master.

Scalable Expansion With 192 10/100BASE-TX & 12 Gigabit Ports
By stacking a DGS-3212SR with 8 DES-3226S switches, you can have as many as 192 10/100BASE-TX ports for departmental user connection, plus 12 Gigabit ports for server and backbone attachment. This architecture allows you to easily add switch units as your need grows, without making changes to your existing network hardware.

12-Port Collapsed Backbone
If you opt to use your DGS-3212SR as a stand-alone Gigabit switch, you can install up to 2 Gigabit modules in the expansion slots. This will give you 8 Gigabit ports, in addition to the 4 built-in 1000BASE-T/combo SFP ports, making it a total of 12 Gigabit ports. This type of deployment gives you a small collapsed backbone to which 12 switches and servers can be attached. All ports on the DGS-3212SR support jumbo frames to alleviate heavy network traffic. Copper and fiber cables can be deployed, depending on your selection of the port modules.

Redundant Power Support
The DGS-3212SR can be connected to an external power supply for redundant power backup purposes. In case the built-in internal power supply fails, the redundant power supply unit will automatically provide all the required power to ensure continuous operation.

VLANs for Enhanced Security & Performance
The DGS-3212SR supports 802.1Q and port-based VLANs to improve security and bandwidth utilization. This limits the broadcast domains and confines intra-group traffic within their segments. The switch also supports GVRP (GARP VLAN Registration Protocol) for automatic VLAN configuration distribution.

Advanced Network Access Management
802.1x features enable user authentication for each network access attempt. Port security features allow you to limit the number of MAC addresses per port in order to control the number of stations for each port. Static MAC addresses can be defined for each port to ensure only registered machines are allowed to access. By enabling both of these features, you can establish an access mechanism based on user and machine identities, as well as control the number of access stations.

Multi-Layer Access Control List (ACL)
Access Control Lists (ACL) allow the network administrator to define policies on network traffic control. The switch supports comprehensive and multi-layer ACLs, providing a powerful tool for network management. For example, the switch can be set to block malicious bulk traffic from specific clients based either on MAC or IP addresses. Or during a virus attack, the switch can be set to restrict its flooding based on a virus's unique pattern based on TCP/UDP port number.

Advanced CoS Support
The switch supports not only Layer 2 802.1p Priority Queue control, but also a variety of ways to prioritize network packets. Multi-layer information from L2 to L4 can be used to classify packet priorities. This function allows you to attach IP telephony devices or video servers to the switch to run delay-
sensitive applications like video conference. The DGS-3212SR supports up to 8 CoS (Class of Service) queues in the stand-alone mode, and up to 4 CoS queues in the Stacking Master mode.

Flexible Transmission Scheduling
The switch supports 2 methods of packet transmission scheduling: Strict Priority Queuing and Weighted Round-Robin (WRR). You can select to use Strict Priority Queuing to strictly enforce your priority queues, or WRR to address bandwidth limitations at peak time. WRR allows each queue to be assigned a different percentage of the output port's bandwidth, so that lower-priority queues are not denied access to buffer space and port bandwidth.

IGMP Snooping for Broadcast Control

The switch listens to IGMP (Internet Group Management Protocol) messages to build mapping table and associate forwarding filters. It dynamically configures the switch ports to forward IP multicast traffic only to those ports associated with multicast hosts.

Broadcast Storm Control

To prevent too many broadcast/multicast from flooding the network, broadcast/multicast storm control is configured to screen excessive traffic. Threshold values are available to control the rate limit for each port. Packets are discarded if the respective count exceeds the configured upper threshold in a given time interval. The possible range of upper threshold is from 0 to 255k packets per second.

Port Mirroring
This function allows you to mirror adjacent ports for the purpose of analyzing incoming and outgoing packets where packet patterns can be studied.

Spanning Tree For Redundant Backup Bridge Path

For mission critical environments with multiple switches supporting STP, you can configure the stack with a redundant backup bridge path, so transmission and reception of packets can be guaranteed in event of any fail-over switch on the network. The DGS-3212SR supports 802.1D Spanning Tree compatible, 802.1w Rapid Spanning Tree and 802.1s Multiple Spanning Tree.

Multiple Management Interfaces
SNMP v.1, v .3 network management is supported, using the built-in MIBs. RMON monitoring and SYSLOG are provided for effective central management. The switch also provides a Command Line Interface (CLI) and a Web-based GUI. CLI enables quick system configuration for administrators familiar with command line operation. The embedded Web-based interface allows you to easily access the switch from anywhere on the network and troubleshoot it in real-time. You can, for example, browse the MAC address table via the Web browser and perform searching to identify the location of any workstation. Port utilization graphs provide real-time traffic monitoring and diagnostic information.

(*) Multiple Spanning Tree is supported in the next firmware release.

General features

Device Ports
- 4 built-in 10/100/1000BASE-T ports
- 4 built-in combo GBIC (SFP) slots *
- RS-232 console port

* Use of the SFP GBIC will disable their corresponding built-in 10/100/1000BASE-T connections.

Number of Expansion Slots

Port Modules
(for expansion slots)
- DEM-540: 4 stacking ports supporting DES-3226S switches
- DEM-340MG: 4 SFP GBIC slots
- DEM-340T: 4 10/100/1000BASE-T ports

Port Standard/Function Support
- IEEE 802.3 10BASE-T/802.3u 100BASE-TX/802.3ab 1000BASE-T
- ANSI/IEEE 802.3 NWay auto-negotiation
- IEEE 802.3x Flow Control
- Port mirroring

GBIC (SFP) Support
- IEEE 802.3z 1000BASE-LX (DEM-310GT transceiver)
- IEEE 802.3z 1000BASE-SX (DEM-311GT transceiver)
- IEEE 802.3z 1000BASE-LH (DEM-314GT transceiver)
- IEEE 802.3z 1000BASE-ZX (DEM-315GT transceiver)

Forwarding Rate
17.8Mpps (max.)

Switch Fabric

Diagnostic LEDs
Per device:
- Power
- Console
Per RJ-45 port:
- Speed
- Link/Act

Per SFP port:
- Link/Act


- IEEE 802.1Q Tagged VLAN
- Port-based VLAN (non-overlapping)
- Asymmetric VLAN (L2 only)
- Maximum number of VLANs: 255

*  4 K maximum number of VLANs in stand-alone mode will be supported in next firmware upgrade

Priority Queues (CoS)
- Standard: IEEE 802.1p
- Number of queues: 4 per port (Stacking Master mode), 8 per port (stand- alone mode)

Traffic Classification (CoS)
Can be based on user-definable application types:
- Diffserv (DSCP)
- Port-based
- MAC address
- IP address
- TCP/UDP port number

Network Access Security
- 802.1x user authentication: port-based and MAC-based
- RADIUS client for 802.1x support
- SSH2 *
- SSL *
- Cisco-like port security
- Multi-layer Access Control List (ACL) based on:
   Diffserv (DSCP)
   IP address
   Protocol type
   TCP/UDP destination port number

* Functions available in next firmware upgrade

Spanning Tree
- 802.1D compatible
- 802.1w Rapid Spanning Tree
- 802.1s Multiple Spanning Tree *

* Multiple Spanning Tree supported in next firmware release

- IGMP v.1, v .2
- IGMP Snooping

Port Trunk
- Number of ports per trunk: 8 (max.)
- Number of trunk per switch: 6 (max.) (in DGS-3212SR stand-alone mode only)
- Trunking mode: static
- Operation mode: load sharing
- 802.3ad LACP support

Transmission Method


MAC Address Table
16K entries per device

MAC Address Learning
- Dynamic entries: automatic update
- Static entries: user-defined

Packet Filtering/Forwarding Rates (half duplex)
1,488,100 pps per port (max.)

RAM Buffer

1MB per device

Jumbo Frame Size
Up to 9,216bytes

Broadcast Storm Control
Rate control of Broadcast, unknown Multicast and Unicast packets

Configuration & Management
Management Support

- SNMP v.1, v .3
- Web-based management
- CLI (command line interface)
- RMON monitoring
- Telnet server
- Telnet remote control console
- Web GUI traffic monitoring
- Password enable
- Web MAC address browsing
- SNMP trap on MAC notification
- IP filtering on management interface

- MIB-II (RFC 1213)
- Bridge MIB (RFC 1493)
- RMON MIB (RFC 1757)
- 802.1Q VLAN/802.1p MIB (RFC 2674)
- IGMP MIB (RFC 2933)
- IF (Interface) MIB (RFC 2233)
- Ethernet-like MIB (RFC 1643)
- D-Link enterprise MIB

RMON Groups
1, 2, 3, 9 (Alarm, Statistics, History, Event)

IP Number Self-identification
Through DHCP client, Bootp client

Firmware Upgrade

TFTP client

Console Port
DB-9 RS-232 DCE

Power Input
- 100 to 120 VAC, 50/60 Hz or 200 to 240 VAC, 50/60 Hz
- Internal universal power supply

Redundant Power Backup Support
Connector to connect to external redundant power supply

Power Consumption
30 watts (max.) (without expansion modules)

60 x 60 mm DC fans x 1

Operating Temperature
0  to 40  C
Storage Temperature
-25   to 55  C

10% to 95% non-condensing
- 440 (W) x 309 (D) x 44 mm (H) (device only)
- 19-inch rack-mount width, 1 U height

4.4 kg (device only, without expansion modules)

Emission (EMI)
- FCC Class A
- CE Class A
- C-Tick
- BSMI Class A

CSA International


Order info

Stacking Master & Modular L2 Gigabit Switch
       4 10/100/1000BASE-T ports, 4 combo GBIC (SFP) slots, 2 expansion slots, redundant power support

Optional Expansion Module
         4 stacking ports (for use with DES-3226S switches)
DEM-340MG  4 SFP GBIC slots
DEM-340T       4 10/100/1000BASE-T ports

Optional Mini GBIC SFP Transceiver
DEM-310GT  SFP transceiver for 1000BASE-LX, single-mode fiber, max. distance 10km, 3.3V
DEM-311GT  SFP transceiver for 1000BASE-SX, multi-mode fiber, max. distance 550m, 3.3V
DEM-314GT  SFP transceiver for 1000BASE-LHX, single-mode fiber, max. distance 40km, 3.3V
DEM-315GT  SFP transceiver for 1000BASE-ZX, single-mode fiber, max. distance 80km, 3.3V

Optional Redundant Power Supply
  60 watts redundant power supply
DPS-800   2-slot redundant power supply chassis 



Support Resources