D-Link xStack DGS-3120-24TC User manual

xStack® DGS-3120 Series Managed Switch Web UI Reference Guide
i
Information in this document is subject to change without notice.
© 2010 D-Link Corporation. All rights reserved.
Reproduction of this document in any manner whatsoever without the written permission of D-Link Corporation is strictly forbidden.
Trademarks used in this text: D-Link and the D-LINK logo are trademarks of D-Link Corporation; Microsoft and Windows are registered
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D-Link Corporation disclaims any proprietary interest in trademarks and trade names other than its own.
March 2011 P/N 651G312XX025G

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Table of Contents
Intended Readers............................................................................................................................................................1
Typographical Conventions.............................................................................................................................................1
Notes, Notices and Cautions...........................................................................................................................................1
Chapter 1 Web-based Switch Configuration...........................................................................2
Introduction......................................................................................................................................................................2
Login to the Web Manager..............................................................................................................................................2
Web-based User Interface..............................................................................................................................................2
Areas of the User Interface..........................................................................................................................................3
Web Pages......................................................................................................................................................................4
Chapter 2 System Configuration..............................................................................................5
Device Information ..........................................................................................................................................................5
System Information Settings...........................................................................................................................................6
Port Configuration ...........................................................................................................................................................7
Port Settings................................................................................................................................................................7
Port Description Settings.............................................................................................................................................8
Port Error Disabled......................................................................................................................................................9
Jumbo Frame Settings ................................................................................................................................................9
PoE................................................................................................................................................................................10
PoE System Settings.................................................................................................................................................10
PoE Port Settings ......................................................................................................................................................11
Serial Port Settings .......................................................................................................................................................13
Warning Temperature Settings.....................................................................................................................................13
System Log configuration..............................................................................................................................................14
System Log Settings..................................................................................................................................................14
System Log Server Settings......................................................................................................................................15
System Log................................................................................................................................................................16
System Log & Trap Settings......................................................................................................................................16
System Severity Settings...........................................................................................................................................17
Time Range Settings.....................................................................................................................................................18
Port Group Settings (EI Mode Only) .............................................................................................................................18
Time Settings ................................................................................................................................................................19
User Accounts Settings.................................................................................................................................................19
Command Logging Settings..........................................................................................................................................21
Stacking.........................................................................................................................................................................21
Stacking Device Table...............................................................................................................................................23
Stacking Mode Settings.............................................................................................................................................23
Chapter 3 Management...........................................................................................................25
ARP...............................................................................................................................................................................25
Static ARP Settings...................................................................................................................................................25
Proxy ARP Settings (EI Mode Only)..........................................................................................................................26
ARP Table .................................................................................................................................................................26
Gratuitous ARP .............................................................................................................................................................27
Gratuitous ARP Global Settings................................................................................................................................27
Gratuitous ARP Settings............................................................................................................................................27
IPv6 Neighbor Settings (EI Mode Only)........................................................................................................................28
IP Interface....................................................................................................................................................................29
System IP Address Settings......................................................................................................................................29

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Interface Settings.......................................................................................................................................................30
Management Settings ...................................................................................................................................................33
Session Table................................................................................................................................................................34
Single IP Management..................................................................................................................................................35
Single IP Settings ......................................................................................................................................................37
Topology....................................................................................................................................................................37
Firmware Upgrade.....................................................................................................................................................43
Configuration File Backup/Restore............................................................................................................................44
Upload Log File .........................................................................................................................................................44
SNMP Settings..............................................................................................................................................................44
SNMP Global Settings...............................................................................................................................................45
SNMP Traps Settings................................................................................................................................................46
SNMP Linkchange Traps Settings ............................................................................................................................46
SNMP View Table Settings .......................................................................................................................................47
SNMP Community Table Settings.............................................................................................................................48
SNMP Group Table Settings.....................................................................................................................................49
SNMP Engine ID Settings .........................................................................................................................................50
SNMP User Table Settings........................................................................................................................................51
SNMP Host Table Settings........................................................................................................................................52
SNMPv6 Host Table Settings (EI Mode Only)...........................................................................................................53
RMON Settings..........................................................................................................................................................53
Telnet Settings ..............................................................................................................................................................54
Web Settings.................................................................................................................................................................54
Chapter 4 L2 Features.............................................................................................................55
VLAN.............................................................................................................................................................................55
802.1Q VLAN Settings ..............................................................................................................................................60
802.1v Protocol VLAN...............................................................................................................................................63
Asymmetric VLAN Settings .......................................................................................................................................65
GVRP.........................................................................................................................................................................65
MAC-based VLAN Settings.......................................................................................................................................67
Private VLAN Settings...............................................................................................................................................67
PVID Auto Assign Settings........................................................................................................................................69
Voice VLAN ...............................................................................................................................................................69
VLAN Trunk Settings.................................................................................................................................................72
Browse VLAN ............................................................................................................................................................72
Show VLAN Ports......................................................................................................................................................73
QinQ (EI Mode Only).....................................................................................................................................................73
QinQ Settings ............................................................................................................................................................75
VLAN Translation Settings ........................................................................................................................................76
Spanning Tree...............................................................................................................................................................77
STP Bridge Global Settings.......................................................................................................................................78
STP Port Settings......................................................................................................................................................80
MST Configuration Identification ...............................................................................................................................81
STP Instance Settings...............................................................................................................................................82
MSTP Port Information..............................................................................................................................................83
Link Aggregation ...........................................................................................................................................................83
Port Trunking Settings...............................................................................................................................................85
LACP Port Settings....................................................................................................................................................85
FDB...............................................................................................................................................................................87
Static FDB Settings ...................................................................................................................................................87

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MAC Notification Settings..........................................................................................................................................88
MAC Address Aging Time Settings...........................................................................................................................89
MAC Address Table ..................................................................................................................................................90
ARP & FDB Table......................................................................................................................................................90
L2 Multicast Control ......................................................................................................................................................91
IGMP Snooping .........................................................................................................................................................91
MLD Snooping...........................................................................................................................................................99
Multicast VLAN........................................................................................................................................................106
Multicast Filtering ........................................................................................................................................................113
IPv4 Multicast Filtering ............................................................................................................................................113
IPv6 Multicast Filtering ............................................................................................................................................116
Multicast Filtering Mode...........................................................................................................................................118
ERPS Settings (EI Mode Only)...................................................................................................................................119
LLDP ...........................................................................................................................................................................123
LLDP Global Settings ..............................................................................................................................................123
LLDP Port Settings..................................................................................................................................................124
LLDP Management Address List.............................................................................................................................125
LLDP Basic TLVs Settings ......................................................................................................................................125
LLDP Dot1 TLVs Settings........................................................................................................................................126
LLDP Dot3 TLVs Settings........................................................................................................................................127
LLDP Statistic System.............................................................................................................................................128
LLDP Local Port Information ...................................................................................................................................129
LLDP Remote Port Information ...............................................................................................................................130
NLB FDB Settings.......................................................................................................................................................131
Chapter 5 L3 Features...........................................................................................................132
IPv4 Default Route Settings (SI Mode Only)...............................................................................................................132
IPv4 Static/Default Route Settings (EI Mode Only).....................................................................................................132
IPv4 Route Table ........................................................................................................................................................133
IPv6 Static/Default Route Settings (EI Mode Only).....................................................................................................134
IP Forwarding Table....................................................................................................................................................134
Chapter 6 QoS........................................................................................................................135
802.1p Settings ...........................................................................................................................................................136
802.1p Default Priority Settings...............................................................................................................................136
802.1p User Priority Settings...................................................................................................................................137
Bandwidth Control.......................................................................................................................................................138
Bandwidth Control Settings.....................................................................................................................................138
Queue Bandwidth Control Settings .........................................................................................................................140
Traffic Control Settings................................................................................................................................................140
DSCP ..........................................................................................................................................................................143
DSCP Trust Settings ...............................................................................................................................................143
DSCP Map Settings.................................................................................................................................................144
HOL Blocking Prevention............................................................................................................................................145
Scheduling Settings ....................................................................................................................................................146
QoS Scheduling.......................................................................................................................................................146
QoS Scheduling Mechanism...................................................................................................................................147
Chapter 7 ACL........................................................................................................................148
ACL Configuration Wizard...........................................................................................................................................148
Access Profile List.......................................................................................................................................................149
Add an Ethernet ACL Profile ...................................................................................................................................150
Adding an IPv4 ACL Profile.....................................................................................................................................153

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Adding an IPv6 ACL Profile.....................................................................................................................................157
Adding a Packet Content ACL Profile .....................................................................................................................161
CPU Access Profile List..............................................................................................................................................165
Adding a CPU Ethernet ACL Profile........................................................................................................................166
Adding a CPU IPv4 ACL Profile..............................................................................................................................169
Adding a CPU IPv6 ACL Profile..............................................................................................................................173
Adding a CPU Packet Content ACL Profile.............................................................................................................176
ACL Finder..................................................................................................................................................................179
ACL Flow Meter...........................................................................................................................................................179
Egress Access Profile List (EI Mode Only).................................................................................................................183
Add an Ethernet ACL Profile ...................................................................................................................................183
Adding an IPv4 ACL Profile.....................................................................................................................................186
Adding an IPv6 ACL Profile.....................................................................................................................................190
Egress ACL Flow Meter (EI Mode Only).....................................................................................................................194
Chapter 8 Security.................................................................................................................197
802.1X.........................................................................................................................................................................197
802.1X Global Settings............................................................................................................................................200
802.1X Port Settings................................................................................................................................................201
802.1X User Settings...............................................................................................................................................202
Guest VLAN Settings...............................................................................................................................................203
RADIUS.......................................................................................................................................................................204
Authentication RADIUS Server Settings .................................................................................................................204
RADIUS Accounting Settings..................................................................................................................................206
RADIUS Authentication ...........................................................................................................................................206
RADIUS Account Client...........................................................................................................................................208
IP-MAC-Port Binding (IMPB) (EI Mode Only).............................................................................................................209
IMPB Global Settings ..............................................................................................................................................209
IMPB Port Settings ..................................................................................................................................................210
IMPB Entry Settings ................................................................................................................................................211
MAC Block List ........................................................................................................................................................211
DHCP Snooping ......................................................................................................................................................212
MAC-based Access Control (MAC).............................................................................................................................213
MAC-based Access Control Settings ......................................................................................................................213
MAC-based Access Control Local Settings.............................................................................................................215
MAC-based Access Control Authentication State...................................................................................................216
Web-based Access Control (WAC).............................................................................................................................216
WAC Global Settings...............................................................................................................................................219
WAC User Settings..................................................................................................................................................220
WAC Port Settings...................................................................................................................................................220
WAC Authentication State.......................................................................................................................................222
Compound Authentication...........................................................................................................................................222
Compound Authentication Settings.........................................................................................................................222
Compound Authentication Guest VLAN Settings (EI Mode Only)...........................................................................224
Port Security................................................................................................................................................................225
Port Security Settings..............................................................................................................................................225
Port Security VLAN Settings ...................................................................................................................................227
Port Security Entries................................................................................................................................................227
ARP Spoofing Prevention Settings .............................................................................................................................228
BPDU Attack Protection..............................................................................................................................................229
Loopback Detection Settings ......................................................................................................................................230

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Traffic Segmentation Settings.....................................................................................................................................231
NetBIOS Filtering Settings..........................................................................................................................................232
DHCP Server Screening.............................................................................................................................................233
DHCP Server Screening Port Settings....................................................................................................................233
DHCP Offer Permit Entry Settings ..........................................................................................................................234
Access Authentication Control....................................................................................................................................235
Enable Admin ..........................................................................................................................................................236
Authentication Policy Settings.................................................................................................................................237
Application Authentication Settings.........................................................................................................................237
Authentication Server Group Settings.....................................................................................................................238
Authentication Server Settings................................................................................................................................239
Login Method Lists Settings ....................................................................................................................................240
Enable Method Lists Settings..................................................................................................................................241
Local Enable Password Settings.............................................................................................................................242
SSL Settings................................................................................................................................................................243
SSH.............................................................................................................................................................................245
SSH Settings ...........................................................................................................................................................246
SSH Authentication Method and Algorithm Settings...............................................................................................246
SSH User Authentication List..................................................................................................................................248
Trusted Host Settings..................................................................................................................................................249
Safeguard Engine Settings .........................................................................................................................................250
Chapter 9 Network Application ............................................................................................253
DHCP..........................................................................................................................................................................253
DHCP Relay ............................................................................................................................................................253
DHCP Local Relay Settings.....................................................................................................................................260
SNTP...........................................................................................................................................................................260
SNTP Settings.........................................................................................................................................................260
Time Zone Settings .................................................................................................................................................261
Flash File System Settings..........................................................................................................................................262
Chapter 10 OAM.......................................................................................................................265
CFM.............................................................................................................................................................................265
CFM Settings...........................................................................................................................................................265
CFM Port Settings ...................................................................................................................................................271
CFM MIPCCM Table ...............................................................................................................................................272
CFM Loopback Settings..........................................................................................................................................272
CFM Linktrace Settings...........................................................................................................................................273
CFM Packet Counter...............................................................................................................................................274
CFM Fault Table......................................................................................................................................................275
CFM MP Table ........................................................................................................................................................276
Ethernet OAM..............................................................................................................................................................276
Ethernet OAM Settings............................................................................................................................................276
Ethernet OAM Configuration Settings.....................................................................................................................277
Ethernet OAM Event Log.........................................................................................................................................278
Ethernet OAM Statistics ..........................................................................................................................................279
Cable Diagnostics .......................................................................................................................................................280
Chapter 11 Monitoring ............................................................................................................282
Utilization.....................................................................................................................................................................282
CPU Utilization ........................................................................................................................................................282
DRAM & Flash Utilization........................................................................................................................................283
Port Utilization .........................................................................................................................................................283

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Statistics......................................................................................................................................................................284
Port Statistics...........................................................................................................................................................284
Packet Size..............................................................................................................................................................292
Mirror...........................................................................................................................................................................294
Port Mirror Settings..................................................................................................................................................294
RSPAN Settings ......................................................................................................................................................294
sFlow (EI Mode Only)..................................................................................................................................................296
sFlow Global Settings..............................................................................................................................................296
sFlow Analyzer Server Settings ..............................................................................................................................296
sFlow Flow Sampler Settings..................................................................................................................................297
sFlow Counter Poller Settings.................................................................................................................................298
Ping Test.....................................................................................................................................................................299
Trace Route.................................................................................................................................................................300
Peripheral....................................................................................................................................................................302
Device Environment ................................................................................................................................................302
Chapter 12 Save and Tools.....................................................................................................303
Save Configuration / Log.............................................................................................................................................303
Stacking Information ...................................................................................................................................................303
Download firmware .....................................................................................................................................................305
Download Firmware From TFTP.............................................................................................................................305
Download Firmware From HTTP.............................................................................................................................305
Upload Firmware.........................................................................................................................................................306
Upload Firmware To TFTP......................................................................................................................................306
Download Configuration..............................................................................................................................................307
Download Configuration From TFTP.......................................................................................................................307
Download Configuration From HTTP ......................................................................................................................308
Upload Configuration ..................................................................................................................................................308
Upload Configuration To TFTP................................................................................................................................308
Upload Configuration To HTTP...............................................................................................................................309
Upload Log File...........................................................................................................................................................310
Upload Log To TFTP...............................................................................................................................................310
Upload Log To HTTP...............................................................................................................................................310
Reset...........................................................................................................................................................................311
Reboot System............................................................................................................................................................311
Appendix Section........................................................................................................................313
Appendix A Mitigating ARP Spoofing Attacks Using Packet Content ACL............................................................313
How Address Resolution Protocol works ................................................................................................................313
How ARP Spoofing Attacks a Network....................................................................................................................315
Prevent ARP Spoofing via Packet Content ACL.....................................................................................................316
Configuration ...........................................................................................................................................................316
Appendix B Password Recovery Procedure ..........................................................................................................319
Appendix C System Log Entries.............................................................................................................................320
Appendix D Trap Log Entries .................................................................................................................................330

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Intended Readers
Typographical Conventions
Notes, Notices and Cautions
Safety Instructions
General Precautions for Rack-Mountable Products
Protecting Against Electrostatic Discharge
The DGS-3120 Series Web UI Reference Guide contains information for setup and management of the Switch.
This manual is intended for network managers familiar with network management concepts and terminology.
Typographical Conventions
Convention Description
[ ] In a command line, square brackets indicate an optional entry. For example: [copy
filename] means that optionally you can type copy followed by the name of the file.
Do not type the brackets.
Bold font Indicates a button, a toolbar icon, menu, or menu item. For example: Open the File
menu and choose Cancel. Used for emphasis. May also indicate system messages
or prompts appearing on screen. For example: You have mail. Bold font is also
used to represent filenames, program names and commands. For example: use the
copy command.
Boldface Typewriter
Font
Indicates commands and responses to prompts that must be typed exactly as
printed in the manual.
Initial capital letter Indicates a window name. Names of keys on the keyboard have initial capitals. For
example: Click Enter.
Menu Name > Menu
Option Menu Name > Menu Option Indicates the menu structure. Device > Port > Port Properties means the Port Properties menu option under the Port menu option that
is located under the Device menu.
Notes, Notices and Cautions
A NOTE indicates important information that helps make better use of the device.
A NOTICE indicates either potential damage to hardware or loss of data and tells how to avoid the
problem.
A CAUTION indicates a potential for property damage, personal injury, or death.

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Chapter 1 Web-based Switch Configuration
Introduction
Login to the Web Manager
Web-based User Interface
Web Pages
Introduction
All software functions of the DGS-3120 Series switches can be managed, configured and monitored via the
embedded web-based (HTML) interface. Manage the Switch from remote stations anywhere on the network
through a standard browser. The browser acts as a universal access tool and can communicate directly with the
Switch using the HTTP protocol.
The Web-based management module and the Console program (and Telnet) are different ways to access the
same internal switching software and configure it. Thus, all settings encountered in web-based management are
the same as those found in the console program.
Login to the Web Manager
To begin managing the Switch, simply run the browser installed on your computer and point it to the IP address you
have defined for the device. The URL in the address bar should read something like: http://123.123.123.123, where
the numbers 123 represent the IP address of the Switch.
NOTE: The factory default IP address is 10.90.90.90.
This opens the management module's user authentication window, as seen below.
Figure 1–1 Enter Network Password window
Leave both the User Name field and the Password field blank and click OK. This will open the Web-based user
interface. The Switch management features available in the web-based manager are explained below.
Web-based User Interface
The user interface provides access to various Switch configuration and management windows, allows you to view
performance statistics, and permits you to graphically monitor the system status.

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Areas of the User Interface
The figure below shows the user interface. Three distinct areas divide the user interface, as described in the table.
Figure 1–2 Main Web-Manager page
Area
Number Function
Area 1 Select the menu or window to display. Open folders and click the hyperlinked menu buttons
and subfolders contained within them to display menus. Click the D-Link logo to go to the D-
Link website.
Area 2
Presents a graphical near real-time image of the front panel of the Switch. This area displays
the Switch's ports, console and management port, showing port activity.
Some management functions, including save, reboot, download and upload are accessible
here.
Area 3 Presents switch information based on user selection and the entry of configuration data.
AREA 2
AREA 1
AREA 3

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Web Pages
When connecting to the management mode of the Switch with a web browser, a login screen is displayed. Enter a
user name and password to access the Switch's management mode.
Below is a list of the main folders available in the Web interface:
System Configuration - In this section the user will be able to configure features regarding the Switch’s
configuration.
Management - In this section the user will be able to configure features regarding the Switch’s management.
L2 Features - In this section the user will be able to configure features regarding the Layer 2 functionality of the
Switch.
L3 Features - In this section the user will be able to configure features regarding the Layer 3 functionality of the
Switch.
QoS - In this section the user will be able to configure features regarding the Quality of Service functionality of the
Switch.
ACL - In this section the user will be able to configure features regarding the Access Control List functionality of the
Switch.
Security - In this section the user will be able to configure features regarding the Switch’s security.
Network Application - In this section the user will be able to configure features regarding network applications
handled by the Switch.
OAM - In this section the user will be able to configure features regarding the Switch’s operations, administration
and maintenance (OAM).
Monitoring - In this section the user will be able to monitor the Switch’s configuration and statistics.
NOTE: Be sure to configure the user name and password in the User Accounts menu before
connecting the Switch to the greater network.

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Chapter 2 System Configuration
Device Information
System Information Settings
Port Configuration
PoE
Serial Port Settings
Warning Temperature Settings
System Log configuration
Time Range Settings
Port Group Settings (EI Mode Only)
Time Settings
User Accounts Settings
Command Logging Settings
Stacking
Device Information
This window contains the main settings for all the major functions for the Switch. It appears automatically when you
log on to the Switch. To return to the Device Information window after viewing other windows, click the DGS-3120
Series link.
The Device Information window shows the Switch’s MAC Address (assigned by the factory and unchangeable), the
Boot PROM Version, Firmware Version, Hardware Version, and many other important types of information. This is
helpful to keep track of PROM and firmware updates and to obtain the Switch’s MAC address for entry into another
network device’s address table, if necessary. In addition, this window displays the status of functions on the Switch
to quickly assess their current global status.
Many functions are hyper-linked for easy access to enable quick configuration from this window.
Figure 2–1 Device Information window (SI Mode Only)

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Figure 2–2 Device Information window (EI Mode Only)
Click the Settings
link to navigate to the appropriate feature page for configuration.
System Information Settings
The user can enter a System Name, System Location, and System Contact to aid in defining the Switch.
To view the following window, click System Configuration > System Information Settings, as show below:
Figure 2–3 System Information Settings window
The fields that can be configured are described below:
Parameter Description
System Name Enter a system name for the Switch, if so desired. This name will identify it in the
Switch network.
System Location
Enter the location of the Switch, if so desired.

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System Contact
Enter a contact name for the Switch, if so desired.
Click the Apply button to implement changes made.
Port Configuration
Port Settings
This page used to configure the details of the switch ports.
To view the following window, click System Configuration > Port Configuration > Port Settings, as show below:
Figure 2–4 Port Settings window
To configure switch ports:
1. Choose the port or sequential range of ports using the From Port and To Port pull-down menus.
2. Use the remaining pull-down menus to configure the parameters described below:
The fields that can be configured are described below:
Parameter Description
Unit
Select the unit you wish to configure.
From Port / To Port
Select the appropriate port range used for the configuration here.
State
Toggle the State field to either enable or disable a given port or group of ports.
Speed/Duplex Toggle the Speed/Duplex field to select the speed and full-duplex/half-duplex state of the
port. Auto denotes auto-negotiation among 10, 100 and 1000 Mbps devices, in full- or
half-duplex (except 1000 Mbps which is always full duplex). The Auto setting allows the
port to automatically determine the fastest settings the device the port is connected to
can handle, and then to use those settings. The other options are 10M Half, 10M Full,
100M Half, 100M Full, 1000M Full_Master, 1000M Full_Slave, and 1000M Full. There is
no automatic adjustment of port settings with any option other than Auto.
The Switch allows the user to configure three types of gigabit connections; 1000M
Full_Master, 1000M Full_Slave, and 1000M Full. Gigabit connections only support full
duplex connections and take on certain characteristics that are different from the other
choices listed.

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The 1000M Full_Master and 1000M Full_Slave parameters refer to connections running
a 1000BASE-T cable for connection between the Switch port and other device capable
of a gigabit connection. The master setting (1000M Full_Master) will allow the port to
advertise capabilities related to duplex, speed and physical layer type. The master
setting will also determine the master and slave relationship between the two connected
physical layers. This relationship is necessary for establishing the timing control between
the two physical layers. The timing control is set on a master physical layer by a local
source. The slave setting (1000M Full_Slave) uses loop timing, where the timing comes
from a data stream received from the master. If one connection is set for 1000M
Full_Master, the other side of the connection must be set for 1000M Full_Slave. Any
other configuration will result in a link down status for both ports.
Flow Control Displays the flow control scheme used for the various port configurations. Ports
configured for full-duplex use 802.3x flow control, half-duplex ports use backpressure
flow control, and Auto ports use an automatic selection of the two. The default is
Disabled.
Connection
Here the current connection speed will be displayed.
MDIX Auto - Select auto for auto sensing of the optimal type of cabling.
Normal - Select normal for normal cabling. If set to normal state, the port is in MDI mode
and can be connected to a PC NIC using a straight-through cable or a port (in MDI
mode) on another switch through a cross-over cable.
Cross - Select cross for cross cabling. If set to cross state, the port is in MDIX mode, and
can be connected to a port (in MDI mode) on another switch through a straight cable.
Address Learning Enable or disable MAC address learning for the selected ports. When Enabled,
destination and source MAC addresses are automatically listed in the forwarding table.
When address learning is Disabled, MAC addresses must be manually entered into the
forwarding table. This is sometimes done for reasons of security or efficiency. See the
section on Forwarding/Filtering for information on entering MAC addresses into the
forwarding table. The default setting is Enabled.
Medium Type
If configuring the Combo ports, this defines the type of transport medium to be used.
Click the Apply button to implement changes made.
Click the Refresh button to refresh the display section of this page.
Port Description Settings
The Switch supports a port description feature where the user may name various ports.
To view the following window, click System Configuration > Port Configuration > Port Description Settings, as
show below:
Figure 2–5 Port Description Settings window

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The fields that can be configured are described below:
Parameter Description
Unit
Select the unit you wish to configure.
From Port / To Port
Select the appropriate port range used for the configuration here.
Medium Type Specify the medium type for the selected ports. If configuring the Combo ports, the
Medium Type defines the type of transport medium to be used, whether Copper or Fiber.
Description
Users may then enter a description for the chosen port(s).
Click the Apply button to implement changes made.
Port Error Disabled
The following window displays the information about ports that have been disconnected by the Switch when a
packet storm occurs or a loop was detected.
To view the following window, click System Configuration > Port Configuration > Port Error Disabled, as show
below:
Figure 2–6 Port Error Disabled
The fields that can be displayed are described below:
Parameter Description
Port
Display the port that has been error disabled.
Port State
Describe the current running state of the port, whether enabled or disabled.
Connection Status
Display the uplink status of the individual ports, whether enabled or disabled.
Reason Describe the reason why the port has been error-disabled, such as it has become a
shutdown port for storm control.
Jumbo Frame Settings
The Switch supports jumbo frames. Jumbo frames are Ethernet frames with more than 1,518 bytes of payload. The
Switch supports jumbo frames with a maximum frame size of up to 13312 bytes.
To view the following window, click System Configuration > Port Configuration > Jumbo Frame Settings, as
show below:
Figure 2–7 Jumbo Frame Settings window
The fields that can be configured are described below:
Parameter Description

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Jumbo Frame Use the radio buttons to enable or disable the Jumbo Frame function on the Switch. The
default is Disabled. When disabled, the maximum frame size is 1536 bytes. When
enabled, the maximum frame size is 13312 bytes.
Click the Apply button to implement changes made.
PoE
The DGS-3120-24PC and DGS-3120-48PC switches support Power over Ethernet (PoE) as defined by the IEEE
802.3af and 802.3at. All ports can support PoE up to 30W. Ports 1-24 can supply about 48 VDC power to Powered
Devices (PDs) over Category 5 or Category 3 UTP Ethernet cables. The Switch follows the standard PSE (Power
Sourcing Equipment) pinout Alternative A, whereby power is sent out over pins 1, 2, 3 and 6. The Switches work
with all D-Link 802.3af capable devices.
The Switch includes the following PoE features:
•Auto-discovery recognizes the connection of a PD (Powered Device) and automatically sends power to it.
•The Auto-disable feature occurs under two conditions: firstly, if the total power consumption exceeds the
system power limit; and secondly, if the per port power consumption exceeds the per port power limit.
•Active circuit protection automatically disables the port if there is a short. Other ports will remain active.
Based on 802.3af/at PDs receive power according to the following classification:
Class Maximum power available to PD
0 15.4W
1 4.0W
2 7.0W
3 15.4W
4 15.4W
To configure the PoE features on the Switch, click System Configuration >PoE. The PoE System Settings
window is used to assign a power limit and power disconnect method for the whole PoE system. To configure the
Power Limit for the PoE system, enter a value between 1W and 370W for the Switch in the Power Limit field.
When the total consumed power exceeds the power limit, the PoE controller (located in the PSE) disconnects the
power to prevent overloading the power supply.
PoE System Settings
To view the following window, click System Configuration > PoE > PoE System Settings, as show below:
PSE provides power according to the following classification:
Class Max power used by PSE
0 16.2W
1 4.2W
2 7.4W
3 16.2W
User define
31.2W

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Figure 2–8 PoE System Settings window
The following parameters can be configured:
Parameter Description
Unit
Select the unit you wish to configure. Tick the All check box to select all units.
Power Limit (37-
740) Sets the limit of power to be used from the Switch’s power source to PoE ports. The user
may configure a Power Limit between 37W and 740W for the DGS-3120-24PC and
DGS-3120-48PC. The default setting is 740W.
Power Disconnect
Method The PoE controller uses either Deny Next Port or Deny Low Priority Port to offset the
power limit being exceeded and keeps the Switch’s power at a usable level. Use the drop
down menu to select a Power Disconnect Method. The default Power Disconnect
Method is Deny Next Port. Both Power Disconnection Methods are described below:
Deny Next Port – After the power limit has been exceeded, the next port attempting to
power up is denied, regardless of its priority. If Power Disconnection Method is set to
Deny Next Port, the system cannot utilize out of its maximum power capacity. The
maximum unused watt is 19W.
Deny Low Priority Port – After the power limit has been exceeded, the next port
attempting to power up causes the port with the lowest priority to shut down so as to
allow the high-priority and critical priority ports to power up.
Legacy PD
Use the drop-down menu to enable or disable detecting legacy PDs signal.
Click Apply to implement changes made.
PoE Port Settings
To view the following window, click System Configuration > PoE > PoE Port Settings, as show below:

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Figure 2–9 PoE Port Settings window
The following parameters can be configured:
Parameter Description
Unit
Select the unit you wish to configure.
From Port / To Port
Select a range of ports from the pull-down menus to be enabled or disabled for PoE.
State
Use the pull-down menu to enable or disable ports for PoE.
Time Range Select a range of the time to the port set as POE. If Time Range is configured, the power
can only be supplied during the specified period of time.
Priority Use the pull-down menu to select the priority of the PoE ports. Port priority determines
the priority which the system attempts to supply the power to the ports. There are three
levels of priority that can be selected, Critical, High, and Low. When multiple ports
happen to have the same level of priority, the port ID will be used to determine the
priority. The lower port ID has higher priority. The setting of priority will affect the order of
supplying power. Whether the disconnect method is set to deny low priority port, the
priority of each port will be used by the system to manage the supply of power to ports.
Power Limit This function is used to configure the per-port power limit. If a port exceeds its power
limit, it will shut down.
Based on 802.3af/802.3at, there are different PD classes and power consumption
ranges;
Class 0 – 0.44~15.4W
Class 1 – 0.44~4.0W
Class 2 – 4~7.0W
Class 3 – 7~15.4W
Class 4 – 15.4W
The following is the power limit applied to the port for these five classes. For each class,
the power limit is a little more than the power consumption range for that class. This
takes into account any power loss on the cable. Thus, the following are the typical
values;